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Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 48
Design of Plumbing System And Variation Of Hydrostatic Pressure For Eighteen Storey High
Rise Building
Khin Zar Ni Myint(1), Thant Zin Oo(2)
(1)Technological University (Thanlyin), Myanmar
(2) Technological University (Thanlyin), Myanmar
Email; [email protected] ABSTRACT: This paper suggests a technique for
including pressure dependent demand and leakage
terms in simulation models for water distribution
systems. In this paper, the plumbing system is designed
for Yadanar Hninsi Residence, Yangon, Myanmar. It
was eighteen storeys, building floor area (669.37 m2)
and building height (61.4 m).1st level included 3 rooms
for commercial rooms. 2nd level included 12 rooms for
residential rooms. From 3rd to 9th and 11th to 18th level
of each floor include 8 rooms for residential rooms. In
10th level included 6 rooms. Among them 4 for
residential and others were halls. There were (696)
persons in this building. According to the calculated
results, the ground tank size and roof tank size are
(8m×7m×3m) and (7m×6m×2m). The observed values
of transfer pipe size and distribution pipe size are 80
mm. The flow rate of transfer pump and booster pump
are (36 m3/ hr). The power of transfer pump and booster
pump are (13 hp) and (4.3 hp). The transfer pump head
and booster pump head are 68.68m and 20.02m
respectively. The hydrostatic pressures are increasing
from 18th floor to 1st floor, when before using the
Pressure Reducing Valve and Booster Pump. The
pressures of 18th , 17th , 16th floors decrease below
1bar and 9th to 1st floors increase above 3 bars.
KEYWORDS: High rise building, Water supply
system, Pumps, Pressure reducing valve, MATLAB
1. INTRODUCTION
Water is a natural resource that is necessary for the
provisions of life and environmental systems, and a key
resource to social and economic development, national
and international organizations from all over the world.
Pipes, drains, fittings, valves and fixtures are installed
for the distribution of water at plumbing system,
heating and washing and waterborne waste removal.
Plumbing system is included a water supply and
distribution pipes, plumbing fixtures, traps, and water
using equipment. In this paper, the plumbing system is
designed for Yadanar Hninsi Residence, Yangon,
Myanmar. These building floor area is (669.37 m2) and
building height is (61.4 m).This building is eighteen
storey residential building, which consists of 55.7418
m2 and 111.4836m2 units. There are 138 residential
rooms and 3 commercial rooms. The plumbing system
includes water supply and distribution pipes: riser, up
feed or down feed distribution pipes, underground tank,
overhead tank, plumbing fixtures, pumps and pressure
reducing valve.
In general, water is one of the key reasons for
human survival and society. Water is careful to be the
most important factor behind the survival of life on
Earth. Daily water requirement for one person is 40
gallons per day according to Singapore Standard CP 48
from Table -1 [1]. Increasing population density and
land prices in cities make high-rise building an
attractive construction option. Such buildings have to be
supplied with water, which requires so-called transfer
pump system and booster pump system. The booster
pump is used to increase the water pressure in order to
reach the uppermost floors in high rise buildings. The
typical layout of pressure boosting systems for water
supply in high-rise buildings is characterized by the
interconnection of components from different physical
domains. The pressure reducing valves are installed in
this high rise building. By using the pressure reducing
valves to prevent excessive pressure. Flow and pressure
demands at any point of the plumbing system are
determined by the calculation are as follows: (i) Sources
of Water, (ii) Water Distribution, (iii) Water Demand,
(iv) Water Storage, (v)Pressure Requirements, (vi) Pipe
sizing,(vii) Pump Selection and (viii)Pressure Reducing
Valve.
2. METHOLOGY
The high rise building tendency increases energy
required for water supply. In this paper, the plumbing
system for the eighteen storeyed high rise building is
designed as per CP 48 code and CQHP (Committee for
Quality control of High-rise building construction
Projects).The result of before and after using Pressure
Reducing Valve and Booster Pump are compared by
using MATLAB.
3. DESIGN CALCULATION
Water Reducing Valves and Pressure Reducing
Valves are installed in residential water systems to
reduce and stabilize inlet pressures from mains water
supplies or boosted water systems, which generally are
too high and variable for domestic appliances to
function correctly. The water from the ground tank is
pumped to the overhead tank by using the transfer
pump. A booster pump is a pump that increases fluid
pressure while maintaining a specified flow rate. The
pressures under 1.5 bar are raised by using the booster
pump. The process of plumbing cycle consists of
source, treatment, supply, distribution, use, collection
and disposal section are shown in Figure - 1.
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 49
Fig 1.Plumbing cycle
3.1 Water supply system and tank size
Treated water is used for daily activities such as
cleansing, washing and plumbing. A proper water
distribution system is needed to ensure a constant flow
of water supply. The type of distribution system largely
depends on the structure of the area. There are three
types of distribution systems which are gravity
distribution system, pumped distribution system and
gravity and pumped combination system. The gravity
and pumped combination system is the most commonly
used system. It is economical, efficient and reliable
system. It uses a pumped system to get the water from
the sources to the treatment plants, the ground tank and
the overhead tanks and then changes to a gravity
distribution system to supply water to the service area
(15th floor to 1st floor). The booster pump is used not to
be enough the water pressure in order to the uppermost
three floor (18th floor to 16th floor) in high rise building.
Human life, as with all animal and plant life on the
Earth, is dependent upon water. Not only the water is
needed to grow the food, generate the power of body,
and run the industries but it is a basic part of the daily
lives. The water is need for the bodies every day to
continue functioning. ‘Basic needs of about 40 gallons
per day according CP 48’ from Table-1 [ 1 ].
Table 1. Recommended Minimum Storage of Cold
Water for Potable Purposes
Type of building Storage in litres
per head
Storage in
gallons per
day
Dwelling houses
and flats
150 40
Hostels
90 24
Hotels
135 36
Schools
15 4
The designed building has eighteen floors. The
first floor has 3 commercial rooms (55.7418 m2).The
second floor to eighteen floor (55.7418 m2 and
111.4836 m2) have 76 and 62 residential rooms. The
number of occupants has 5 people in each residential
room [1]. So the total number of occupants was 696
persons. So total daily water required for whole
building was 27840 gallons per day. It includes the
need for water domestic hygiene sufficient to maintain
health and to maintain a basic standard of personal. The
effects of insufficient water supply cause sickness, high
unit costs, time and energy expended in daily collection,
etc. Provision of basic daily water needs is yet to be
regarded by several countries as a human right finished
water is rising, more in some areas of the world than in
others. [1]
The effective capacity of ground tank and roof tank
sizes can be calculated by equation as follow:
Effective capacity of ground tank =Daily water requirement
0.5 (1)
So the required ground tank size is (8m × 7m × 3m).
Roof tank capacity = 50 % of total domestic demand
per day (2)
Effective capacity of roof tank =0.75
capacity tank Roof (3)
The required roof tank size is two units of (7m length ×
6m width × 2m height) tank. [2]
3.2 Loading units
In this high rise building, there are three
commercial rooms (55.7418 m2), 76 residential rooms
(55.7418 m2) and 62 residential rooms (111.4836
m2).The first floor has three commercial rooms. The
total number of loading units for three commercial
rooms is 15 units [3]. The second floor to eighteenth
floor has 76 residential rooms (55.7418 m2) and 62
residential rooms (111.4836 m2). The loading unit each
of the 55.7418 m2 residential room is 12 units and
111.4836 m2 residential room is 25 units. So the total
number of loading units for second floor to eighteenth
floor is 2462 units. Therefore, the total number of
loading units for the whole building is 2477 units
[3].Table - 2 describes the loading units and flow rates
for each residential room and commercial room [1].
Table 2. Loading units and flow rates
Room
(m2)
Total Loading
Units
(units)
Flow Rates
(m3/s)
55.7418
m2,commercial 5 0.315 × 10-3
55.7418 m2
,residential 12 0.641 × 10-3
111.4836 m2
,residential 25 0.798 × 10-3
3.3 Pipe sizes
The transfer pipe size is used to transfer of the
water from ground tank to overhead tank. The time
taken to fill the overhead tank is assumed 2 hours.
Transfer pump flow rates can get from the roof tank
capacity divided by refilling time. To find the pipe sizes
the flow rates is added 5 % extra use for safety [4].
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 50
Transfer pipe size can be calculated by the continuity
equation as follow:
Q = A V (4)
Where, Q = flow rate of water (m3/s)
A = area of the pipe (m2)
V = velocity of the fluid (m/s)
The velocity of water is assumed as 2.1 m/s for
distribution pipe sizes and 0.6 m/s for branch pipe sizes
[3]. The distribution pipe sizes from roof tank to
plumbing fixtures are calculated by the continuity
equation. The gravity flow is used for distributing the
water from roof tank to fixtures (15th floor to 1st floor).
The distribution pipe sizes from booster pump are used
for the three uppermost floors. The booster pump is
used to distribute the water because of the hydrostatic
pressure is not to be enough the three uppermost floors.
The branch pipes from distribution pipe are distributed
to the corresponding rooms. Branch pipe size can be
calculated by the continuity equation.
Table 3. Legends for plumbing fixtures
Symbol Description
WC Water Closet
WB Wash Basin
SH Shower
SK Sink
WM Washing Machine
SK Sink
3.4 Pump power and pump size
Pump is a device that increases pressure while
maintaining a desired flow rate. The transfer pump is
used to transfer the water from ground tank to roof tank.
A booster pump is a pump that increases fluid pressure
while maintaining a specified flow rate. The pressures
under 1.5 bar are raised by using the booster pump. The
water pressure is supplied by using the booster pump
cannot reach the three uppermost floors on the building.
To calculate the transfer pump power, the daily water
demand of the building, the operating hours of the
pump, total head to be pumped and the flow rates of
water must be considered. Normally the filling times of
the pump is taken as 2 to 4 hours. The shaft power of
the pump can be determined by dividing water power
by the pump efficiency. The power of transfer pump
and booster pump can be calculated by:
Transfer and Booster pump power = 𝜌𝑔𝑄𝐻/ƞ (5)
Where, ρ = density of water (kg / m3)
G = acceleration due to gravity (m/s2)
Q = flow rate of water (m3/s)
H = Total head (m) [5]
To get the pump power above the equation ( 5 )
must be know the total head , the flow rates and pump
efficiency .The pump efficiency is assumed 65% .
The total head for the transfer pump can be
calculated by :
Total head = Static head + Total friction loss (6)
Fig 2.Heads in transfer pump system
The total head for the booster pump can be calculated
by :
Total head = Static head + Total friction loss +
Design pressure (7)
[4]
Fig 3.Heads in booster pump system
3.5 Pressure reducing valves and water reducing
valves at inlet of each floor
Water Reducing Valves and Pressure Reducing
Valves are installed in residential water systems to
reduce and stabilize inlet pressures from mains water
supplies or boosted water systems, which generally are
too high and variable for domestic appliances to
function correctly. They are often designed to prevent
excessive pressure at water outlets such as taps, basins,
toilets, dishwashers and other appliances. Hydrostatic
pressure exerted by a fluid at hydrostatic equilibrium on
the contact surface due to gravity. Hydrostatic pressure
increases in proportion to depth measured from the
water surface. The weight of the fluid increased because
of exerting downward force from above. The floors
below have the value of the static head reaching more
than 3 bars, which is not allowable. To avoid this high
pressure need additional pressure reducing valve. The
pressures over 3 bars are controlled by adding the
pressure reducing valve. On the other hand, floor 9 and
the floors below it, have the value of the static head
reaching more than 3 bars, which is not allowable. To
avoid this high pressure need additional pressure
reducing valve. So the pressure reducing valve
additional at 9th floor .The hydrostatic pressure can be
calculated by:
P = γh (8)
Where,
P = Hydrostatic pressure in bar
γ = Specific weight in N/m3
h = Pressure head in m
The pressure reducing valve is set up to decrease
the fluid pressure from 9th to 1st floors. The variation of
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 51
hydrostatic pressure after using booster pump and
pressure reducing valve can be calculated by:
P = Hydrostatic pressure + Design Pressure of booster
pump (9)
P = Hydrostatic pressure + Out put pressure of pressure
reducing valve (10)
4. RESULT AND DISCUSSION
In this paper, the plumbing system is designed for
Yadanar Hninsi Residence, Yadanar Hninsi Street,
Tharkayta Township, Yangon Division, Myanmar. . It
is 669.37 m2 (Area) and 61.4 m (Height).After
calculating the daily water requirement, tank sizes, pipe
sizing, pump flow rate, and pump selection, it can be
compared the differences between existing and results.
It is shown in Table 4, 5, 6 and 7.
Table 4. Comparisons of calculated results and existing
data for branches pipe sizes
No Description Symbol Result
Data
Existing
Data
1
Branches pipe size
for (55.748 m2,
commercial room)
(Dbr)1 32mm 25mm
2
Branches pipe size
for (55.748 m2,
residential)
(Dbr)2 40mm 32mm
3
Branches pipe size
for (111.4836
m2,residential)
(Dbr)3 50mm 50mm
Table 5. Comparisons of calculated results and existing
data for distribution pipe sizes for transfer pump
No Description Symbol Result
Data
Existing
Data
1
Standard
transfer
pipe size
Dtr 80 mm 100mm
2
Distribution
pipe size
(15th to 3rd )
(Ddi )1 100mm 100mm
3
Distribution
pipe size
(2nd to 1st )
(Ddi )2 40mm 50mm
Table 6. Comparisons of calculated results and existing
data for distribution pipe sizes for booster pump
No Description Symbol Result
Data
Existing
Data
1
Horizontal
distribution
pipe size for
booster pump
(Ddi )3 80mm 100mm
2
Distribution
pipe size for
booster pump
(18th to 16th )
(Ddi )4 50mm 80mm
Table 7. Comparisons of calculated results and existing
data for pump flow rate, pump head and pump power
for transfer pump and booster pump
No Description Symbol Result
Data
Existing
Data Unit
1
Transfer
pump flow
rate
Qtr 36 60 m3 /
hr
2
Booster
pump flow
rate
Qboost 36 42 m3 /
hr
3 Transfer
pump head Htr 68.68 96 m
4 Booster
pump head Hboost 21.22 31 m
5 Transfer
pump power Ptr 9.6 15 KW
6 Booster
pump power Pboost 3.23 4 KW
The pipe sizes changed in above the comparisons
of Table 4, 5 and 6, because it has different area of the
rooms and the usages of the fixtures are not the same. In
Table 7, the existing data of transfer pump flow rate, the
booster pump flow rate, the transfer pump head, the
booster pump head, the transfer pump power and the
booster pump power are larger than the calculated
results by using equation ( 5 ) , ( 6 ) and ( 7 ). If the
transfer pump flow rate Qtr and the booster pump flow
rate Qboost are changed, the pump sizes, pipe diameters
and water velocities will be changed. Transfer pump
can be replaced by a booster pump. However the
booster pump cannot be a substitute for a transfer pump.
Transfer pumps are used in that area where systems
need more pressure (low to high). Booster pumps are
used in that area where system need low pressure.
Fig 4.Before using the pressure reducing valve and
booster pump
Fig 5.After using the pressure reducing valve and
booster pump
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 52
The result of the variation of pressure before and
after using the booster pump and pressure reducing
valve are compared by using MATLAB software. After
that the result charts of comparison are shown in Fig.4
and 5. In Fig. 4, the hydrostatic pressures are increasing
from 18th floor to 1st floor, when before using the
Pressure Reducing Valve and Booster Pump. The
pressures of 18th, 17th , 16th floors decrease below 1bar
and 9th to 1st floors increase above 3 bars when before
using the Pressure Reducing Valve and Booster Pump.
From Fig .5, the pressure of 18th, 17th, 16th floors
increase and 9th to 1st floors decrease by using booster
pump and pressure reducing valve. By using the booster
pump and pressure reducing valve, water pressure in all
stories reach to the optimum water pressure range
(between 1 bar and 3 bar). This Fig .4 and Fig.5 are by
making the comparison of before and after booster
pump and pressure reducing valve.
5. CONCLUSIONS
Water is a basic human need. Water supply system
is very important for any building because anybody
daily activities need water. Plumbing design is a fluid
mechanic problem because of the flow through pipes.
This involves precision pressure head and friction loss,
calculation and accuracy in appliance of various pipes,
fittings, pumps, etc. Based on the study and research
conducted in this paper the flow of water distribution in
this high-rise building is from tube well to ground tank
then use Transfer Pump to pump the water up to roof
tank. Water services in this building are efficient and
suitable to distribute water for the entire building. The
numbers of storage tanks are enough usage for the
people occupying the building. As only two transfer
pumps are used. It is easier to maintenance and also
reducing the cost and energy used. In this paper, the
total number of occupants, the transfer pipe size, the
distribution pipe size, the transfer pump size, the
booster pump size and the condition of before and after
using booster pump and pressure reducing valves are
calculated. Firstly, the flow rates are calculated to get
the pump sizes. The total number of occupants is
calculated by using CP-48. After calculating in each
section, the pump sizes are selected. The booster pump
is used to increase the fluid pressure from 18th floors to
16th floors, where the fluid pressure is less than one bar.
The pressure reducing valves are used to decrease the
fluid pressure from 9th to 1st floors, where the fluid
pressure is greater than three bars. The schematic
diagram of eighteen storey high rise building is shown
in Fig. 6.
ACKNOWLEDGEMENT
The author wishes to express her heartfelt thanks to
each and every one who assisted in completing this
paper.
Finally, the author deep gratitude and appreciation
go to her parents for her moral supports, patience,
understanding and encouragement.
REFERENCES
[1] Anonymous. Code of practice for water
service CP 48. Singapore Productivity and
Standards Board, Building and Industrial
Standard Council, 1989.
[2] T.Christopher Dickenson F.I .Mgt. Valves,
Piping and Pipelines Handbook.3rd ed , 1999.
[3] Anonymous. Plumbing Engineering Design
Handbook, Plumbing Components and
Equipment. U.S.A.: American Society of
Plumbings Engineers, 2008.
[4] Dr.Ali Hammoud,A.“Mechanical and
Electrical Engineering for Building
services”.Plumbing Systems Lecture Notes .
March.
[5] 2017<http://www.scribd.com
[6] Chawlwin, Mechanical and Electrical
Engineering for Building services. Domestic
water supply system, July 2017.
[7] Tayza Zaw. Plumbing & Fire Protection
Systems In Building. Yangon: Future Engineer
Generation, 2015.
[8] C.R. Mohan, and Vivek Anand. Design And
Practical Handbook On Plumbing. Delhi:
Standard Publisher Distributors, 2007.
[9] Anonymous. Committee For Quality Control
Of High-Rise Building Construction Projects
CQHP-01-Sanitary Guide lines for High-Rise
Building. Yangon: Archetype Myanmar Ltd,
2007.
[10] Anonymous. Code of practice for water
service CP 48. Standardisation Department,
Singapore, 2005.
[11] Khin Zar Ni Myint ,2020 . Plumbing and
Sanitation System for High-Rise Building. TU
(Thanlyin), Master Thesis.
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 53
Design and Structural Analysis of Impeller Blade for Centrifugal Pump
San San Yi(1), Mi Mi San(2), Yu War Myint(3) (1)Technological University (Maubin), Myanmar
(2) Technological University (Maubin), Myanmar (3) Technological University (Maubin), Myanmar
Email: sansanyi.ptu.mechanical @gmail.com
ABSTRACT: Centrifugal pump is the device for
converting of mechanical energy of the drive shaft to
hydraulic energy of the handling fluid to get it to a
required place or height by using the centrifugal force.
A centrifugal pump can be used for lifting highly
viscous liquids such as oils, muddy and sewage water,
paper pulp, sugar molasses, chemicals etc. This paper
is intended to calculate the design of backward type
impeller for centrifugal pump and structural analysis.
This pump is driven by 17 horse power electric motor
and its speed is 2929 rpm. It can be developed by the
head and pump flow rate are 34.17m and 1.083m3/min
respectively. The impeller design is based on Kyushu
method principally for centrifugal pump. In this paper,
the design of impeller for single-suction centrifugal
pump consists of mainly design and finite element
analysis. A parametric model and analysis of structural
for this design is applied statics pressure and using
Solid Works software simulation. The design data is
taken from Han Sein Thant Engineering, Pump and
Accessories Company limited, Yangon.
KEYWORDS: Centrifugal Pump Impeller Blades
Design, Finite Elements Analysis, Structural Analysis of
Impeller Blades, Aluminum Bronze, SolidWorks
Simulation.
1. INTRODUCTION Pump is machine equipment which is required
to lift from low level to high level or to flow liquid low pressure areas to high pressure areas. Centrifugal pumps are so called due to rotation in an important factor in their operation. The pump consists of associate blade rotating among a case. Water enters the impeller at the center impeller eye, flows radially outward and is discharge from the circumference into the case. During this flow through the impeller the water has received energy from the vanes resulting in an increase both in pressure and velocity. The kinetic energy of water is converted to pressure energy in the casing volute chamber [2].
A Syam Prasad, Bvvv lakshmipathi Rao, A Babji, Dr P Kumar Babu, ‘‘Static and dynamic Analysis of a Centrifugal Pump Impeller’’ Alloys are playing major role in many engineering applications. They offer outstanding mechanical properties flexibility in design capabilities, and ease of fabrication. Additional advantages include light weight and corrosion resistance, impact resistance, and excellent fatigue strength. In this paper study of static and model analysis of a centrifugal pump impeller which is made of three different alloy materials.(viz, Inconel alloy 740.Incoloy alloy 803,Warpaloy0The best material for design of
impeller is Inconel 740.Specific modulus of Inconel 740obtained in static analysis is 10% higher than other material. The nature frequency I modal analysis is 6% higher than other material. The deformation of Inconel 740 in static analysis is reduced by 12%.
S.Rajendran and Dr.K Purushothaman ‘‘Analysis of centrifugal pump impeller is using ANSYS-CFX” In this paper analysis of centrifugal pump impeller design is carried out using ANSYS-CFX. It is most common pump used in industries and domestic application. The complex internal flow in centrifugal pump impeller can predicted by ANSYS-CFX .A centrifugal action of impeller accelerates the liquid to high velocity, transferring mechanical (rotational)energy to the liquid. The flow pattern, pressure distribution in blade passage and blade loading of centrifugal pump impeller are discussed in this paper. Centrifugal pump impeller without volute casing is solved at designed mass flow rate is high. Total efficiency of pump is 30% increases.
I. PROCEDURE FOR PAPER SUBMISSION
Centrifugal pumps are classified supported the way
within in which fluid flows through the pump. The three
varieties of flow through a pump are radial flow, axial
flow, and mixed flow.
A. Radial Flow Pumps
In a radial flow pump, the liquid enters at the
middle of the vane and is directed out on the vane blades
during a direction at right angles to the pump shaft.
B. Axial Flow Pumps
In an axial flow pump, the blade pushes the liquid
in an exceedingly direction parallel to the pump shaft.
Axial flow pumps area unit generally known as
mechanical device pumps as a result of they operate
basically a similar because the mechanical device of a
ship.
C. Mixed Flow Pumps Mixed flow pumps borrow characteristics from both radial flow and axial flow pumps. As liquid flows through the vane of a mixed flow pump, the vane blades push the liquid out off from the pump shaft associated to the pump suction at an angle larger than ninety degrees.
II. THE WORKING OPERATION OF
CENTRIFUGAL PUMP Centrifugal pumps are using to raises the water or
liquid from a lower level to a higher level. Fluid enters axially through eye of the casing, is fixed within the vane blades, and is whirled tangentially and radially outward till it leaves through all circumferential
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 54
components of the vane into the diffuser a part of the casing. The working principle is that slurry enters the pump through the eye of rotating impeller which imparts a circular motion [3].
Fig 1 Centrifugal working
III. BLADES OF CENTRIFUGAL PUMPS
IMPELLER
There are three types of Blades;
1. Forward curved blade
2. Backward curved blade
3. Radial blade
Fig 2 Types of Blades
A. Specific Speed The speed in revolutions per minute at associate vane
is operated at that if reduced proportionately in size on deliver one unit of capability against one unit of total head. It is mathematically expressed as [5]
4
3H
QNsn
=
(1)
B. Input Power
η
HρgQL s=
(2)
Rated output of an electric motor
1000trη
L)aF(1rL
+=
(3)
Where,
L = input power (W)
Lr = rated output of an electric motor (kW)
Fa = allowable factor (0.10.4)
= transmission efficiency, 1 (for direct coupling)(%)
Fig. 3 Overall Efficiency Curve
C. Shaft and Hub Diameters
The diameter of the end of the main shaft can be
expressed by the equation:
3N
rLshKcd = (4)
Where,
dc = diameter of the end if main shaft (mm)
Lr = maximum input power (kW)
Ksh =0.112 (the main shaft is made of mild steel) The diameter of hub at the impeller eye is
( )
shd2.0~1.5
hD = (5)
The length of hub at the vane eye measure typically determined from
( ) shd2.0~1.0hL = (6)
The diameter of impeller eye D0 is calculated from the following equation:
2
hD
moVπ
'sQ4oD +
= (7)
Where, Do = diameter of impeller eye
Dh = diameter of hub at the impeller eye
The Velocity at the Eye Suction is
m1momo V)0.35.1(2gHKV == (8)
( ) s0.00023N0.11~0.07moK +=
(9)
Kmo = impeller eye velocity constant
Vmo = velocity at the eye suction (m/s)
g = acceleration due to gravity (m/s2)
H = head (m)
Dh = diameter of the hub (m)
D. Input Power Volumetric Efficiency
The volumetric efficiency is due to the leakage loss
which is a loss of capacity through the running
clearances between the rotation elements and the
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 55
stationary the running clearances between the rotation
elements and the stationary casing parts. The volumetric
efficiency is defined as
2/3sn
1.1241
1vη
+
= (10)
Where,
vη = volumetric efficiency (%)
Q = actual discharge at pump outlet (m3/s)
Qs’ = theoretical volume flowing through the impeller
(m3/s)
sn = specific speed (m3/s)
E. Input Power Volumetric Efficiency
The Stepanoff Chart is widely used to decide the
impeller geometry. The parameters Ku, Km1, Km2 are
obtained according to the value of ns. Then, U2, Vm1and
Vm2 are calculated by using the equations [7].
2gHKU u2 = (11)
2gHKV m1m1 = (12)
2gHKV m2m2 =
U2 = vane outlet peripheral velocity (m/s)
Vm1 = vane inlet velocity (m/s)
Vm2 = vane outlet velocity (m/s)
Ku = vane outlet peripheral velocity constant
Km1 = vane inlet velocity constant
Km2 = vane outlet velocity constant
g = acceleration due to gravity (m/s2) H = head (m)
Fig 4 Stepanoff Chart
The impeller outlet diameter, D2 is calculated by the
equation:
N π
2 U60
2D =
(12)
Where,
D2 = impeller outlet diameter (mm)
n = rotational speed (rpm)
The impeller inlet diameter D1 is calculated by the
equation:
1D
2D
2D1D = (13)
Where,
D1 = impeller inlet diameter (mm)
The following calculations are made;
2
1sD1h
D
1mD1D+
== (14)
Where,
D1s = (1.0 ~ 1.1)Do D1h = (0.7 ~ 0.9)Do
Thus, the peripheral velocity at the inlet is
60
N1D π
1U = (15)
Where,
U1 = vane inlet peripheral velocity (m/s) [8]
E. Inlet and Outlet Blade Angles of the Impeller
The blade inlet angle b1β (deg) is obtained by the
equation;
6)(0U
Vtan
U
VKtanβ
1
m11
1
m1b11
b1 +
= −−
(16)
Where,
Kb1 = velocity constant
b1β = blade inlet angle (degree)
The blade outlet angle b2β may be selected within
fairly limits. The angle b2β is usually made between 15˚
and 35˚. It is usually made slightly larger than the inlet
angle b1β to obtain a smooth and continuous passage.
F. Blade Number
The number of blades Z is based upon experience and
fixed after the vane shape has been determined. There
should be enough blades to secure proper guidance of
the liquid. The number of blades generally used is
between 5 and 8.The number of blades is decided using
the Pfleidier formula
+
−
+
2
b2β
b1β
sin
1D2D
1D2D6.5Z
(17)
(19)
Where,
Z = number of blades
D1 = impeller inlet diameter
D2 = impeller outlet diameter
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 56
G. Velocity Triangle of Centrifugal Pump
The shape of such vector diagrams is triangular and
they are called velocity triangles. It can be drawn for
any point of the flow path through the impeller, but
usually attention is focused on the entrance and
discharge triangles.
Fig 5 Inlet Velocity
Triangle
Where,
V1 = Absolute velocity at inlet
U1 = Tangential blade velocity
Vr1 = Relative velocity
Vf1 = Radial velocity
Vw1 =
Tangential velocity [8]
Fig 6 Outlet
Velocity Triangle
Where,
V2 = absolute velocity at outlet
U2 = tangential blade velocity
Vr2 = relative velocity
Vf2 = radial velocity
Vw2 = tangential velocity
The water is assumed to enter the vanes radially, so
that the absolute velocity 1α is
90 .
Vf1 = V1, Vw1 = 0
Fig 7
Inlet andOutlet Velocity Triangle
1
1b1
U
Vβtan =
(18)
From Outlet velocity diagram,
m2
f2b2
V
Vsinβ =
(19)
2tanβ
f2V
2UV w2 −=
(20) Impeller Outlet Velocity,
2
w2
2
f22 VVV += (21)
H. Inlet and Outlet Passage Width
The width at the inlet b1 and that of outlet b2 are
respectively decided based on the following equations.
Inlet passage width, [5]
=
Z1S-1πD
1πD
m1V1πD
'sQ
1b
(22)
Where,
'Qs= Flow rate through impeller
( )b1
sinβ1δ1S = (23)
( )b2sinβ2δ2S = (24)
Where,
S1 = water passage width (mm)
S2 = water passage width (mm)
1δ and
2δ are blade thicknesses near the leading
edge and trailing edge respectively. Moreover, S2 can
also be determined by the following relationship
equation [8].
ZS-πD
πD
11
1=
ZS-πD
πD
22
2 (25) (27)
Outlet passage width,
=
ZS-πD
πD
VπD
'Qb
22
2
m22
s
2
(26)
2. SPECIFICATION AND CALCULATION
RESULT OF CENTRIFUGAL PUMP IMPELLER
BLADE
Table 1. Specifications Data of Centrifugal Pump
Parameters Values
Pump head, H 34.17 m
Discharge,Q 1.083 m3/min
Rotational speed, N 2929 rpm
Density of water, ρ 1000 kg/m3
Table 2. Result of Calculation Data for Centrifugal
Pump’s Impeller
No Descriptions Symbols Result
1
Blade Thickness
Near the Leading
Edge
1 2 mm
2
Blade Thickness
Near the Trailing
Edge
2 7.42 mm
3 Inlet Blade Angle βb2 23
4 Smooth Variation in
Velocity S2 12 mm
5 Inlet Passage Width b1 20 mm
6 Outlet Passage b2 12.3 mm
V1
β1 1
U1 Vw1
Vm1
α2
β2
Vw2
U2
V2
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 57
Width
7 Hub Length Lh 40.5mm
8 Outlet Impeller
Diameter D2 180.6 mm
9 Inlet Impeller
Diameter D1 86.68 mm
10 Inner Hub Diameter D1s 95.95 mm
11 Impeller Eye
Diameter Do 91.39 mm
12 Inlet Impeller
Diameter D1m 84.98 mm
13 Outer Hub Diameter D1h 74.02 mm
14 Hub Diameter Dh 47.25 mm
18 Hub Section Shaft
Diameter dsh 27mm
3. FINITE ELEMENT ANALYSIS The finite element technique (FEM) rapidly grew
because the most helpful numerical analysis tool in many fields of engineering and technology. The main advantages are that it will be applied to arbitrary shapes in any vary of dimensions. When the FEM is applied to a specific field of analysis like stress analysis, thermal analysis, or vibration analysis it is often referred to as finite element analysis FEA. SolidWorks Premium CAD software provides the advanced capabilities. A. Mesh Types and Shapes
The shells are triangular with three vertex nodes or
three vertex and three mid-edge nodes in Fig 8(a). The
solids are tetrahedral with four vertex nodes or four
vertex and six mid-edge nodes in Fig 8(b) (c) and (d).
Solid and membrane shell elements use linear and
quadratic interpolation two or three nodes on an edge
[4].
(a) (b) (c) (d)
Fig 8 Solidworks Simulation (a) Shell Element Types
(b) (c)(d) Solid Element Types
B. Structural Component Failure
Structural components can be determined to fail by
various modes determined by buckling, deflection,
natural frequency, strain, or stress. Strain or stress
failure criteria are unit completely different depending
counting on whether or not they are unit thought of as
brittle or ductile materials. Solidworks simulation, and
most finite part systems, default to assumptive a ductile
material and show the distortional energy failure theory
that is typically referred to as the Von Mises stress, or
effective stress, even though it is actually a scalar[6].
4. SOLID MODELING USING SOLIDWORKS
The finite element model of centrifugal pump
impeller blades constructed for the dimensions used the
inner diameter is 86.68mm and outer diameter is 180.6
mm. Inlet blade angle is 18.92 ̊ and outlet blade angle is
23 ̊ with the number of blades as 7. Hub Length is 40.5
mm, hub diameter is 47.25 mm and outer hub diameter
is 74.02 mm respectively. Impeller eye diameter is
91.39 mm and inlet impeller diameter is 84.98 mm. The
impeller is made of aluminum bronze that it can be cast
easily and prevented from corrosion.
Fig 9 Modeling of Centrifugal Pump Impeller Blades
using SolidWorks Software
5. STUDY RESULT OF CENTRIFUGAL PUMP IMPELLER
BLADES
Here we are applying the pressure distribution on
the model is applied statics pressure P = ρgH. Then the
input pressure 335207.7 N/m2 applied the blade curves
and the result for bronze are described as shown in
figures and tables.
Table 3. Material Properties for Impeller Blades
Parameters Aluminum Bronze
Poisson’s Ratio (μ) 0.3
Young’s Modulus (E) 110 GPa
Thermal expansion
coefficient
1.7×10-5/K
Mass Density (ρ)
kg/m3
7400 kg/m3
Tensile Stress (t) 551.485 MPa
Yield Stress (y) 275.742 MPa
Table 4. Volumetric Properties of Impeller Blades
Document
name and
reference
Treated
As Volumetric
properties
CirPattern1
Solid
body
Mass:3.38207 kg
Volume:0.000457036
m^3
Density:7400 kg/m^3
Weight:33.1443 N
C. Study Result of Mesh Information
Fig 10 Mesh Modelling of Impeller Blades
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 58
Table 2. Result of Mesh Information
No Descriptions Symbols Result
1
Blade Thickness
Near the Leading
Edge
1 2 mm
2
Blade Thickness
Near the Trailing
Edge
2 7.42 mm
3 Inlet Blade Angle βb2 23
4 Smooth Variation in
Velocity S2 12 mm
5 Inlet Passage Width b1 20 mm
6 Outlet Passage
Width b2 12.3 mm
7 Hub Length Lh 40.5mm
8 Outlet Impeller
Diameter D2 180.6 mm
9 Inlet Impeller
Diameter D1 86.68 mm
10 Inner Hub Diameter D1s 95.95 mm
11 Impeller Eye
Diameter Do 91.39 mm
12 Inlet Impeller
Diameter D1m 84.98 mm
13 Outer Hub Diameter D1h 74.02 mm
14 Hub Diameter Dh 47.25 mm
18 Hub Section Shaft
Diameter dsh 27mm
D. Study Result of Static Von-misses Stress
Fig 11 Von-misses Stress
The Fig 11 illustrates the variation of von-misses
stress in the blades applied load. The value of maximum
stress of impeller blade using Aluminum bronze
material is found to be 22.86 MPa and minimum stress
is found to be 0.01285 MPa.
E. Study Result of Displacement
Fig 12
Displacement Result
The Fig 12 illustrates the total deformation of the
centrifugal pump impeller blade. The value of
maximum deformation of impeller blade using
Aluminum bronze material is 0.02752 mm and
minimum deformation is 0.000 mm as shown in figure.
Fig 13 Equivalent Strain Result
The Fig 13 illustrates the variation of effective
strain by using Aluminum bronze material in the
centrifugal pump impeller blades. The value of
maximum strain found to be 0.001060and minimum
strain is found to be 0.0000000008811. In this paper,
structural behaviors of impeller blade using Aluminum
bronze material is analyzed by SolidWorks.
6. CONCLUSION
The calculated impeller design has inlet diameter
86.68mm and outlet diameter 180.6mm. Inlet blade
angle 18.92 ̊ and outlet blade angle 23 ̊ with the number
of blades is 7. The inlet and outlet width are 19.1 mm
and 13 mm respectively. The impeller is made of
aluminum bronze that it can be cast easily and
prevented from corrosion. The max von misses stress
location for Aluminum bronze is at the fixed end of the
blade. Max von misses stress impact at the tip of the
blade because of acting high pressure. Aluminum
bronze is more suitable than other materials for
centrifugal pump impeller blade design. By using
aluminum in the existing blade, weight is reduced and
then, minimum deformation is formed. Their structural
analysis shows that the maximum and minimum von
misses stress, displacement and strain.
ACKNOWLEDGMENT
The author is also wishes to extend special thanks to
Dr. Kyawt Khin, Rector, Technological University
(Maubin) for her permissions of this paper. I would also
like to thank to head of Mechanical Engineering
Department Prof. Mi Mi San and all faculty members
who have timely helped to make my work successfully.
Finally, the authors are thankful to everyone who
assisted in completing this paper.
REFERENCES
[1] pa A Syam Prasad, BVVV Lakshmipathi Rao, A
Babji, Dr P Kumar Babu , “Static and Dynamic
Analysis of a Centrifugal Pump Impeller”
International Journal of Scientific & Engineering
Research, Volume 4, Issue 10, October-2013,
pp966-971
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 59
[2] Ausstin, H. Church, “Centrifugal Pump and
Blower”, 1972, John Wiley and Sons, Inc,
New York.
[3] Cho Cho khaing, Nyi Nyi, “Design of Single
Suction Centrifugal Pump and Performance
Analysis by Varying the Speed of Impeller”, July,
2018.
[4] B Karthik Matta, Kode Srividya, Inturi Prakash ,
“Static and Dynamic Response of an Impeller at
Varying Effects” IOSR Journal of Mechanical and
Civil Engineering (IOSRJMCE) e-ISSN: 2278-
1684,p-ISSN: 2320-334X, Volume 11, Issue 1 Ver.
III pp 101-106 (Jan. 2014).
[5] Kyushu Institute Technology, Training Course,
“Fluid Mechanics of Turbomachinery”, Japan,
1996.
[6] S.Rajendran and Dr. K Purushothaman “Analysis
of centrifugal pump impeller using NSYS-CFX”
International Journal of Engineering Research &
Technology (IJERT) Vol. 1 Issue 3, May - 2012 pp
1-6
[7] Stepanoff. A. J, “Centrifugal and Axial Flow
Pumps”, 1957.
[8] Touzson, J, “Centrifugal Pump Design”, John
Wiley and Sons, Inc, 2000.
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 60
NUMERICAL ANALYSIS OF CANTILEVER BEAM’S DEFLECTION FOR VARYING
LOADS BY USING SOLIDWORKS
Win Kyaw Thu(1), Khin San Htay(2), Zaw Htway(3)
(1)Technological University (Meiktila), Myanmar
(2)Technological University (Hpa-An), Myanmar (3)Technological University (Lashio), Myanmar
Email: [email protected]
ABSTRACT: The classical problem of maximum
deflection and von-mises stress analysis of a cantilever
beam, under the action of an external vertical
concentrated load at free end and a uniformly
distributed load along its length, is solved by
numerically and analytically. Among the different types
of beams, a cantilever beam has been taken and two
cross-sections are selected (I, H). The design materials
for cantilever beam are Alloy steel, Aluminium alloy
and Malleable cast iron.
The theoretical calculations are done based on the
general Euler-Bernoulli’s Beam Equation. The
numerical analysis is done on Solidworks Simulation
Software. The maximum deflection of beam which
occurs at the point of the applied load is recorded.
Comparing the theoretical results with Solidworks
simulation results, choose the material and design
which gives the minimum deflection and the maximum
yield strength. From all the numerical results and
analytical results, it can be concluded that I-section
beam with alloy steel is the best to do for cantilever
beam than any other materials and cross-sections in this
paper. Although H-section beam has higher yield
strength than I-section beam, it has more deflection than
I-section. This is the main reason of H-section beam is
not used as a cantilever beam. Therefore I-section is the
best design for cantilever beam as it deflection is
minimum. As alloy steel and malleable cast iron have
nearly the same deflection, therefore malleable cast iron
can be used as a cantilever beam instead of alloy steel in
order to save the economic costs.
KEYWORDS: Cantilever beam, Simply Supported Beam,
Overhanging Beam, Maximum deflection, Moment of
Inertia, Varying Load Analysis
1. INTRODUCTION
Basically in general terms, a cantilever beam is a
beam which is fixed at one end. In this paper, behavior
of beams and solid elements have been analyzed on the
basis of deflection and von-misses stress occurred on
cantilever beam due to various types of load i.e point load at free end and uniformly distributed load over the
whole beam. These loads are applied on I-section, H-
section cantilever beams. The materials used for the
beams are Alloy steel, Aluminium alloy and Malleable
cast iron. In this paper, while the beam gets deflected under
the loads, bending moment occurs in the same plane
due to which stresses are developed. Here the deflection
of the beam element is calculated by using Euler-
Bernoulli’s beam equation. Solidworks software has
been used to do the computational analysis. Cantilevers
are widely found in constructions, notably in cantilever
bridges and balconies [3,4,8].
A . CANTILEVER BEAM
A cantilever beam is a beam supported on only one
end. The beam transfers the load to the support where it
has managed to the moment of force and shear stress.
Moment of force is the tendency of a force to twist or
rotate an object. Shear stress is defined as a stress which
is applied parallel to the face of a material.
. In other words, the beam bears a specific weight
on its open end as a result of the support on its closed
end, in addition to not breaking down as a result of the
shear stress the weight would generate on the beam’s
structure. Cantilever construction allows for
overhanging structures without external bracing pillars
[12].
Figure 1.Cantilever Beam Source: [12]
2. EULER BERNOULLI’S BEAM EQUATION
Euler Bernoulli beam theory, also known as
engineer’s beam theory or classical beam theory, is a
simplification of the linear theory of elasticity which
provides a means of calculating the load-carrying and
deflection characteristics of beams. Euler Bernoulli’s
equation describes the relationship between the beam’s
deflection and applied load [11].
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 61
Maximum Deflection for Point Load at Free End,
maxδ =
3W L
3 E I
Where,
W = Point load (N)
L = Length of the beam (mm)
E = Young’s modulus (N/mm2)
I = Moment of inertia (N/mm4)
maxδ = Maximum deflection (mm)
Maximum Deflection for Uniformly Distributed
Load over the whole beam,
maxδ =
3ω L
8 E I
ω = W × L
Where,
ω = Uniformly distributed load (N/mm)
L = Length of the beam (mm)
E = Young’s modulus (N/mm2)
I = Moment of inertia (4mm )
maxδ = Maximum deflection (mm)
Cantilever Bending Method
E =
3
3
4×m×g×L
δ×w×t (3.5)
Where,
E = Young’s modulus (N/mm2)
m = Applied load (g)
L = Length of the beam (mm)
w = Width of the beam (mm)
g = Acceleration due to gravity (m/s2)
t = Thickness of the beam (mm)
δ = Deflection (mm)
Moment of Inertia for I-Section Beam
I =
3 3
2 1wh -(w-t )×(h-t )
12
Where,
w = Width of the beam (mm)
h = Height of the beam (mm)
1t = Thickness of flange (mm)
2t = Thickness of web (mm)
I = Moment of inertia (4mm )
Moment of Inertia for H-section Beam
I =
3 3
1 1 22(t ×h )+(w-2t )×t
12 Where,
w = Width of the beam (mm)
h = Height of the beam (mm)
1t = Thickness of flange (mm)
2t = Thickness of web (mm)
I = Moment of inertia (4mm )
Table 1. Dimensions of I-Beam, H-Beam
Dimensions I Beam H Beam
w 100mm 200mm
h 200mm 100mm
t1 8mm 8mm
t2 5.5mm 5.5mm
L 3000mm 3000mm
W 1000N 1000N
ω 1 N/mm 1 N/mm
Table 2. Mechanical Properties of Alloy Steel,
Malleable Cast Iron and Aluminium Alloy [11]
Mechanical
Properties
Alloy Steel Mallesble
Cast Iron
Aluminium
Elastic
Modulus
2.1×1011
N/m2
1.9×1011
N/m2
7.4×1010
N/m2
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 62
(a)Deflection of I-Beam on Alloy Steel by Point Load
(b)Deflection of I-Beam on Alloy Steel by Uniformly
Distributed Load
(c)Deflection of I-Beam on Malleable Cast Iron by
Point Load
(d)Deflection of I-Beam on Malleable Cast Iron by
Uniformly Distributed Load
(e)Deflection of I-Beam on Aluminium Alloy by Point
Load
(f)Deflection of I-Beam on Aluminium Alloy by
Uniformly Distributed Load
(g)Yield Strength of I-Beam on Alloy Steel by Point
Load
(h)Yield Strength of I-Beam on Alloy Steel by
Uniformly Distributed Load
(i)Yield Strength of I-Beam on Malleable Cast Iron by
Point Load
(j)Yield Strength of I-Beam on Malleable Cast Iron by
Uniformly Distributed Load
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 63
(k)Yield Strength of I-Beam on Aluminium Alloy by
Point Load
(l)Yield Strength of I-Beam onAluminium Alloy by
Uniformly Distributed Load
(a)Deflection of H-Beam on Alloy Steel by Point Load
(b)Deflection of H-Beam on Alloy Steel by Uniformly
Distributed Load
(c)Deflection of H-beam on Malleable Cast Iron by
Point Load
(d)Deflection of H-Beam on Malleable Cast Iron by
Uniformly Distributed Load
(e)Deflection of H-Beam on Aluminium Alloy by Point
Load
(f)Deflection of H-Beam on Aluminium Alloy by
Uniformly Distributed Load
(g)Yield Strength of H-Beam on Alloy Steel by Point
Load
(h)Yield Strength of H-Beam on Alloy Steel by
Uniformly Distributed Load
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 64
(i)Yield Strength of H-Beam on Malleable Cast Iron by
Point Load
(j)Yield Strength of H-Beam on Malleable Cast Iron by
Uniformly Distributed Load
(k)Yield Strength of H-Beam on Aluminium Alloy by
Point Load
(l)Yield Strength of H-Beam on Aluminium Alloy by
Uniformly Distributed Load
4. RESUIT AND DISCUSSION
Table 3.Maximum Deflection of Alloy Steel, Malleable
Cast Iron and Aluminium Alloy by Point Load and
Uniformly Distributed Load on I-Beam
Materials
Young’s
Modulus
(N/mm2)
Maximum Deflection
( mm )
Point
Load
Uniformly
Distributed
Load
Alloy Steel 2.1×105 2.43 2.74
Malleable Cast
Iron 1.9×105 2.69 3.03
Aluminium
Alloy 7.4×104 6.91 7.8
Table 4.Maximum Deflection of Alloy Steel, Malleable
Cast Iron and Aluminium Alloy by Point Load and
Uniformly Distributed Load on H-Beam
Materials
Young’s
Modulus
(2N mm )
Maximum Deflection (
mm )
Point
Load
Uniformly
Distributed
Load
Alloy Steel 2.1×105 32 36
Malleable
Cast Iron 1.9×105 35.3 39.8
Aluminium
Alloy 7.4×104 90.7 102.1
Table 5. Comparison of Deflection and Von-mises
Stress Results
Res
ult
s
Cro
ss-S
ecti
on
Alloy Steel Malleable Cast
Iron
Aluminium
Alloy
P.L U.D.
L
P.L U.D.
L
P.L U.D.
L
Def
lect
ion (
mm
) I 2.4
3 2.74 2.69 3.03 6.91 7.8
H
32 36 35.3 39.8 90.7 102.1
Von-m
ises
Str
ess
(MN
/m2)
I 17.
04 25.55 17.04 25.55 17.04 25.55
H
112
.3 168.4 112.3 168.4 112.3 168.4
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 65
In this paper, the maximum deflection of alloy steel
is 2.43 mm, the maximum deflection of malleable cast
iron is 2.69 mm and the maximum deflection of
aluminum alloy is 6.91 mm for I-section beam. The
maximum deflection of alloy steel is 32 mm, the
maximum deflection of malleable cast iron is 35.3 mm
and the maximum deflection of aluminum alloy is 90.7
mm for H-section beam. From all the numerically and
analytically results, it can be concluded that I-section
beam with alloy steel is the best to do for cantilever
beam than any other materials and cross-sections in this
paper. The yield strength of H-section is 112.3 MN/m2
and I-section is 17.04 MN/m2. Although H-section
beam has higher yield strength than I-section beam, it
has more deflection than I-section. This is the main
reason of H-section beam is not used as a cantilever
beam. Therefore, I-section is the best design for
cantilever beam as its deflection is minimum. As alloy
steel and malleable cast iron have nearly the same
deflection, therefore malleable cast iron can be used as
a cantilever beam instead of alloy steel in order to save
the economic costs.
5. CONCLUSIONS
In this study the deflection of I- beam and H-Beam
are compared with analytical and numerical analysis.
The deflection of I-section beam with alloy steel is 2.43
mm and its has the yield strenght of 17.04 MN/m2.
Therefore, I-section is the best design for cantilever
beam as its deflection is miniumm.
ACKNOWLEDGEMENT
I would like to thank my thanks the reviewers for
their valuable comments and suggestions and would
also like to thank all teachers for their valuable support
and encouragement.
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and Stress Analysis Of A Beam On Different
Elements Using Ansys APDL, (IJMET)
Volume 5, Issue 6, June (2014), pp 70-79.
[2] Eduardo Valencia Morales, Alloy Steel
Properties and Use First-Principles Quantum
Mechanical Approach to Stainless Steel
Alloys.
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of Stress and Deflection of Cantilever Beam
and its Validation Using ANSYS, Vol. 6, Issue
1, (Part - 4) January 2016, pp.119-126.
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A.Gophichand, A.Krishna Priya,
Determination of Stress and Deflection of
Cantilever Beam for Various Cross-Sections.
[5] Yousif K. Yousif, Experimental & Theoretical
Analysis of Composite (Polyester & Silicon-
Carbide) Cantilever Beam, Al-Khwarizmi
Engineering Journal, Vol. 8, No. 3, PP 12-
23(2012).
[6] Tarsicio Belendez, Cristian Neipp and Augusto
Belendez, Numerical and Experimental
Analysis of a Cantilever Beam: a Laboratory
Project to Introduce Geometric Nonlinearity in
Mechanics of Materials, Int.J.Engng Ed,
Vol.19, No.6, pp.885-892, 2003.
[7] A.Kimiacifar, N.Tolou, A.Baran and
J.L.Herder, Large deflection analysis of
cantilever beam under end point and
distributed loads, Journal of the Chinese
Institute of Engineers, 2014 Vol. 37, No. 4,
438–445.
[8] Shang-Hsi Tsai and Heng-Chuan Kan, The
exact solution of the load-deflection model of a
uniformly loaded rectangular cross-section
cantilever beam, J. Phys. D: Appl. Phys. 41
(2008) 095502 (6pp).
[9] Solidworks Software (2016)
[10] J.R. Davis, p351-416, Aluminium and
Aluminium Alloys.
[11] Strength of Materials (Second Edition), S S
Rattan.
[12] https://www.quora.com
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 66
Design and Analysis of Piston for Four Stroke Single Cylinder Engine by Using Different
Materials
Arkar Htun (1), Zin Mar Nwe (2), Thin Thin Oo (3)
(1) Department of Mechanical Engineering, TU (Magway), Myanmar
(2) Department of Mechanical Engineering , TU (Magway), Myanmar
(3) Department of Mechanical Engineering, TU (Magway), Myanmar
Email; [email protected]
ABSTRACT: Piston is the major part of an internal
combustion engine, which converts the chemical energy
of the fuel into the mechanical energy obtained at the
crankshaft through the connecting rod. An internal
combustion engine is acted upon by the pressure of the
expanding combustion gases in the combustion
chamber space at the top of the cylinder. This force then
acts downwards through the connecting rod and onto
the crankshaft. The piston design is for 150cc 4-stroke
petrol engine in which the various dimensions of piston
is calculated by analytical method considering
maximum pressure condition and the material
Aluminum alloy 4032-T6 is used. In this paper of the
piston consists of mainly design and analysis. A
parametric model and analysis of piston is using
Solidworks 2019 software. The existing one in the
design and analyzed the different material Aluminum
alloy 2014-T6. Then the analysis becomes completed
on the different parameters (temperature, stress,
deformation) and easily analysis the result. After the
analysis of the different material piston it analyzed that
the Aluminum alloy 4032-T6 is suitable for I.C Engine
piston.
KEYWORDS: Design of Piston, Solidworks, Model of
Piston, Analysis thermal stress, Aluminum alloy 4032-
T6, Aluminum alloy 2014-T6.
1. INTRODUCTION
Engine pistons are one of the most complex
components among all automotive or other industry
field components. The engine can be called the heart of
a car and the piston may be considered the most
important part of an engine. The purpose of the piston is
to transfer the energy to crankshaft via connecting rod.
The piston ring is used to provide seal between the
cylinder and piston.
The main function of the piston is to transfer force from
gas in the cylinder to the crank shaft through connecting
rod. It is very important to calculate temperature
distribution on the piston in order to control thermal
stresses and deformation in working condition.
It is very essential to check out or analyze the stress
distribution, temperature distribution, heat transfer,
thermal load, mechanical load in order to minimize the
stress and different loads on working condition of the
piston.
Fig 1. Piston components for I.C. engine [1]
2. PISTON MATERIALS
The pistons are made of different materials such as
carbon steel, cast iron, aluminum alloys etc. Since the
aluminum alloys used for pistons have high heat
conductivity, therefore, these pistons ensure high rate of
heat transfer and thus keeps down the maximum
temperature difference between the centre and edges of
the piston head or crown. For aluminum alloy pistons,
TC is about 260°C to 290°C and Te is about 185°C to
215°C, but they lose their strength (about 50%) at
temperatures above 325°C. [6]
3. THEORETICAL BACKGROUND
3.1 Design Consideration for Piston
In designing a piston for I.C engine, the following
points should be taken into consideration:
1. It should have enormous strength to withstand the
high gas pressure and inertia forces.
2. It should have minimum mass to minimize the
inertia force.
3. It should form an effective gas and oil sealing of
the cylinder.
4. It should provide sufficient bearing area to prevent
undue wear.
5. It should disperse the heat of combustion quickly
to the cylinder walls.
6. It should have high speed reciprocation without
noise.
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 67
7. It should be of sufficient rigid construction to
withstand thermal and mechanical distortion.
8. It should have sufficient support for the piston
pin.[6]
3.2 Design Procedure
The design procedure of piston consists of the
following parameters:
1. Maximum Gas Pressure (P)
2. Thickness of piston head (th)
3. Heat flows through the piston head (H)
4. Radial thickness of the ring (t1 )
5. Axial thickness of the ring (t2)
6. Width of the top land (b1 )
7. Width of other ring lands (b2)
8. Maximum Thickness of Barrel (t3 )
9. Piston wall thickness towards the open end
10. Piston pin diameter (do)
3.3. Maximum Gas Pressure
The maximum gas pressure (P) can be calculated
using the following equation,
= I.P
BP (1)
I.P= Pb ×4
2πD
× L × 2
N (2)
P=10Pb (3)
Its range 9 to 10 times of Pb.
Where,
η = mechanical efficiency
BP = brake power of the engine per cylinder (kW)
IP = indicated power produced inside the cylinder (kW)
N = engine speed (rpm)
L = length of stroke (mm)
D = cylinder diameter (mm)
Pb = brake mean effective pressure (MPa)
P = maximum gas pressure or explosion pressure (MPa)
3.4 Thickness of Piston Head
The piston thickness of piston head calculated
using the following Grashoff’s formula.[1]
th =
t σ
PD
16
23
(4)
Where,
P = maximum gas pressure (MPa)
D = cylinder bore/outside diameter of the piston (mm).
1 = permissible tensile stress for the material of the
piston (MPa) and th = thickness of piston head (mm)
3.5 Heat Flow through the Piston Head
The heat flow through the piston head is
calculated using the equation,
H= C × HCV × M × BP (5)
th = )eTc(TK.
H
−5612 (6)
Where,
H = heat flow through the piston head (kJ/kg hr)
C=constant heat supplied to engine
HCV= higher calorific value of petrol (kJ/kg)
M = mass of fuel used per cycle( kg/BP s)
k = thermal conductivity of material (W/mK)
Tc = temperature at centre of piston head (°C)
Te = temperature at edges of piston head in (°C)
3.6 Radial Thickness of Ring
Ring dimension from the front face touching the
cylinder wall to the back or inside face of the ring.
t1 = D ×
tσ
wP3 (7)
Where,
D = cylinder bore (mm)
Pw = pressure of gas on the cylinder wall(MPa)
σt = allowable bending tensile stress (MPa)
3.7 Axial Thickness of Ring
The thickness of the rings may be taken as
t2 = 0.7t1 to t1 (8)
Where,
t2 = axial thickness of ring (mm)
t1 = radial thickness of ring (mm) [3]
3.8 Width of the Top Land
The width of the top land varies from
b1 = tH to 1.2tH (9)
Where,
b1 = width of the top land (mm)
tH = thickness of piston head (mm) [3]
3.9 With of the other Lands
Width of other ring lands varies from be
calculation from the equation (7).
b2 = 0.75t2 to t2 (10)
Where,
b2 = width of other ring lands (mm)
t2 = thickness of the rings (mm) [10]
3.10 Maximum Thickness of Barrel
t3 = 0.03D + b + 4.5 (11)
Where,
t3 = maximum thickness of barrel (mm)
b = radial depth of piston ring groove.) [3]
3.11 Piston Wall Thickness towards the Open End
t4 = 0.25t3 to 0.35t3 (12)
Where,
t4 = piston wall thickness towards the open end (mm)
3.12 Piston Pin Diameter
do = 0.28 D to 0.38 D (13)
Where,
do = piston pin diameter (mm) [3]
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4. PISTON DESIGN CALCULATIONS
The design calculations for the piston is considered
under the maximum pressure condition over the piston.
Table 1. Engine Specifications [4]
Parameters Values
Engine Type Four stroke, Petrol Engine
Induction Air cooled type
No. of cylinder single cylinder
Bore 50 mm
Stroke length 70 mm
Speed 4250 rpm
Brake power 6.5 kW
Compression ratio 8.4
Table 2. Piston Design Calculation Results
Parameters Values
Maximum Gas Pressure 1.7 MPa
Thickness of Piston Head 4.6 mm
Heat Flow through the Piston Head 3.38 mm
Radial Thickness of Ring 1.6 mm
Radial Thickness of Ring 1.12 to 1.6 mm
Width of the Top Land 4.6 to 5.52 mm
Width of the Other Land 0.84 to 3 mm
Maximum Thickness of Barrel 8.00 mm
Piston Wall Thickness Towards 2.0 to 2.8 mm
Piston Pin Diameter 14 to 19 mm
Table 3. Materials Properties of Piston [7]
Parameters Al alloy
4032-T6
Al alloy
2014-T6
Poisson’s Ratio (μ) 0.34 0.33
Young’s Modulus (E) 79 GPa 104.8 GPa
Thermal
Conductivity (k)
138 W/mK 155 W/mK
Thermal expansion
coefficient ()
1.94×10-5/K 2.3×10-5/K
Mass Density (ρ)
kg/m3
2680 kg/m3 2800 kg/m3
Tensile Stress (t) 380 MPa 47 MPa
Yield Stress (y) 315 MPa 415 MPa
5. PISTON MODELING
The design of the piston based on the analytical
calculations is modelled in the software solidworks and
material assigned for this design is of Aluminum 4032 –
T6 material. Drawing and 3D Modelling of the piston is
done using Solidworks software. Design calculations
are done mathematically using various formulae for
finding the different dimensions of the piston. [3]
5.1 Model Information of Aliminum Alloy 2014-T6
using Solidworks Software
Fig 2. Piston Modeling Solid Body Mass : 0.149637 kg Volume : 5.58347e-05 m^3
Density : 2680 kg/m^3
Weight : 1.46644 N
6. ANALYSIS THERMAL STRESS for PISTON
The static and thermal analysis for the piston was
done by finite elements method using solidworks
software. In present examination work we have used
FEA for the Thermal and Structural analysis of piston.
Stress analysis of the piston model has been
performed to obtain the value and parameters at which
the piston would be damaged. Solid works software is
used to prepare the piston modelling and the finite
element analysis. By using this softwar, simulation
results are obtained for two different material. [8]
6.1 Study Result of Piston Head Applied
Temperature 500 C
Here, the temperature distribution on the piston
head is applied 500℃. The result for Aluminum alloy
4032-T6 are described.
Fig 3. Mesh Modelling of Aluminum Alloy 4032-T6
Piston Head applied Temperature 500°C
Table 3. Result of Mesh Information Study of
Aluminum Alloy 4032-T6 Piston Head Applied Temp
500 C
Mesh type Solid Mesh
Mesher Used: Standard
mesh
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Jacobian points 4 Points
Element Size 3.82334 mm
Tolerance 0.191167 mm
Mesh Quality Plot High
Total Nodes 17753
Total Elements 9766
Maximum Aspect Ratio 17.251
% of elements with Aspect Ratio < 3 93.3
% of elements with Aspect Ratio > 10 0.236
Time to complete mesh(hh;mm;ss): 00:00:02
Fig 4. Von-misses Stress Result 1
The figure. 4 illustrates the variation of von-misses
stress in the piston head. The value of maximum stress
found to be 1043 MPa. The value of minimum stress is
found to be 0.0278 MPa.
Fig 5. Displacement Result 1
The figure 5 illustrates the total deformation of the
piston. The value of maximum deformation is 0.1304
mm .The value of minimum deformation 000 mm,
which is occurred at the center of piston head as shown
in figure.
Fig 6. Equivalent Strain Result 1
The figure 6 illustrates the variation of equivalent
strain in the piston. The value of maximum strain found
to be 0.008026. The value of minimum strain is found
to be 0.00000001656.
6.2 Study Result of Piston Wall Applied
Temperature 300 C
The temperature distribution on the piston wall is
applied 300℃. The result for Aluminum alloy 4032-T6
are described as shown in figures.
Fig 7. Von-misses Stress Result 2
The figure 7 illustrates the variation of von-misses
stress in the piston wall. The value of maximum stress
found to be 516.2 MPa. The value of minimum stress is
found to be 0.4954 MPa.
Fig 8. Displacement Result 2
The figure 8 illustrates the total deformation of the
piston. The value of maximum deformation is 0.01792
mm. The value of minimum deformation 0.000000 mm
at the piston wall as shown in figure.
Fig 9. Equivalent Strain Result 2
The figure 9 illustrates the variation of equivalent
strain in the piston. The value of maximum strain found
to be 0.003425. The value of minimum strain is found
to be 0.000003866.
6.3 Study Result of Aluminum Alloy 2014-T6 Piston
Head Applied Temperature 500°C
The temperature distribution on the piston head is
applied 500℃. The result for Aluminum alloy 2014-T6
are described as shown in figures and tables.
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TULSOJRI September, 2020 70
Fig10. Mesh Modelling of Aluminum Alloy 2014-T6
Piston Head Applied Temperature 500°C
Table 4. Result of Mesh Study Aluminum alloy 2014-
T6 Piston Head Applied 500 C
Mesh type Solid Mesh
Mesher Used: Curvature-based
mesh
Jacobian points 4 Points
Maximum Element Size 6.97759 mm
Minimum Element Size 1.39552 mm
Mesh Quality Plot High
Total Nodes 6037
Total Elements 3039
Maximum Aspect Ratio 25.3
% of elements with Aspect
Ratio < 3
59.4
% of elements with Aspect
Ratio > 10
0.79
Time to complete
mesh(hh;mm;ss):
00:00:02
Fig 11. Von-misses Stress Result 3
The figure 11 illustrates the variation of von-
misses stress in the piston head. The value of maximum
stress found to be 1064 MPa. The value of minimum
stress is found to be 0.02149 MPa.
Fig 12. Displacement Result 3
The figure 12 illustrates the total deformation
of the piston. The value of maximum deformation is
0.1498 mm. The value of minimum deformation
0.00000 mm, which is occurred at the center of piston
head as shown in figure.
Fig 13. Equivalent Strain Result 3
The figure 13 illustrates the variation of
equivalent strain in the piston. The value of maximum
strain found to be 0.008892. The value of minimum
strain is found to be 0.00000008881.
6.4 Study Result of Aluminum alloy 2014-T6 Piston
Wall Applied Temperature 300°C
Fig 14. Von-misses Stress Result 4
The figure 14 illustrates the variation of von-misses
stress in the piston wall. The value of maximum stress
found to be 544.6 MPa. The value of minimum stress is
found to be 0.314 MPa.
Fig 15. Displacement Result 4
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The figure 15 illustrates the total deformation of
the piston. The value of maximum deformation is
0.1837mm. The value of minimum deformation
0.000000 mm occurred at the piston wall as shown in
figure.
Fig 16. Equivalent Strain Result 4
The figure 16 illustrates the variation of equivalent
strain in the piston. The value of maximum strain found
to be 0.003633. The value of minimum strain is found
to be 0.000003217.
7. COMPARATIVE PERFORMANCE RESULT
TABLE 5. TWO DIFFERENT ALUMINUM ALLOY AT
PISTON HEAD AT TEMPERATURE 500C
Parameters Al alloy
4032-T6
Al alloy
2014-T6
Von-misses stress
(MPa)
1043
0.002078
1064
0.02149
Total Deformation
(mm)
0.1304
0000
0.1498
0.000
Equivalent strain
(MPa)
0.008026
0.00000001656
0.008892
0.0000008881
TABLE 6. TWO DIFFERENT ALUMINUM ALLOY AT
PISTON WALL AT TEMPERATURE 300C
Parameters Al alloy
4032-T6
Al alloy
2014-T6
Von-misses stress
(MPa)
516.2
0.4954
544.6
0.314
Total Deformation
(mm)
0.01792
0000
0.1837
0.000
Equivalent strain
(MPa)
0.003425
0.000003866
0.003633
0.000003217
8. CONCLUSION
After doing comparative analysis result through
this work, it is concluded that stress occurred by using
Al-alloy 4032-T6 is lower than the permissible stress
value, so that is best material for piston. The structural
analysis shows that the maximum von Mises Stress
occurs at Aluminum Alloy 2014-T6 at piston head at
displacement 0.1498. Maximum temperature is found at
the center of the top surface of the piston head.
Depending on the thermal conductivity of the materials,
heat transfer rate is found maximum in Al alloy piston.
For the given loading conditions, Al alloy 4032-T6
piston is found most suitable. But when the loading
pattern changes, other materials may be considered.
ACKNOWLEDGEMENT
The authors wish to express their deep gratitude to
Dr. Tin San, Rector, Technological University (Lashio)
for his kindly advice and permission to carry out this
paper. Furthermore, special thanks are extended to the
Technological University (Magway) for their
deliberations and disclosures on the paper.
REFERENCES
[1] Deovrat Vibhandik, Ameya Pradhan, Sampada
Mhaskar, Nikita Sukthankar, Atul Dhale, (2014) ,
Design Analysis and Optimization of Piston and
Determination of its Thermal Stresses Using CAE
Tools, 3(5), pp.273-277.
[2] Gantla Shashidhar Reddy and N. Amara
NageswaraRao, (2013), Modeling and analysis of
diesel engine piston, International journal of
Mathematics and Engineering, 2, pp. 199 – 202.
[3] Jan Filipczyk, Zbigniew Stanik, (2012), Piston
damages-case studies and possibilities of early
detection, Journal of KONES Powertrain and
Transport, 19(4), pp. 179-184.
[4] Lokesh Singh, Suneer Singh Rawat, Taufeeque
Hasan, Upendra Kumar, (2015), Finite element
analysis of piston in ansys, 02, pp. 239-241.
[5] M. T. V and D. S. P. M, "Structural and Thermal
Analysis of Rotor Disc of Disc Brake," International
Journal of Innovative Research in Science,
Engineering and Technology, vol. 2, no. 12, pp.
7741-7749, 2013.
[6] Swati S. Chougule, Vinayak H. Khatawate, (2013),
Piston Strength Analysis Using FEM,International
Journal of Engineering Research and Applications, 3,
pp.124-126.
[7] Vaibhav V. Mukkawar, Abhishek D. Bangale,
Nititn D. Bhusale, Ganesh M. Surve, (2015), Design
analysis and optimization of piston using CAE tools,
International Conference, Pune, India.
[8] S. Srikanth Reddy, Dr. B. Sudheer Prem Kumar,
(2013), Thermal Analysis and Optimization of I.C.
Engine Piston Using Finite Element Method,
International Journal of Innovative Research in
Science, Engineering and Technology, 2, pp. 319-
323.
[9] Vaibhav V. Mukkawar, Abhishek D. Bangale,
Nititn D. Bhusale, Ganesh M. Surve, (2015), Design
analysis and optimization of piston using CAE tools,
International Conference, Pune, India.
[10] Vivek Zolekar, Dr. L. N. Wankhade, (2013),
Finite Element Analysis and Optimization of I.C.
Engine Piston Using RADIOSS and Optistruct, Altair
technology conference.
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 72
Design Calculation of a Double Suction Centrifugal Pump (Impeller) by Using MATLAB
Dr Aung Kyaw Soe(1) (1)Technological University (Toungoo), Myanmar
Email: [email protected] ; [email protected] ABSTRACT: In this paper, the basic theory and
detailed design calculation of double suction centrifugal
pump are presented. A double suction centrifugal pump
is chosen to carry out design calculation because it can
be widely used in the field of drainage system,
irrigation work and agriculture.
In this study, the impeller of the double suction
centrifugal pump is designed for delivering the water
flow rate of 5.05 m3/min and 54 m head. The rotational
speed of driving shaft is 2980 rpm. The outer and inner
diameters of designed impeller are 0.220 m (220 mm)
and 0.108 m (108 mm) respectively. Calculated number
of blades is eight and the calculated specific speed is
238. All feasible losses are neglected in design
calculation. Pump efficiency is 77.13 % in this design.
And, design calculation is done by using MATLAB
programming. So, design calculation for different input
data such as head, flow rate and rotational speed can be
carried out with the aid of the MATLAB program.
KEYWORDS: centrifugal, design, impeller, double,
MATLAB
1. INTRODUCTION
In general, pumps are devices which impart
energy to a flow of liquid. Although there are different
types of pumps based on the flow direction, blade
designs, and so on, centrifugal pumps are in the
majority of those used in cleaning systems. Centrifugal
pumps are simple, efficient, reliable, relatively
inexpensive, and easily meet the needs of most cleaning
system requirements including spraying, overflow
sparging, filtration, turbulation and the basic function of
moving liquids from one place to another using
pressure. A centrifugal pump uses a combination of
angular velocity and centrifugal force to pump
liquids. The pump consists of a circular pump housing
which is usually made up of metals, (stain steels etc.)
solid plastic, or ceramics. The outlet extends
tangentially from the diameter of the pump housing.
Inside the pump housing there is a rotating component
an “impeller” which rotates perpendicular to the central
axis and is driven by a shaft secured to its center of
rotation. The shaft, powered by an electric motor,
enters the pump housing through a liquid tight seal
which prevents leaking. Liquid entering the pump
through the inlet is swirled in a circular motion and
displaced from the rotation center of the impeller by
centrifugal force. The combination of the swirling
action (angular velocity) and centrifugal force (radial
velocity) pushes the liquid out of the pump through the
outlet [9]. According to the design and principal of
operation, pumps may be classified into two general
categories: rotodynamic pressure pumps and positive
displacement pumps [5].
The centrifugal pumps may be either single or
multi-stage. In addition, the single-stage centrifugal
pumps may be either single-suction or double-suction.
In single-suction centrifugal pumps, the water enters on
one side of the casing and impeller. The most common
type of multi-suction design in centrifugal pump
engineering is a double-suction pump whose impeller
pair is arranged back to back on the pump shaft. A
double-suction pump with impellers arranged in parallel
can be used to increase the flow rate at a constant head.
Double-suction pumps are employed when the flow rate
required of a centrifugal pump becomes too large for
the inlet cross-sections of one impeller or when the flow
velocity in the inlet cross-section of the first impeller
has to be reduced to prevent cavitation [10]. Figure 1
shows main components of centrifugal pump with
double suction impeller.
Fig.1 Main Components of Centrifugal Pump with
Double Suction Impeller [2]
2. LITERATURE REVIEW
In 2018, design and flow simulation for a
centrifugal pump with double-suction impeller are
carried out with the aid of SolidWorks Flow Simulation
by Eugen-Vlad Năstase. In 2013, computational flow
analysis through a double-suction pump impeller of
centrifugal pump was carried out by Deepak Kumar
Kalyan in India. A double suction centrifugal pump
impeller was modeled and analyzed with the aid of
CFD commercial software in this research. In 2016,
Nwe Ni Win performed design and flow analysis of
double suction centrifugal pump impeller in Myanmar.
In this research, the double-suction impeller blade 3D
model was generated with SolidWorks software and
analyze in flow simulation of the impeller. In 2017,
CFD Analysis of double-suction centrifugal pump with
double volute is carried out by Pranav Vyavahare. In
this research, Impeller vane profile is generated by
tangent arc method and CFD analysis is performed for
1st stage of vertical pump out of 15 stages. Moreover,
head developed by this impeller is calculated and
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 73
compared with the required value by using ANSYS-
CFX. In 2009, design and calculation of multi-stage
centrifugal pump impeller was carried out by Aung
Kyaw Soe in Myanmar. In this research, design
calculation of impeller was performed by using
MATLAB programming.
2.1 Specification
The following specifications are used to carry out
the design calculation of single stage double-suction
centrifugal pump (impeller) for fresh water.
Flow Rate, Q=5.05 m3/min
Head, H=54 m
Speed, N=2980 rpm
Density ρ=1000 kg/m3 (for water)
Gravitational Acceleration = 9.81 m2/sec
2.2 Design Theory of Centrifugal Pump
Specific Speed, ns =𝑁𝑄𝑠
1/2
𝐻3/4
(1)
where, ns = specific speed
Q = discharge in (m3/s)
N = pump speed in rpm
H = head per stage in m
Input Power, L=gQsH/ (2)
Rated output of an electric motor Lr(kW) is decided
from the following equation.
Lr=(1+𝑓𝑎)×𝐿
𝜂𝑡𝑟
(3)
Where, fa is the allowance factor and 0.1~0.4 for an
electric motor and larger than 0.2 for engines. tr is the
transmission efficiency, and 1.0 for the direct
coupling, and 0.9~0.95 for the belt drive.
Hub and Shaft Diameters
The diameter of the end main shaft can be calculated by
the equation:
dc=Ksh √Lr
N
3 (4)
Where, Ksh=permissible shear stress factor
dc=diameter of the end of main shaft in m
Lr=output power of an electric motor in KW
The shaft diameter at the hub section should be
selected so as to satisfy dsh>dc. The diameter at the hub,
dh is made from 1.5 to 2 larger than the shaft diameter,
depending on the shaft size. It is usually decided from
the equation:
dh=(1.5~2.0)dsh (5)
The length of the hub, lh at the impeller is also
calculated by the equation:
lh=(1.0~2.0)dsh>dh (6)
Volumetric efficiency, 𝜂𝑣
=1
{1+(1.124
𝑛𝑠2/3)}
(7)
Flow Rate of impeller eye, Qs' = 𝑄𝑠
𝜂𝑣
(8)
The diameter of impeller eye, Do=√4𝑄𝑠′
2𝜋𝑉𝑚𝑜+ 𝑑2
ℎ (9)
Where, Velocity of impeller eye, Vmo =Kmo√2𝑔𝐻
Velocity Coefficient of impeller eye,
Kmo= (0.07~0.11)+0.00023 x ns (10)
The Stepanoff Chart is widely used to decide the
impeller geometry, if the blade outlet angle 2 near 22.5
degree is selected. The parameter Ku (speed constant),
Km1, Km2 and D1/D2 are obtained, since ns is given.
U2= Ku√2𝑔𝐻 (11)
Vm2=Km2√2𝑔𝐻 (12)
Vm1=Km1√2𝑔𝐻 (13)
Where, Vm1 = Meridional velocity at impeller profile
entrance ( m/s)
Vm2 = Meridional velocity at impeller profile outlet m/s)
Km1 = Design speed constant at impeller profile
entrance
Km2 = Design speed constant at impeller profile outlet
Ku = Velocity coefficient of impeller outlet
U2 = Peripheral velocity at outlet (m/s)
The impeller outlet diameter, D2= 60𝑈2
𝑁𝜋 (14)
The outlet vane angle 2 is usually made between
15∘and 35∘. It is usually made slightly larger than the
inlet angle to obtain a smooth continuous passage. And
average value of 22.5∘ of vane outlet angle 2 can be
called 'normal' for all specific speeds.
The Impeller Inlet diameter, D1=D2
D1
D2 (15)
If the inlet edge of the vane is sloped, an average value
is used for D1. D1≈ 𝐷1𝑚 =𝐷1ℎ+𝐷1𝑠
2 (16)
D1s= (1.0~1.1) Do (17)
D1h = (0.7~0.9)Do (18)
The peripheral velocity at the inlet ,U1=𝜋𝐷1𝑁
60 (19)
The blade angle, 1 =tan-1 𝐾𝑏1×𝑉𝑚1
𝑈1 (20)
Where, Kb1=1.1~2.5
Blade Number
Z= 6.5 ( 𝐷2+𝐷1
𝐷2−𝐷1 ) sin (
𝛽1+𝛽2
2 ) (21)
Passage Width
𝑏1 = [𝑄𝑠
′
2𝜋𝐷1𝑉𝑚1] [
𝜋𝐷1
𝜋𝐷1−𝑠1𝑍] (22)
𝑏2 = [𝑄𝑠
′
𝜋𝐷2𝑉𝑚2] [
𝜋𝐷2
𝜋𝐷2−𝑠2𝑍]
(23)
S1=𝛿1
𝑠𝑖𝑛 𝛽1
, S2=𝛿2
𝑠𝑖𝑛 𝛽2
(24)
Where, 1=blade thickness near the leading edge
2= blade thickness at the trailing edge
Impeller Blade Shape
A method to draw the impeller blade by three
circular arcs is used for the present design. Each radius
is given by the corresponding equation. Figure 2 shows
the drawing of impeller blade shapes.
𝜌𝐴
=𝑅𝐴
2 − 𝑅𝐵2
2(𝑅𝐴𝑐𝑜𝑠𝛽𝑏2
− 𝑅𝐵𝑐𝑜𝑠𝛽𝑏)
(24)
𝜌𝐵
=𝑅𝐵
2 − 𝑅𝐶2
2(𝑅𝐵𝑐𝑜𝑠𝛽𝑏
− 𝑅𝐶𝑐𝑜𝑠𝛽𝑐)
(25)
𝜌𝐶
=𝑅𝐶
2 − 𝑅𝐷2
2(𝑅𝐶𝑐𝑜𝑠𝛽𝑐
− 𝑅𝐷𝑐𝑜𝑠𝛽𝑏1
) (26)
Where,
RA=D2
2 , RB=RA-
RA−RB
3,RC=RD+
RA−RD
3, RD=
D1h
2
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 74
Fig. 2 Drawing of Impeller Blade Shape [7]
3. CALCULATION BY MATLAB
clc
Q = input('Enter Desired Flow Rate Q (m^3/min) : ' );
H = input ( ' Enter desired Head (H) in m : ');
N = input ( ' Enter Motor RPM ' ) ;
rho = 1000 ;
Ns = ceil ( N * sqrt ( Q/2) / H^0.75 ) ;
Qs = Q/60 ;
Eff = 0.77 ; % From Pump Efficiency Chart (Ns & Q)
g = 9.81 ;
L = rho * g *Qs * H*1e-3 / Eff ;
% if kW <= 1.5
fa = 0.4;
% elseif kW <= 3.7
% fa = 0.39;
% fa = input (' Choose the value of allowance factor
0.4~0.25 : ');
% elseif kW <= 37.3
% fa = 0.25;
% fa = input (' Choose the value of allowance factor
0.25~0.15: ');
% end
etr = 1 ;
Lr = (1 + fa) * L / etr ;
Ksh = 0.125;
dc = 1000 * Ksh * ( Lr/N)^ (1/3) ;
dsh = 1.02*dc;
dh = 1.5 * dsh ;
lh = 1.8 * dsh ;
etv = 1/ (1 + (1.124/Ns^(2/3))) ;
Qsp = Qs/etv ; % m^3 /sec
Kmo = 0.1 + 0.00023 * Ns ;
Vmo= Kmo * sqrt ( 2 * g * H )
Do = sqrt ( 4 * Qsp/(2*pi * Vmo) + (dh/1000)^2 ) ;
Ku = 1.054; % from Stepanoff Chart
U2 = Ku * sqrt ( 2 * g * H) ;
D2 = ceil (1000 * 60 * U2 / (pi * N)) ; % mm
Di = stpnD ( Ns); % from Stepanoff Chart
D1 = D2 * Di ;
D1s = 1.1 * Do ;
D1h = 0.9 * Do ;
U1 = pi * (D1/1000) * N/60 ;
Km1 = 0.1614; % from Stepanoff Chart
Vm1 = Km1 * sqrt ( 2 * g * H) ;
Km2 = 0.119: % from Stepanoff Chart
Vm2 = Km2 * sqrt ( 2 * g * H) ;
beta2 = 22.5;
Kb1 = 1.2 ;
beta1 = ceil ( atand ( Kb1 * Vm1 /U1)) ;
Z = ceil( 6.5 * ( ( D2 + D1) / ( D2 - D1)) * sind ( (beta1
+beta2)/2)) ;
if D2 < 200
St = 2.5 ;
d1 = 2 ;
else
St = 2.5 ;
d1 = 3 ;
end
S1 = ceil( d1 /sind ( beta1)) ;
S2 = ( pi * D2 - ( pi * D2 * ( pi * D1 - S1 * Z)/ ( pi *
D1) ) )/ Z ;
d2 = S2 * sind ( beta2) ;
b1 = Qsp * pi * D1 / ( 2*pi * D1 * Vm1 * ( pi * D1 - S1
* Z)) * 1000 ; % m
b2 = Qsp * pi * D2 / ( pi * D2 * Vm2 * ( pi * D2 - S2 *
Z)) * 1000 ; % m
Ra = D2 / 2
Rd = 1000 * D1h / 2
Rb = Ra - ( Ra - Rd)/3
Rc = Rd + ( Ra - Rd)/3
if beta2 > beta1
bb = beta2 - 1 ;
bc = bb - 1 ;
else
bb= beta2 + 1 ;
bc = bb + 1 ;
end
rhoA = ( Ra^2 - Rb^2) / ( 2 * ( Ra * cosd (beta2) - Rb*
cosd( bb)))
rhoB = ( Rb^2 - Rc^2) / ( 2 * ( Rb * cosd (bb) - Rc*
cosd( bc)))
rhoC = ( Rc^2 - Rd^2) / ( 2 * ( Rc * cosd (bc) - Rd*
cosd( beta1) ))
disp(' ')
fprintf ( ' RESULT TABLE \n\n ' )
fprintf ( 'No. of Blades, Z = %10d Nos. \n \n ' , Z)
fprintf ( 'Shaft Diameter, d_sh = %10.2f mm \n \n ' ,
dsh)
fprintf ( ' Hub Diameter, d_h = %10.2f mm \n \n' , dh)
fprintf ( ' Hub Length, L_h = %10.2f mm \n \n ' , lh)
fprintf ( 'Diameter of Impeller Outlet, D_2 =
%10.2f mm \n \n ' , D2)
fprintf ('Diameter of Impeller Inlet, D_1 = %10.2f
mm \n \n ',D1)
fprintf ( 'Outlet Blades Angle, Beta_2= %10.2f degee
\n \n ', beta2)
fprintf ( 'Inlet Blades Angle, Beta_1 = %10.2f
degree \n \n ' , beta1)
fprintf ( 'Inlet Blade Thickness, S_1 = %10.2f
mm \n \n ' , S1)
fprintf ('Outlet Blade Thickness,S_2 = %10.2f mm
\n \n',S2)
fprintf ( 'Inlet Width, b_1 =%10.2f mm\n \n ' , b1*1000)
fprintf ('Inlet Width, b_2=%10.2f mm \n \n ' , b2*1000)
fprintf ('Pump Efficienc = %10.2f %% \n\n ' , Eff*100)
fprintf ( ' Shaft Power = %10.2f kW \n\n ' , L)
fprintf ( ' Input Power = %10.2f kW \n\n ', Lr)
fprintf ( ' Specific Speeds (Ns)= %10.2f rpm \n\n ', Ns)
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 75
4. RESULTS AND DISCUSSIONS
Table 1 shows the calculated result of the impeller
dimension for the sample model. The results are
numerically computed by the MATLAB programming.
Table 1 Results of Impeller Dimension
Shaft Diameter, dsh 38.32 mm
Hub Diameter, dh 57.49 mm
Hub Length, Lh 68.98 mm
Diameter of Impeller Outlet,
D2
220 mm
Diameter of Impeller Inlet,
D1
108 mm
Shaft Power 57.81 kW
Input Power 80.93 kW
Pump Efficiency 77 %
Specific Speed 238
Outlet Blade Angle, 2 22.5 deg
Inlet Blade Angle, 1 21 deg
No of Blades, Z 8 blades
Blade Thickness at Inlet, S1 9 mm
Blade Thickness at Outlet, S2 18.32 mm
Inlet Width, b1 30.83 mm
Outlet Width, b2 41.08 mm
Impeller Blade shapes are the following.
RA= 110 mm , RB= 91 mm, ρA=113 mm ,
RC= 72 mm , RD= 54 mm, ρB= 90 mm ,
ρC= 67 mm
Figure 3 shows two-dimensional view of the
impeller blade profile. The three-dimensional view of
impeller with double suction is shown in figure 4.
Fig. 3 Impeller Blade Profile (2D View)
Fig.4 Three-Dimensional View of Double Suction
Centrifugal Pump Impeller
Table 2 Comparisons of Different Results of Impeller
Dimensions at Different Heads
Head 50 54 60 m
Flow Rates 5.05 5.05 5.05 m3/min
Rotational speed 2980 2980 2980 rpm
Pump Efficiency 77.34 77.13 76.68 %
Shaft Diameter,
dsh
37.32 38.32 39.75 mm
Hub Diameter, dh 55.98 57.49 59.62 mm
Hub Length, Lh 67.18 68.98 71.55 mm
Diameter of
Impeller Outlet,
D2
212 220 232 mm
Diameter of
Impeller Inlet, D1
106 108 110 mm
Shaft Power 53.38 57.81 64.5 kW
Input Power 74.73 80.93 90.3 kW
Specific Speed 252 238 220 -
No of Blades, Z 8 8 7 blades
Blade Thickness
at Inlet, S1
9 9 9 mm
Blade Thickness
at Outlet, S2
17.95 18.32 18.87 mm
Inlet Width,b1 31.84 30.83 28.47 mm
Outlet Width, b2 43.25 41.08 36.94 mm
Table 2 shows the different results of impeller
dimension for the double suction centrifugal pump. In
this study, heads are varied and other input data keep
constant. According to the result table, it can be
observed that the higher the desired head, the larger the
size of the impeller diameter. Also, the values of shaft
and input power have increased when the amount of
required head is increased in design calculations,
whereas impeller diameters and required input power
have decreased when the desired head is reduced.
5. Conclusion
Double-suction pumps are an important type of
centrifugal pump. They are used for large flow rate.
Double-suction pumps have two suction chambers. In
this study, design calculation of impeller is done for the
double-suction centrifugal pump used in water pumping
projects. In the impeller design, diameter of impeller
eye, outlet and inlet diameters, blade angles, number of
blades are computed for the sample parameter of 54 m
of head and 5.05 m3/min of flow rate. The rotational
speed of the drive shaft is 2980 rpm. The outer and
inner diameters of impellers are 0.220 m (220 mm) and
0.108 m (108 mm).
The impeller inlet angle, β1 usually falls in the
range from 10 degree to 25 degree. The calculated value
of inlet blade angle (β1) is 21 degree. And the impeller
outlet blade angle (β2) is assumed as 22.5 degree. The
outlet angle of β2 is made slightly larger than the inlet
angle β1 to obtain a smooth and continuous passage.
The number of blades, Z, depends on the blade angles
and it may be between 5 and 12 blades. According to
the Pleiderer formula, numbers of blade are eight. In
this design, pump efficiency chart from Fluid
Mechanics of Turbomachinery (Kyushu) is used to
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 76
estimate the efficiency. The shaft power and input
power are 57.81 kW and 80.93 kW respectively. The
useful technical data from this study can be provided
for designing and manufacturing a double suction
centrifugal pump.
ACKNOWLEDGMENTS
The author is deeply grateful to his parents and to
all teachers that teach us from childhood up to now. The
author also wishes to express his gratitude to those who
share their knowledge and to all of friends who help
him.
REFERENCES
[1] Htay Htay Win, " Design of Double-Suction
Centrifugal Pump Impeller and Casing", Vol.2 ,
Issue 7, June,2019.
[2] Eugen-Vlad Nastae, “Design and Flow Simulation
for a Centrifugal Pump with Double-suction
Impeller 178”, MATEC Web of Conferences 178,
05018(2018).
[3] Nwe Ne Win, “Design and Flow Analysis of
Double-suction Centrifugal Pump Impeller”, Vol:2,
Issue 11, November, 2016.
[4] Deepak Kumar Kalyan, “Computational Flow
Analysis Through a Double-suction Impeller of a
Centrifugal Pump”, 2013.
[5] K.M. Srinivasan," Rotodynamic Pumps (Centrifugal
and Axial), 2008.
[6] Aung Kyaw Soe. “Design and Calculation of Multi-
stage Centrifugal Pump Impeller”, August,2009.
[7] Kyushu Institute Technology, 1996, Training
Course, "Fluid Mechanics of Turbo machinery,
Japan: Kyushu Institute of Technology.
[8] Austin, H,Church, “Centrifugal Pump and Blower ”,
Wiley and Sons, Inc. 1972.
[9] https://blog.softinway.com/ An Introduction to
Centrifugal Pumps
[10] https://www.ksb.com/centrifugal-pump-
lexicon/double-suction-pump
[11] Double suction Split casing Pumps,50Hz, Swiss
Pump Company AG, Switzerland
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 77
Design and Construction of Pretreatment Water Purification System for Technological
University (Lashio)(500L/hr.)
Than Tun Aung(1), May Thu Aung(2), ThihaKyaw(3)
(1)Technological University (Lashio), Myanmar
(2)Technological University(Hmawbe), Myanmar (3)Technological University (Lashio), Myanmar
Email: [email protected]
ABSTRACT: This paper presents is to provide
purified drinking water for Lashio Technological
University at Hopate village with pretreatment of water
purification system. The water source of Hopate is
mostly dissolved calcium. So, the original water result
is considered. Then, three vertical water tanks for
supply source are modified, so that it can treat and
reduce calcium percentage in water.
During this project, Chemical properties of
components (such as active carbon, zeolite, sodium
chloride etc.) are studied and the diameter of the pipes
which connect to vertical tanks by using the theory of
fluid mechanics and gravity flow is calculated. Then
necessary solutions (flow rate of water, power of pump)
the project are calculated.
Water purification is the process of removing
undesirable chemicals, biological containments,
bacteria, suspended solid and gases from water. The
methods used for water purification include such
physical processes as filtration, sedimentation and
gravity flow. In the project, filtration method and
biological filtration processes such as slow sand filters,
biological active carbon and zeolite (Resin) filter were
mainly used.
It is expected to have about 500 liters of purified
water per hour. This project can solve some water
problems in environment.
KEYWORDS: filtration, sedimentation, water flow
rate, rural area.
1. INTRODUCTION
Water is a basic necessity of man along with food
and air. Fresh water resources usually available are
rivers, lakes and underground water reservoirs. About
71% of the planet is covered in water, yet of all of that
96.5% of the planet’s water is found in oceans, 1.7% in
groundwater, 1.7% in glaciers and the ice caps and
0.001% in the air as vapor and clouds. Only 2.5% of the
Earth’s water is fresh water and 98.8% of that water is
in ice and groundwater. Less than 1% of all freshwater
is in rivers, lakes and the atmosphere. [1]
Water purification is the process of removing
undesirable chemicals, biological contaminants,
suspended solids and gases from water. The goal is to
produce water fit for a specific purpose. Most water is
disinfected for human consumption (drinking water),
but water purification may also be designed for a
variety of other purposes, including fulfilling the
requirements of medical, pharmacological, chemical
and industrial applications. The methods used include
physical processes such as filtration, sedimentation, and
distillation; biological processes such as slow sand
filters or biologically active carbon; chemical processes
such as flocculation and chlorination and the use of
electromagnetic radiation such as ultraviolet light. [3]
Purifying water may reduce the concentration of
particulate matter including suspended particles,
parasites, bacteria, algae, viruses, fungi, as well as
reducing the concentration of a range of dissolved and
particulate matter. The standards for drinking water
quality are typically set by governments or by
international standards. These standards usually include
minimum and maximum concentrations of
contaminants, depending on the intended purpose of
water use.
2. THEORETICAL BACKGROUND
In fluid, dynamic Bernoulli’s principle states that
an increase in the speed of a fluid occurs
simultaneously with a decrease in pressure or a decrease
in the fluid's potential energy. The principle is only
applicable for isentropic flows: when the effects of
irreversible processes (like turbulence) and non-
adiabatic processes (e.g. heat radiation) are small and
can be neglected.
Bernoulli’s principle can be derived from the
principle of conservation of energy. This states that, in a
steady flow, the sum of all forms of energy in a fluid
along a streamline is the same at all points on their
streamline. This requires that the sum of kinetic energy,
potential energy and internal energy remains constant.
Thus an increase in the speed of the fluid – implying an
increase in its kinetic energy (dynamic pressure)-
occurs with a simultaneous decrease in (the sum of) its
potential energy (including the static pressure) and
internal energy. If the fluid is flowing out of a reservoir,
the sum of all forms of energy is the same on all
streamlines because in a reservoir the energy per unit
volume (the sum of pressure and gravitational potential)
is the same everywhere.
Fluid particles are subject only to pressure and their
own weight. If a fluid is flowing horizontally and along
a section of a streamline, where the speed increase it
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 78
can only be because it has moved from a region of
lower pressure to a region of higher pressure.
Consequently, within a fluid flowing horizontally, the
highest speed occurs where the pressure is highest and
the lowest speed occurs where the pressure is lowest.
[4]
Bernoulli’s equation is as follow,
2
2
22
1
2
11 Z2g
V
γ
PZ
2g
V
γ
P++=++
(1)
Where,
Atmospheric pressure = 1P
Initial velocity = 1V
Specific weight = γw
Height of tank 1 = 1Z
Pressure (outlet) = 2P
Outlet velocity = 2V
Height of tank 2 = 2Z
Specific gravity = g
Volume flow rate AVQ = (2)
Where,
V = flow velocity
A = cross-sectional vector area/surface
When laminar flow exists in a system, the fluid
flows in smooth layers called laminae. A fluid particle
in one layer stays in that layer. The layers of fluid slide
by one another without apparent eddies or swirls.
Turbulent flow, on the other hand, exists at much higher
flow rates in the system. In this case, eddies and
vortices mix the fluid by moving particles tortuously
about the cross section. The existence of two types of
flow is easily visualized by examining results of
experiments performed by Osborne Reynolds. A
dimensional analysis, when performed and combined
with the data, shows that the criterion for distinguishing
between these flows is the Reynolds number:
υ
ρVDRe = (3)
where: V = average velocity of the flow
D = inside diameter of the tube
For straight circular pipes, the flow is always
laminar for a Reynolds number less than about 2100.
The flow is usually turbulent for Reynolds numbers
over 4000. For the transition regime in between, the
flow can be either laminar or turbulent, depending upon
details of the apparatus that cannot always be predicted
or controlled. We will sometimes need to have an exact
value for the Reynolds number at transition. We will
arbitrarily choose this value to be 2100.
Table 1. Comparison of laminar flow and turbulent
flow[4]
Laminar flow Parameter Turbulent flow
Parabolic Velocity
distribution
Determined
from
experimental
data
For Re less than
or equal 2100
For between
5x105 and 107
2.1 Specification of pretreatment systems
The components of water purification systems are
(1) Raw Water Tanks
(2) Filters Tanks
(3) Sands
(4) Silica Sands, Sediment
(5) Gravel stone
(6) Active Carbon
(7) Birm
(8) Zeolite
(9) Brine
(10) Purified Water Tank
(11) PVC Pipes
(12) Pipe Sockets
(13) Floating Valves
(14) Frames
Silica (SiO2) is the name given to a group of
minerals composed solely of silicon and oxygen.
Extracted ore undergoes considerable processing to
increase the silica content by reducing impurities. It is
then dried and sized to produce the optimum particle
size distribution for the intended application.
For industrial and manufacturing applications,
deposits of silica-yielding products of at least 95% SiO2
are preferred. Silica is hard and chemically inert and has
a high melting point, attributable to the strength of the
bonds between the atoms. These are prized qualities in
applications like foundries and filtration systems. [6]
Fig 1.Sands Fig 2.Silica Sand
Fig 3.Gravel stone Fig 4.Active Carbon
The gravel itself provides mechanical filtration by
catching large free-floating particles. The gravel, as
well as the filter plate, tank bottom, and lift tubes,
provide a bed for the bacteria of a biological filter.
Carbon filtering is a method of filtering that uses a
bed of activated carbon to remove contaminants and
impurities, using chemical adsorption. Active charcoal
filters are most effective at removing chlorine particles
such as sediment, volatile organic compounds (VOVs),
taste and odor from water. Each particle, or granule, of
carbon provides a large surface area, or pore structure,
allowing contaminants the maximum possible exposure
to the active sites within the filter media. One gram of
activated carbon has a surface area in excess of 3,000
m2 (32,000 ft2).
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 79
2.2 Design Calculation for pipe diameter
(Tank1,Tank2 and Tank3)
Fig 5. Tanks
Calculation for shaft diameter (Tank 1)
0.914m
0.304m
Fig 6. Water Tank 1
Atmospheric Pressure, 2
0 0N/mP =
Initial velocity, m/s 0V0 =
Specific Weight, 39810N/mγw =
Height of tank (from outlet pipe) 0.8255m=
Pressure,
wshP == (4) 28.0982kN/m2551x9810x0.8 ==
Bernoulli’s equation,
4.2m/sV
17.69V
2x9.81
Vx
9810
8.09820.8255
Z2g
V
γ
PZ
2g
V
γ
P
1
21
22
1
211
0
200
=
=
=
++=++
Table 2. Discharge Value of Tank 1
Diameter (d)
(m)
Area (A)
(m2) 2d π/4A =
Discharge (Q)
(m3/s)
d1 = 1 in
= 0.0254
A1 = 5.07 x 10-4 Q = A1V1
= 0.0021
d2 = 1.5 in
= 0.038
A2 = 1.14 x 10-3 Q = A2V2
= 0.0047
d3 = 2 in
= 0.0508
A3 = 0.002 Q = A3V3
= 0.0085
So we select suitable diameter to get the flow rate of
0.0021m3/s for tank 1 (Outlet)
d = 1 in = 0.0254 m
Calculation for specific weight (Tank 2 )
0.0889m Water 0.0254m
0.228m Sand
0.127m Active Carbon
0.127m Gravel(small)
0.127m Gravel(Large)
0.127m Gravel(Large)
0.0889m 0.508m
Fig 7. Water Tank 2
Insert materials are; (a) Sand, (b) Active Carbon, (c)
Gravel (small, large)
Their specific gravity are described below Table,
Specific Weight, γm= Sγw
Table 3. Specific Gravity and Weight
Material Specific gravity
(s)s
Specific Weight
(γ)N/m3
Sand 2.65 26.094 x 103
Water 1 9.81x 103
Active Carbon 1.32 12.949x 103
Gravel (small) 2.1 20.6x 103
Gravel (Large) 2.5 24.525x 103
Calculation for pressure, Pressure, P = γh
Table 4. Calculation for pressure
No. Material Specific
weight (γ)
N/m3
Height
(h)
(m)
Pressure
(P)
(N/m2)
1 Sand 26.094×103 0.9779 9.5932
2 Water 9.81x103 1.2065 31.48
3 Active
Carbon
12.949×103 1.3335 17.27
4 Gravel
(small)
20.601×103 1.4605 30.08
5 Gravel
(Large)
24.525×103 1.5875 38.93
Table 5. Calculation of head and pressure for the whole
process are
Tank Head (m) Pressure(kN/m2)
Tank 1outlet 0.8255 8.0928
Tank 2 inlet 1.1303 11.088
Tank 2 outlet -10.8 -106.672
Tank 3 inlet -10.49 -102.906
Tank 3 outlet -9.7534 -95.68
Note:We calculate with SI units
Bernoulli’s equation,
Tank 1
Tank 2
Tank 3
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 80
54
25
24
5
255
4
244
VV
2x9.81
V7534.9-7366.0
2g
V49.10
Z2g
V
γ
PZ
2g
V
γ
P
=
+=++−
++=++
To find the velocity and pipe diameter, we should know
the head losses and it depend on Reynold’s Number and
type of flow.
Viscosity of water is 0.0091 Poise. The flow cannot be
exceed by 1x105 because Reynold’s no is 194.19 D.
Therefore, by using Bernoull’s formula,
Table 6. Result of pre-treatment tank
Tank Diameter (d)
(m)
Velocity (V)
(m/s)
3 0.0127 0.8047
3 0.0254 0.2011
3 0.0381 0.0894
3 0.0508 0.0502
3 0.0635 0.0322
3 0.0762 0.0223
So we select suitable diameter for tank 3(Outlet)
d = 0.0381m=1.5in, Q = 1.388x10-4 m3/s and with the
velocity of 0.0894 m/s.
3. EXPERIMENT
Original Water Result
Name : TU(Lashio)
Lab Code No. : 034718
Date of Receipt : 4.7.2018
Date of Report : 5.7.2018
Source of Water : TU(Lashio)Hopate Village
Area : LASHIO
No. Post Result Maximum
Permissible
Level
Unit
1. Appearance Slightly
Turbid
-
-
2. Colour(Plati
num,Cobolo
t scale)
7 50 Units
3. Turbidity(Si
lcoda Scale
Unit)
- 25 NTU
4. PH Value 7.7 6.5 to 9.2 mg/l
5. Total Solids 803 1,500 mg/l
6. Total
Hardness (as
CaCO3)
340 500 mg/l
7. Total
Alkalinity
(as CaCO3)
520 950 mg/l
8. Calcium as
Ca
120 200 mg/l
9. Magnesium
as Mg
10 150 mg/l
10. Chloride as
CL
20 600 mg/l
11. Sulphate
asSO4
78 400 mg/l
12. Total Iron as
Fe
Nil 1 mg/l
remarks :chemical portable
check by :ministry of health and sports public health
laboratory(Mandalay)
3.1 Results Data of Pre-treatment Tanks
Pretreatment Tank
Name : TU(Lashio)
Lab Code No. : 1851019
Date of Receipt : 22.10.2019
Date of Report : 23.10.2019
Source of Water : Pretreatment Tank
Area : LASHIO
No
.
Post Result Maximum
Permissib
le Level
Unit
1. Appearance Clear - -
2. Colour(Platinum,
Cobolot scale)
5 50 Unit
s
3. Turbidity(Silcoda
Scale Unit)
- 25 NT
U
4. PH Value 8.1 6.5 to 9.2 mg/l
5. Total Solids 602 1,500 mg/l
6. Total Hardness (as
CaCO3)
40 500 mg/l
7. Total Alkalinity (as
CaCO3)
455 950 mg/l
8. Calcium as Ca 8 200 mg/l
9. Magnesium as Mg 5 150 mg/l
10. Chloride as CL 40 600 mg/l
11. Sulphate asSO4 39 400 mg/l
12. Total Iron as Fe Nil 1 mg/l
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 81
4. ANALYSIS
Fig 8.Comparession of final water results with initial
water results
In tank 1 and 3 there is no negative upward force to
water flow but in the tank 2 head losses and pressure
losses occurs because of inserting materials (i.e., sand,
active carbon, etc.). So, the velocity of water is
changing depend on pressure and head. The velocity
and pipe diameter can change depend on flow rate. To
get to the flow rate of 500l/hr. with the velocity 0.08m/s
we should choose 1.5in diameter.
At the end of water treatment operation, water is
ready to drink. Final water result is checked by ministry
of health and sports (Public Health Laboratory,
Mandalay). This treatment system can mainly reduce
Total solid from 803 mg/L to 660 mg/L as 17 %,Total
Hardness from 340 mg/L to 20 mg/L as 94.1 %,
Sulphate (SO4) from 78 mg/L to 59 mg/L as 24.36 %
and Calcium amount from 120 mg/L to 4 mg/L as 96.67
% .Remark is Chemical Portable. Solar power supply is
absolutely enough for system. So, it is helpful to utilize
in condition with no electricity. It can also impact on
environmental cleanness.
5. CONCLUSIONS
This research project, pretreatment of water purification
system is a modifying type of water treatment. Before
passing raw water through each layer, raw filtration for
local water is considered. So, three vertical water tanks
were used for this process. This is main modifying
method of this project. Due to this method, it can rather
reduce the working rate of machine. This is mainly
considered in local water source. The sources water in
Northern Shan State involves large amount of calcium.
Thus, local people are infected by kidney related
diseases. By this project, it can reduce the health
problem and maintain water and sanitation.
ACKNOWLEDGEMENT
Firstly, the authors wish to express the deepest
gratitude to Dr. Tin San, Pro rector (acting),
Technological University (Lashio), for his kindness,
idea and support for the completion of this research
project.
The authors are deeply grateful and sincerely
thankful to their all teachers, for their suggestions and
valuable discussions during the research project.
Finally, the authors are thankful to everyone who
assisted in completing this research project.
REFERENCES
[1] Chittaranjan Ray and Ravi Jain(Auth) 3rd
ed.,Butterworth Heinemann,Press,2014.
[2] Rajindar Singh, Hybrid Membrane for Water
Purification: Technology, System Design and
Operations, 1ed, Elsevier Science,2006.
[3] Nikolaj Gertsen, Linus Sonderby, Water
Purification ( Air, water and Soil pollution
Science and technology series ), first edition,
press 2009.
[4] William S. Janna, Fluid Mechanic, Fourth
edition, University of Memphis Memphis,
Tennessee, U.S.A., 2010.
[5] Flow of water from tank.
http://www.wikepedia.com
[6] Water purification system.
http://www.waterpurification.com
0
100
200
300
400
500
600
700
800
900
Colo
ur
PH
Val
ue
Tota
l S
oli
d
Tota
l H
ardnes
s
Alk
alin
ity
Cal
cium
Mag
nes
ium
Chlo
ride
Sulp
hat
e
mg/l
Post
Comparession of final water results with
initial water results
Iniitial water results Final water results
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 82
Design, Construction and Performance Testing of Pico Hydro Turbine for Rural
Electrification
Ei Ei Mon(1), Cho Cho Khaing(2)Aung Zaw Lynn(3)
(1)Technological University (Mandalay), Myanmar
(2) Technological University(Mandalay), Myanmar
Email: [email protected]
ABSTRACT: The generation of electricity from water
is the most effective and the cheapest way to get
energy. The pico scale renewable energy is to bring
electricity to remote villages that are not near
transmission lines. In hydropower plant water turbine is
one of the most important parts to generate electricity.
The main purpose of this project is to develop the living
standard in rural areas and to reduce the use of non-
renewable energy. In this research paper, 1 kW pelton
turbine design is based on head and flow rate of
Department of Research and Innovation. The available
head and flow rate are 10 m and 0.02 m3/sec. The
pelton turbine is a tangential flow impulse turbine.
There are two main components of this turbine namely,
runner and nozzle. A 1 kW medium head hydro
concrete turbine is constructed in Taung Da Gone
Industrial 3 at Yangon. The pelton turbine project was
tested at Department of Research and Innovation.
KEYWORDS: Nozzle, Pelton turbine, Pico Hydro,
Renewable Energy, Runner.
1. INTRODUCTION
Nowadays, renewable energy such as bio fuel energy,
wind energy, solar energy, geothermal energy, biomass
energy and hydropower energy is very important.
Firstly, renewable energy technologies are clean energy
that has a much lower environmental impact than
conventional energy technologies. Small scale hydro
power generation is one of the types of renewable
energy. Hydropower systems use the energy in flowing
water to produce electricity or mechanical energy. In
hydro power plants the kinetic energy of falling water is
captured to generate electricity. A turbine and a
generator convert the energy from the water to
mechanical and then electrical energy.
There are several classifications related to the
dimension of hydropower plants. An actually useful
classification is the following.(A Harvey and Brown
1992)
(i) Large hydropower > 100 MW
(ii) Medium hydropower 15 -100 MW
(iii) Small hydropower 1 MW-10 MW
(iv) Mini hydropower 100 kW-1MW
(v) Micro hydropower 5-100 kW
(vi) Pico hydropower up to 5kW
Typical hydroelectric plant is shown in figure 1.
Figure 1. Typical Hydroelectric plant (Sharma, R.K.
2003)
2. THEORETICAL BACKGROUND
A turbine is a rotary mechanical device that extracts
energy from a fluid flow and converts it into useful
work. The work produced by a turbine can be used for
generating electrical power when combined with a
generator. Turbines are also divided by their principle
of operation and can be divided into impulse and
reactions turbine. The impulse turbine generally uses
the velocity of the water to move the runner and
discharges to atmospheric pressure. Reaction turbines
are pressure type turbines that rely on the pressure
difference between both sides of the turbine blades. For
micro-hydro applications, Pelton turbines can be used
effectively at head down to about 20m. Draft tubes are
not required for impulse turbine since the runner must
be located above the maximum tail water to permit
operation at atmospheric pressure. Impulse turbines are
usually cheaper than reaction turbines because there is
no need for a special pressure casing or for relatively
high heads.
A Pelton turbine is a hydraulic turbine where the
runner is rotating from the impulse of water jet on its
buckets. The Pelton wheel is a special type of axial flow
impulse turbine and is used for very high heads. In large
scale hydro installation, Pelton turbines are normally
only considered for heads above 100m. A Pelton
turbine consists of a set of specially shaped buckets
mounted on a periphery of a circular disc as shown in
figure 2. The runner consists of a circular disc with a
Intake
Penstock
Power House
Tail Race
Head Race
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 83
number of buckets evenly spaced round its periphery.
The rim of the runner disc are fastened bucket-shaped
blade which are for a better discharge of the water
divided by a ridge or splitter into two symmetrical parts.
The water jet is deflected by the bucket and thus
transfers its energy to the wheel. In order to achieve the
most efficient position of the bucket for the impinging
water, a notch is made into the edge of the bucket at the
largest radius.
Figure 2. Components of Pelton turbine
2.1 Selection of Turbine
The choice of water turbine depends on the site
conditions, notably on the head of water H and the flow
rate Q. figure 3 indicates which turbine is most suitable
for any particular combination of head and flow rate.
Reaction turbines suited for low head and high flow
rate. Pelton turbine is suitable for high head and low
flow rate.
Figure 3. Choice of Turbine in Terms of Head and
Flow rate
Site selection is a very important factor. The
amount of power obtained, the expense of installation,
and even the applications for which the power can be
used may be determined by the quality of the site. A
careful analysis of the site is necessary in order to
determine the feasibility of the site for use of any kind
and the amount of power obtainable from the site.
Specification data of 1Kw pelton turbine are head 10 m
and flow rate 0.02 m3/sec.
2.2 Design Consideration of Pelton Turbine
The effective head and power available of this Pelton turbine is considered at 10m and 1 kW. The power developed by a turbine is given by the following equation.
P = ηo ρ g Q H (1)
The required shaft power is 1.47 kW.
The specific speed can be calculated from the following equation.
Ns = 45(H)
PN
(2)
The speed of the turbine can be calculated from the following equation.
N=147.7√𝐻 (3)
The following points should be considered while designing a Pelton turbine. The absolute velocity of water at inlet can be obtained by using this equation
V1 = Cv 2gH
(4)
The tangential velocity of wheel is determined the
following factors.
k u =
1V
u (5)
The mean diameter or the pitch circle diameter of the Pelton turbine is known from this equation.
u =60
πDN (6)
Number of nozzle is single jet. Thus the jet diameter of
1000 kW Pelton turbine can be calculated from this
equation
Hz
Q0.545d
0
0 = (7)
Jet ratio is a size parameter for the turbine. This value can be obtained by using this equation.
m = d
D (8)
The number of buckets required for the efficient operation of the Pelton turbine is calculated from this equation.
z = 15+ 0.5m (9)
Table 1, which presents a variation of number of
buckets with jet ratio.
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 84
TABLE 1. Approximate Number of Buckets for a Pelton Turbine
Jet ratio 6 8 10 15 20 25
No: of
bucket
17-
21
18-
22
19-
24
22-
27
24-
30
26-
33
The blade pitch p1p2 on the pitch circle can be obtained
by using this equation.
z
R 2πpp 21 = (10)
The relative velocity with the direction of motion of the vane at outlet is 15˚ Velocity triangle from figure 4.
= 15˚
Figure 4. Inlet and outlet velocity diagram of Pelton
Turbine
(i) Relative velocity of water at inlet
Vr1 = V 1 - u1
(11)
(ii) Whirl velocity of water at inlet and outlet
Vw1 = V1
Vw2 = Vr2 cos - u2 (12)
(iii)Flow velocity of water at outlet
sin =
r2
f2
V
V (13)
(iv) Angle at exit runner
tan β =
w2
f2
V
V (14)
The force exerted by the jet of water to the direction of
motion is given as
Jet force on the runner, F = aV1 (Vw1+Vw2) (15)
Jet force on the bucket can be obtained by using this
equation
( )
( )cosα1V
uVρaVP
1
2
110 −
−= (16)
The centrifugal force on the bucket can be calculated.
C.F = F - P0 (17)
Weight of the bucket is
gR
GuC.F
2
= (18)
In a Pelton turbine design, two parameters are
important.
(i) the ratio of the bucket width to the jet diameter
and
(ii) the ratio of the wheel diameter to the jet diameter
If the bucket width is too small in relation to jet
diameter, the fluid is not smoothly deflected by the
buckets and in consequence, much energy is dissipated
in turbulence and the efficiency drops considerably.
Table 2 shown in the main dimensions of the Pelton
wheel bucket.
TABLE 2. Dimension of Bucket with Respect to Jet
Diameter
Item Minimum
Value
Maximum
Value
Bucket length, L 2.28 do 3.3 do
Bucket width, B 2.8 do 4 do
Notch depth, S 0.44 do 0.625 do
Notch width, M 1.12 do 1.6 do
Bucket depth, E 0.8 do 1.2 do
Bucket height, A 1.75 do 2.5 do
The dimension of Pelton turbine bucket is shown in
figure 5.
Figure 5 Dimension of pelton turbine bucket
2.3 Results Data of Bucket
Table 3 shown the minimum value and maximum
value of the bucket dimensions.
TABLE 3 Result Data of Bucket
Item Minimum Value Maximum Value
Bucket
length, L
52.4mm 75.9mm
Bucket
width, B
64mm 92mm
Notch depth,
S
10.12mm 14.375mm
Notch width,
M
25.76mm 36.8mm
Bucket
depth, E
18.4mm 27.6mm
Bucket
height, A
40.15mm 57.5m
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 85
3. Production Process of Pelton Turbine Runner
Production process of pelton turbine runner are
design and drawing, pattern making, casting and
assembling. Mechanical drawing can be drawn by using
design data. The next step is patter making for casting.
figure 6 show that pattern is made by CNC milling
machine.
Figure 6. Pattern making
After pattern making, the next step is mould making.
The proper mould for this pattern is clay mould as
shown in figure 7.
Figure 7 Mould making
And then, casting for pelton turbine bucket is chosen
by available local aluminum because the weight of the
bucket is 0.2kg. Figure 8 shows the casting process and
Fig 9 shows pelton turbine bucket.
Figure 8 Casting Figure 9 bucket
Final step is assembly of runner as shown in figure
10. To construct the turbine runner, these materials are
required. They are resin, colouring, pigment, talc
powder, fiber mat and hardener. Figure 11 shows
assembly of pelton turbine.
Figure 10 Runner
Figure 11 Assembly of Pelton Turbine
3.1 Performance Testing of Pelton Turbine
Before being tested the turbine and generator
assembly must be set firstly. The turbine is started at no
load conditions. The speed of turbine is measured by
using tachometer. The speed of the turbine is 500 rpm.
And then the load is gradually increased and result are
recorded. The generator output can easily be measured
by using various load. The turbine is tested at five
different loads and head and flow rate are constant. The
water passed through nozzle and is guided to the runner.
For that turbine permanent magnet type 4 pole
generator is used with belt drive which speed increases
three times. During the test, the voltage of the turbine
and the speed was found to decrease depending on the
increasing load. It is the reason that there is no gate
valve to control the water to be increased for increasing
the load. The higher the load, the more flow rate is
required at constant head to get the higher power. But at
that testing, the flow rate is constant at all varying load.
Therefore, the flow rate must be increased to get the
required power.
3.2 Result Data
TABLE 4. Test Result Table No Head
(m)
Speed
(rpm)
Volt
(V)
Load
(watt)
Quan
tity
Power
(watt)
1 10 600 270 100 1 100
2 10 550 230 100 2 300
3 10 500 200 100 2 500
4 10 450 150 100 1 600
5 10 450 130 100 1 700
Total Power 700 watt
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 86
Figure 12. Test Result
4. CONCLUSIONS
This turbine can be used for household in remote areas
to produce 1 kW power for 1 household are easily and
inexpensively. This turbine can be used to
demonstration for hydropower training at DRI. The
required head is 10m to generate 1kW output power.
The flow rate of this turbine is 0.02 m3/sec and the pitch
circle diameter is 0.248m. Number of poles of generator
is 4 pole and the speed of turbine is 500rpm. The
diameter of jet is 23mm and jet ratio is 10. The number
of blade is 20. The performance testing is made at DRI
which is located in Yankin Township. In this research,
the design power is 1kW. The test result is 700 W. At
that testing, the flow rate is constant at all varying load.
Therefore, the flow rate must be increased to get the
required power. So ,this test results are the correct
design of the runner. The turbine can be manufactured
by any simple workshop. It can also be quickly and
easily removed temporarily during flooding of other
adverse condition. The design of Pelton turbine for
others hydro power plant can be calculated by using the
similarity law.
The micro and pico hydro power plant are easily
established at low cost. So, the micro and pico hydro
power generation is the best method for rural
electrification.
ACKNOWLEDGEMENT
The author is grateful to Dr. Kyaw Aung, Professor
and Head, Technological University(Mandalay), for
giving the permission to summit the paper.
The author grateful to her supervisor Daw Cho Cho
Khaing, Associate Professor , Department of
Mechanical Engineering, Technological University
(Mandalay) for her encouragement, patient guidance,
invaluable supervision, kindly permission and
suggestions throughout the research and continuous
guideline.
The author wishes to express gratitude to Dr. Aung
Zaw Lynn, Professor, Department of Mechanical
Engineering Technological University (Mandalay) for
his guidance and suggestion for this paper. The author
wishes to extend her gratitude to her parents, husband
and lovely daughter.
REFERENCES
[1] A Harvey and Brown. 1992. “Micro-hydro Design
Manual” ITDG Publishing.
[2] Sharma, R.K. 2003. A Text Book of Water Power
Engineering. S. Chand and ompany
Ltd.
[3] Khurmi. R.S. 1979. A Text Book of Hydraulic,
Fluid Mechanics and Hydraulic Machines.S.
Chand and Company Ltd. Ram Nagar, New Delhi.
[4] Celso Penche and Inge niero de Minas. 1998.
Layman’s Guide Book. How to Develop a Small
Hydro Site, 2rd. ed. France.
[5] Miroslav Nechleba, Dr Techn., M. 1957.
Hydraulic Turbines. Their Design and
Equipment.
[6] Khin Maung Aye, U. 2001. Fluid
Mechanics. Mechanical Engineering
Department, YTU.
[7] Franke, G.F., D.R. Webb, R.K Fisher, D.Mathur,
P.N Hopping, P.A. March.
1997. “Development of environmentally
Advanced Hydropower Turbine System
Concepts” Voith Hydro, Inc. Report No.: 2677-
0141.
[8] Egual U.Y. 1963. Pelton Turbine, Theory and
Research and Calculation.
[9] Bansal. R.K. 1983. Fluid Mechanics and
Hydraulic Machine. Laxmi Publication,
London, UL.
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 87
Design of Hydraulic Ram Pump and Performance Analysis on Different Parameters
Cho Cho Khaing(1), Aye Aye Khaing(2), Kyaw Aung(3) (1)Technological University (Mandalay), Myanmar
(2) Technological University (Mandalay), Myanmar (3) Technological University (Mandalay), Myanmar
Email: [email protected]
ABSTRACT: Hydraulic ram pump plays the important
role in Myanmar since Myanmar is rich in water
resources. This paper forecasts the performance
characteristics of the designed pump by varying the
supply pipe length, waste valve travel, delivery head,
waste valve diameter and delivery valve diameter. The
designed pump can develop a delivery head of 3.1 m
and deliver 7.728 litre/min with 127 beat/min. Based on
the drive pipe length 6 m and the supply head 1.4 m, the
Rankine’s efficiency is nearly 55% and the
D’Aubuisson’s efficiency is about 64%. The
designed pump can also fulfill for water supply to
remote area.
KEYWORDS: head losses, maximum velocity,
time/beat, flow rate
1. INTRODUCTION The hydraulic ram (or) hydrum is a type of pump in
which the energy of large quantity of water falling through small height is utilized to lift a small quantity of this water to greater height. No external power is required to operate this pump. It can be used for water supply to country side and remote area where a source having large quantity of water at some height is available.[1]
1.1 Components of hydrum
The main parts of a ram pump are hydrum
body, waste valve, delivery valve, air chamber and
relief valve. Ram pumps have a cyclic pumping action
that produces their characteristics beat during operation.
Fig 1. Hydraulic ram pump
1.2 Working principle
The working of a hydraulic ram is based on the
principle of water hammer or inertia pressure developed
in the supply pipe. Initially as the water flows down the
supply pipe into the valve chamber, the waste valve
being open, the water flows through it to the waste
water channel. As the rate of discharge past the waste
valve increases, the flow of water in the supply pipe
accelerates. [1]
Due to the accelerating flow in supply pipe and the
static column of water in the supply tank, the pressure
in the valve chamber rapidly increases and acts the
lower face of the waste valve. Then, the waste valve
almost instantaneously closes due to the force is greater
than the weight of the waste valve.
The instantaneous closing of waste valve brings the
water in the supply pipe suddenly to rest and causing
the pressure rise in the valve chamber due to inertia.
Then, the delivery valve is forced open and the water
flows through the delivery valve into the air vessel and
delivery pipe.
Thus some of the flowing water is directly supplied
to the delivery tank and some of it is stored in the air
vessel. An air vessel assists in providing a continuous
delivery of water at a uniform rate.
The flow of water through the delivery valve
continues until the momentum of the water in the
valve chamber is destroyed, the delivery valve then
closes and the waste valve opens, thus again causing the
water to flow from the supply tank to the waste water
channel. This constitutes one cycle of operating or one
beat of the hydraulic ram. [1]
2. BASIC THEORY OF HYDRAULIC RAM PUMP 2.1 Conservation of energy in fluid mechanics
The Bernoulli’s equation can be considered to be a statement of the conservation of energy appropriate for flowing fluids. The energy equation (or) the extended Bernoulli’s equation taking into account gains and losses of head is given by
lpump hzg
VhHz
g
Vh +++=+++ 2
2
221
2
11
22
(1)
Where h = pressure head (m)
V = average velocity of fluid (m/s)
z = elevation head (m)
Hpump = head added by pump (m)
hl = head loss (m)
g = acceleration due to gravity (m/s2)
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 88
2.2 Head losses
The Darcy-Weisbach Equation of head loss in a pipe
is
gD
fLVhl
2
2
= (2)
Head loss in pipe fitting may be expressed as
g
Vkhl
2
2
= (3)
in which the coefficient k depends on the size, shape
and type of fitting. The value of k and f can be found
from standard reference handbooks.
The total head loss coefficient for driving section and
delivery section may be assumed by
im kkD
fL
A
A+++
=
2
2
1lh (4)
Where km is minor total losses coefficient and ki is
impulse valve loss coefficient.
In this study, the supply pipe diameter, waste valve
diameter and delivery valve diameter are selected the
same. Friction factor f is assumed 0.024 for smooth
pipe. From the Moody diagram, Reynold’s number is
estimated and the maximum velocity for turbulent flow
can be determined by
s
mD
VRe
= (5)
Where υ is the kinematic viscosity of water.
2.3 One dimensional unsteady flow equations Since the head contributed to water acceleration in the
driven pipe, the effective head available to accelerate the liquid in the pipe during the drive cycle is given by
dt
dV
g
L
g
Vh s
ls =−2
H2
(6)
Similarly, the one dimensional unsteady flow during the delivery section may be expressed
dt
dV
g
L
g
Vh s
ld =+2
h2
(7)
Where H = supply head
h = delivery head
hls = total head loss coefficient in drive section
hld = total head loss coefficient in delivery section
Ls = supply length of pipe
By integrating (6), the time required to close the
waste valve (or) the time during which the velocity in
the supply pipe builds up from zero to Vm, t1 and the
volume of water in drive section are determined by
2gH
Vhtanh
gHh
2Lt
2
mls1
ls
2
s
1
−= (8)
( )
−
=
2gH
Vh1
1ln
h
ALVol
2
mlsls
ss
s (9)
Similarly, the volume of pumping water in delivery
section and the time for which the waste valve remains
closed (or) the delivery valve remains open, t2 are
determined by integrating (7).
+=
gh
Vh mld
21ln
h
AL(Vol)
2
ld
ssp
(10)
2gh
Vhtan
ghh
2Lt
2
mld1
ld
2
w
2
−= (11)
So, the pumping flow rate can be determined by
( )
( )21 tt
VolQ
p
p+
= (12)
2.4 Efficiency of hydraulic ram
The Rankine’s efficiency is given by
HQ
hQη
s
p
r = (13)
and the D’Aubuisson’s efficiency can be determined
by
( )
( )pQ+
+=
s
p
dQH
QhHη (14)
3. DESIGN PARAMETERS OF HYDRUM
Design specifications of hydrum are as shown
in Table 1.
Table 1. Design Specifications of Hydrum
No Design Parameters Symbol Value unit
1 Supply head H 1.4 m
2 Supply pipe diameter Ds 0.0381 m
3 Waste valve diameter Dw 0.0381 m
4 Delivery valve diameter
Ddv 0.0381 m
5 Delivery pipe diameter Dd 0.0190 m
6 Waste valve travel b 0.0120 m
7 Length of waste valve Lw 0.0762 m
8 Supply pipe length Ls 6 m
9 Delivery head h 3.1 m
Table 2 shows the designed results of Hydraulic Ram
Pump.
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 89
Table 2. Designed Result of Hydrum
No Parameter Symbol Value Unit
1 Maximum velocity Vm 0.782 m/s
2 Time for which the waste valve remains open during each beat
t1 0.4705 s
3 Time for which the waste valve remains close during each beat
t2 0.0018 s
4 Total time for each beat
t 0.4723 s
5 Supply flow rate Qs 0.5169 Litre/s
6 Pumping flow rate Qp 0.1288 Litre/s
7 Rankine’s Efficiency
ηr 55.17 %
8 D’Aubuisson’s efficiency
ηd 64.12 %
The three dimensional hydraulic ram pump
with the designed data is created by Solid works Software.
Fig 2. Detail drawing of designed Hydrum
4. PERFORMANCE ANALYSIS ON DIFFERENT
PARAMETERS
Fig. (3) shows the variation of efficiency, time for
one beat and pumping flow rate by changing the supply
pipe.
According to Fig. (3), the efficiency and pumping
flow rate tend to decrease and the time required for one
beat increases if the supply length is longer.
Fig 3. Efficiency, time for one beat and pumping flow
rate on various supply pipe
Fig. (4) presents the efficiency, time for one beat and
pumping flow rate at different waste valve travel.
Fig 4. Efficiency, time for one beat and pumping
flow rate on various waste valve travel
If the waste valve travel is higher, the efficiency and
pumping flow rate are more and time for one beat is
shorter.
Fig. (5) describes the efficiency, time for one beat
and pumping flow rate on various delivery head.
Fig 5. Efficiency, time for one beat and pumping flow
rate on various delivery head
Fig.(5) can be seen that the delivery head increases,
the efficiency also increases although the time for one
beat is approximately constant.
Change of the waste valve diameter and delivery
valve diameter doesn’t affect significantly on the
efficiency, time for one beat and pumping floe rate as
shown in Fig.(6) and (7).
Fig 6. Efficiency, time for one beat and pumping flow
rate on various waste valve diameter 5 6 7 8 9 10 11 12 13
0
0.2
0.4
0.6
0.8
1
1.2
1.4Efficiency, time for one beat and pumping flow rate on various supply pipe length
supply pipe length(m)
eff
icie
ncy,
tim
e /
beat,
pum
pin
g f
low
rate
efficiency
time for one beat,s
pumping flow rate,L/s
5 6 7 8 9 10 11 12 13
x 10-3
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
0.55
0.6
Efficiency,time for one beat and pumping flow rate on various waste valve travel
waste valve travel(m)
eff
icie
ncy ,
tim
e/b
eat,
pum
pin
g f
low
rate
efficiency
time for one beat,s
pumping flow rate,L/s
2 2.5 3 3.5 4 4.5 5 5.5 6 6.50
0.1
0.2
0.3
0.4
0.5
0.6
0.7Efficiency,time for one beat and pumping flow rate on various delivery head
delivery head (m)
eff
icie
ncy,t
ime/b
eat,
pum
pin
g f
low
rate
Efficiency
time for one beat,s
pumping flow rate,L/s
0.025 0.03 0.035 0.04 0.045 0.05 0.0550.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
0.55
0.6
Efficiency,time for one beat and pumping flow rate on various waste valve diameter
diameter of waste valve (m)
eff
icie
ncy,t
ime/b
eat,
pum
pin
g f
low
rate
efficiency
time for one beat,s
pumping flow rate,L/s
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 90
Fig 7. Efficiency, time for one beat and pumping flow
rate on various delivery valve diameter
5. CONCLUSIONS
The designed hydraulic ram pump is aimed to use in
domestic. It can develop 3.1 m head and deliver 7.728
litre/min without using electricity power (or) fuel. The
designed efficiency is analyzed based on Rankine’s
efficiency equation. The designed hydraulic ram pump
can be used in village which locate on hillside and
remote areas which doesn’t have the electricity grid.
Since the mechanism of a hydrum is simple and doesn’t
require maintenance cost, it is crucial for small scale
water supply schemes in developing countries.
ACKNOWLEDGEMENT
The author would like to express her special thanks
to Dr. Aye Aye Khaing, Professor, Department of
Mechanical Engineering, Technological University
(Mandalay) for her encouragement, suggestion and Dr
Kyaw Aung, Professor and Head, Department of
Mechanical Engineering, Technological University
(Mandalay) for his valuable guidance of this paper.
REFERENCES
[21] Modi P.N., Hydraulics and Fluid Mechanics
[22] Victor L. Streeter and E. Benjamin, Fluid
Mechanic 7th Ed,(1951)
[23] David, J.P. and Edward, H.W., Schaum’s Outline
of Theory and Problems of Fluid Mechanics and
Hydraulics, SI (Metric)Edition , McGraw Hill
Book Company,Singapore,1985.
[24] Watt, S.B.,. Manual on a Hydraulic Ram for
Pumping Water, Intermediate Technology
Publication Ltd., London, 1982
[25] Design and Fabrication of A Hydraulic Ram
Pump, Nari Suraj, “International Journal of
Engineering Research and Technology” Special
Issue, Conference Proceedings,2018.
0.025 0.03 0.035 0.04 0.045 0.05 0.0550.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
0.55
0.6
Efficiency,time for one beat and pumping flow rate on various delivery valve diameter
delivery valve diameter (m)
eff
icie
ncy,t
ime/b
eat,
pum
pin
g f
low
rate
efficiency
time for one beat,s
pumping flow rate,L/s
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 91
Design and Heat Dissipation of Internal Combustion Diesel Engine Exhaust Valve
Aung Zaw Lynn(1), Kyaw Linn Soe(2)
(1)Technological University (Mandalay), Myanmar (2)Technological University (Mandalay), Myanmar
Email: [email protected]
ABSTRACT: This paper mainly describes the design
and heat dissipation of internal combustion engine
exhaust valve. As the airflow passes various
components and stages of the intake system, inlet valve
does not undergo excessive heat from working engine.
But the exhaust valves are hot enough to cause
immature failure. Therefore this paper intends to study
the design and temperature distribution of the exhaust
valve by using related theoretical concepts. To consider
the design, the specifications of 72 hp four cylinder four
strokes diesel engine are used. The design of the
exhaust valve is calculated and valves are used to
control gas flow to and from cylinder of automotive
internal combustion engines. The most commonly used
valve is the poppet valve. The valve itself consists of a
disc shaped head having a stem extending from its
center at one side. The valve-seat angle of exhaust valve
kept 45 degrees in this design. Although both inlet and
exhaust valves receive heat from combustion, the inlet
valve is cooled by incoming air, whereas the exhaust
valve experiences a rapid rise of the temperature in the
valve head, seat insert, and under head area from hot
exhaust gases. To make the design of valve, the
dimensions of bore and stroke of 100 mm and 115 mm
from 72 hp four cylinder diesel engine was adopted.
The material of exhaust valve is AISI 4340 low alloy
steel and this paper also describes the process of
temperature distribution of exhaust valve at peak
combustion temperature 1616 K for three different
materials.
KEY WORDS: exhaust valve, temperature
distribution, heat power, combustion gas, ic engine
1. INTRODUCTION
The purpose of the internal combustion engine is
the production of mechanical power from the chemical
energy contained in the fuel. The fuel-air mixture or
fresh air is actual working fluids. The work transfers
from working fluids which provide the desired power
output by moving mechanisms. About thirty five
percent of the heat generated is lost into the
surroundings of combustion space, remainder being
dissipated through exhaust and radiation from the
engine. Additional heat is produced by friction between
the moving parts.
Heat moves from the area of high temperature to
the area of low temperature. The heat from the engine is
moved to the atmosphere by cooling with water and air.
If it is not removed from engine, engine components
will damage cause of excessive temperature. The heat
from combustion process affected mainly to the piston
head, cylinder wall, exhaust valve and exhaust pipe.
The exhaust valve may become hot enough to cause
preignition or may fail structurally. Besides, preignition
would increase the cylinder head temperature further
until engine failure or complete loss of power results.
The charge to burn will contact the wall of the
combustion chamber and upper cylinder head area. If
this charge temperature of these parts will reduce the
delay period, it may cause knocking. For the side of
inlet valve, the fresh air which is at the atmosphere
temperature and pressure is entered through the inlet
valve. Therefore, the exhaust valve suffers from damage
more than the inlet valve because of excessive heat.
The valve face angle (with the plane of the valve
head) is generally kept 45° or 30°. A smaller face angle
provides greater valve opening for a given lift, but poor
sealing because of the reduced seating pressure for a
given valve spring load. Due to this reason, in some
engines, the inlet valve face angle may be kept 30° or
45° whereas the exhaust valve face angle is only 45°, as
this increases its heat dissipation. The temperature
distributions are affected by heat conduction in valve
seat and heat transferred by convection and radiation
from combustion gases.
Fig 1. Configuration of Inlet and Exhaust Valves [13]
2. DESIGN CONSIDERATION OF EXHAUST
VALVE
2.1 Description of Main Parameters
B. The design parameters of exhaust valve are
as follow;
• Thickness of the valve head
• Diameter of valve face
• Diameter of valve stem
• Maximum valve lift
The exhaust valve design of internal combustion
engine in this paper is used as the flat-headed type
Spring
Piston
Head
Cylinder
Wall
Exhaust Valve
Inlet
Valve
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 92
poppet valve. To design the valve, the port diameter is
known data which is got from the engine specifications.
The valve stem diameter (ds), the valve face diameter
(df), the valve disc thickness (t), and the maximum
valve lift (hlift) can be considered from the calculation of
poppet valve design. The sketch of poppet type valve is
shown in Fig 2.
Fig 2. Conical Poppet Valve in the Port [9]
The thickness of the valve head (t) can be
determined empirically from the following relation.
σ
Pdkt 2
p1= (1)
where,
t - thickness of valve disc in mm
k1 - constant for metal
dp - diameter of exhaust port in mm
P2 - maximum gas pressure in N/mm2
σ - permissible bending stress in N/mm2,
(100 N/mm2 ~ 120 N/mm2 for alloy
steel) [9]
The constant for metal (k1) varies for alloy steel
and for cast iron which are 0.54 and 0.42 respectively.
The maximum gas pressure is the pressure which may
be taken as nine to ten times of the mean effective
pressure (Pi). The permissible bending stress for the
material of valve may be taken as 100MPa which is for
alloy steel. The valve face diameter can be determined
from the following equation.[9]
α)]sin(902[tdd pf −+= (2)
where,
df - diameter of valve face in mm
α - valve seat angle in 45 degrees
The diameter of valve stem can be determined from
the following equation.
6.35mm8
dd
p
s += (3)
where,
ds - diameter of valve stem in mm
The maximum valve lift can be obtained by using
the following equation.
hlift =0.25 dp
cos∝ (4)
where,
h - maximum valve lift in mm
dp - diameter of exhaust port in mm
α - valve seat angle in 45 degrees
2.2 Specifications of 72 HP Four Cylinder Diesel
Engine
The following table shows specifications which are
used to design the valve.
Table 1. Specification of 72 hp Four Cylinder, Four
Stroke DI Diesel Engine
No
.
Parameter Value Unit
1 Cylinder bore 100 mm
2 Piston stroke 115 mm
3 Piston displacement 0.903×10
-3
m3
4 Compression ratio 20:1 -
5 Power output 72(53.71
2)
hp(kW
) 6 Rated speed 4000 rpm
7 Atmospheric
temperature
298 K
8 Atmospheric pressure 0.1013 MPa
9 Weight of the valve 0.12 kg
10 Max: suction pressure 0.025 MPa
11 Cylinder pressure
when exhaust valve
open
0.3004 MPa
12 Exhaust port diameter,
dp
31.82 mm
13 Valve length 130 mm
The exhaust valve from 72 hp four cylinder diesel
engine is made up of low alloy steel. This low alloy
steel is ranged at the standard of AISI4340. From this
internal combustion engine, the intake process
temperature and pressure are at the standard condition.
The starting pressure of compression stroke is 0.8~0.9
of atmospheric pressure. From the adiabatic process, 1-
2, the temperature is 987.71 K and the pressure is 5.3
MPa. The combustion peak temperature is 1616 K and
the combustion pressure is 5.3 MPa at constant pressure
process. The exhaust temperature is 751 K which is
calculated from the p-V and T-s diagrams. 2.3 Estimation of Combustion Gas Temperature
The volume of the cylinder can be determined as a
position of crank from the compression ratio, stroke,
bore and connecting rod length.
df
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 93
Fig 3. Basic Geometry of Reciprocating IC Engine
The difference between the maximum and
minimum volume is known as the displacement
volume, Vd, displacement volume can also be
represented as a function of the bore and stroke.
The displacement volume is
LD4
πV 2
d = (5)
= 9.032×10-4 m3
The following parameters define the basic
geometry of a reciprocating engine. They are used to
obtain the gas temperature.
Compression ratio, rc = 20
c
cdc
V
VVr
+= (6)
Vc = 4.7537×10-5 m3
where,
Vd - the displacement volume
Vc - the clearance volume.
Crank radius, r can be calculated from the
following Equation (7).
2
length Stroker = (7)
= 0.0575 m
Equivalent length of the connecting rod, Le, can be
obtained from the following equation (8).
λ
rLe = (8)
= 0.21296 m
where,
λ - the constant value
The range of λ is 0.25 to 0.5. Use the value of λ is 0.27.
Distance between the crank axis and piston axis, s
s = rcosθ + (Le2 + r2sin2θ)1/2 (9)
= 0.1747 m
where,
θ - the crank angle is 125 degrees measure
from BDC during compression process.
The cylinder volume Vcyl will be computed to
consider the average temperature at the crank angle 125
degrees.
s)r(LD4
πVV e
2
ccyl −++= (10)
= 7.996×10-4 m3
The temperature of the gas, Tg will be average
temperature. The temperature will be found from the
following ideal relationship.
M = 176 kg/kmol
ρa = 1.2 kg/m3
R = 8.3413 kJ/kmol K
Tg =PcylVcylM
ρaR[
rc−1
rcVd] (11)
= 1500 K
where,
M - Molar mass of fuel, kg/kmol
ρa - density of air, kg/m3
R - universal gas constant, kJ/kmol K
Pcyl - Pressure at crank angle 125 degrees
Tg - Temperature at crank angle 125 degrees
2.4 Determination of Heat Transfer Coefficient for
Air at 1500 K
The heat transfer coefficient is determined by using
the thermophysical properties at 1500 K. This value is
practically applied to find the thermal resistance of the
exhaust valve. The thermophysical properties of exhaust
gas are shown in the following TABLE 2.
Table 2. Thermophysical Properties of air at 1500 K[14]
No Parameter Symbol Value Unit
1 Density ρ 0.2322 kg/m3
2 Thermal
conductivity к 100 x 10-3 W/mK
3 Specific heat
capacity cp 1.230 kJ/ kgK
4 Viscosity μ 557 × 10–7 Pa-s
5 Prandtls No: Pr 0.685 -
6 Kinematic
viscosity N 240 × 10–6 m2/s
The heat transfer model of the valve stem is based
on the flow upon the cylindrical rod. The value of
Reynolds number is shown as Equation (12).
Re =ρv(dp −ds)
μ = 8.06 x 103 < 5 x 105 (12)
where,
ρ - Density of exhaust gas, kg/m3
µ - Dynamic viscosity of exhaust gas, Ns/m2
v - Velocity of exhaust gas, 90 m/s ~ 100 m/s
for high speed engine [9] This condition is laminar flow. Therefore, the
Nusselt number defines as Equation (13).[12]
NuD = 0.664 ReD1/2
Pr1/3 (13)
The heat transfer coefficient for exhaust gas can be
obtained from Equation (14).
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 94
l
kNuh = (14)
h = 40.43 W/m2K
where,
h - Convection heat transfer coefficient,
W/m2K
2.5 Distribution of Heat Transfer Rate for Exhaust
Valve
The distribution of heat transfer rate on exhaust
valve considers by heat conduction and radial effects as
the following Fig 4. The heat flow transfers from valve
face to along the valve stem. The temperature of the
valve stem edge will be predicted by solidworks
simulation. It is considered when exhaust valve is
opening period after combustion.
Fig 4. Sketch of Thermal Resistance
Total Thermal Resistance can be computed by
equation (15).
∑RT = 1
hi Ai+
L1
kA1+ [
11
Ahi
+ 11
Ahi
+1
L2kA2
]
−1
+1
h0 A0
(15)
where,
k - thermal conductivity, 44.6 W/m-K for
alloy steel.
Area of valve head,
A1 = (df+dp
2) t
(16)
Area of valve stem,
A2 =π
4ds
2 (17)
Area of gas flow between exhaust port and valve
stem,
A = π
4(dp
2 − ds2) (18)
Area of valve tip, Ai
Ai = π
4di
2 (19)
Area of valve stem tip, Ao
Ao = π
4do
2 (20)
Heat power for exhaust valve can be calculated by
equation (20).
q =Ti−To
∑ RT (21)
where,
q - Heat power for exhaust valve, W
3. DESCRIPTION OF DESIGN PARAMETERS AND
THERMAL DISTRIBUTION
The following results from Table 3 shows the
comparison of existing and theoretically based data of
the exhaust valve. Material of the exhaust valve is the
same for the existing valve and designed valve.
Table 3. Design Parameter of Exhaust Valve
No Specifications Symbol
Design
Value
(mm)
1 Diameter of valve face df 36.192
2 Thickness of the valve
disc t 3.0912
3 Diameter of valve stem ds 10.328
4 Maximum valve lift hlift 11.25
Table 4. Result Table of Heat Rate for Exhaust Valve
No Parameters Values Units
1 Total Thermal
Resistance, ƩRT’’ 155.505 K/W
2 Area of valve head, A1 1.05x 10-4 m2
3 Area of valve stem, A2 8.38 x 10-5 m2
4 Area of valve tip, Ai 1.03 x 10-3 m2
5 Area of valve stem tip,
Ao 8.38 x10-5 m2
6 Area of gas flow , A 7.11 x 10-4 m2
7 Heat power 8.5 W
4. ANALYSIS OF TEMPERATURE DISTRIBU-
TION FOR EXHAUST VALVE
The following figures show the tempertaure
distribution of exhaust valve at peak combustion
temperature 1616 K. In fact, the temperature on the tip
of the valve stem is higher than the ambient
temperature. Therefore, the temperature on the valve
stem tip can be seen 357.7 K in AISI 4340 low alloy
steel, 400.9 K in alloy steel and 342.4 K in AISI 4130
steel above ambient temperature according to
simulation results while running the engine. This results
are simulated in same parameters of exhaust valve with
different materials. The heat dissipation of these
materials are not very different but alloy steel is more
than others but less density. Therefore it’s size will be
larger than this designed parameters. Both materials of
AISI 4340 and AISI 4130 are same density but AISI
4340 is more heat power and thermal conductivity than
AISI 4130.
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 95
Fig 5. Temperature Distribution of Exhaust Valve
at Gas Temperature 1616 K (AISI 4340 Low Alloy
Steel)
Fig 6. Temperature Distribution of Exhaust Valve at
Gas Temperature 1616 K (Alloy Steel
Fig 7. Temperature Distribution of Exhaust Valve at
Gas Temperature 1616 K (AISI 4130 Steel)
Fig 8. Temperature Distribution of Exhaust Valve at
Gas Temperature 1500 K (AISI 4340 Low Alloy Steel)
According to the above review and simulation
results, the material AISI 4340 is more suitable than
AISI 4130 for this designed parameters.
The following table is described the results of
exhaust valve for AISI 4340 in peak combustion
temperature of 1616 K and average combustion
temperature of 1500 K.
Table 5. Result Table of Peak and Average Combustion
Temperature of Exhaust Valve for AISI 4340
Sr.No Name of Items
Peak Tempature
Average Temperatur
e 1 Material AISI4340 AISI4340
2 Melting
point 1705 K 1705 K
3
Combustion temperature 1616 K 1500 K
4 Valve stem tip temperature
298 K 298 K
357.7 K 331.5 K
5 Heat Power (Theorectical)
8.5 W 7.73 W
6 Heat Power (Simulation) 8.1 W 7.54 W
7 Deviation 4.7 % 2.4 %
5.CONCLUSIONS
The exhaust valve is one of the most critical parts
for the combustion system. It effects not only engine
performance but also volumetric efficiency. The
operating temperature is the most significant factor in
the performance of the exhaust valve. The physical
properties of the valve stem effects the temperature
distribution rate. Exhaust valve stem generally fails by
overheating. It is not considered as the coating effect
which can reduce the temperature from the valve. This
paper presents the heat dissipation process of the
exhaust valve used in the internal combustion engine. In
this paper, the material of exhaust valve is low alloy
steel (AISI 4340) and the length of valve is 130 mm.
The heat power generated from the exhaust valve is 8.5
Technological University Lashio Journal of Research & Innovation Vol. 1, Issue: 4
TULSOJRI September, 2020 96
W. The parameters of the designed valve is covered to
prevent the failure resulted from thermal stress because
the melting point temperature of alloy steel is 1432 ˚C
(1705 K). The exhaust valve stem can be performed to
reduce having valve stem tip temperature of 357.7 K
from peak combustion temperature of 1616 K.
ACKNOWLEDGMENT
The author would like to express his special thanks
to U Kyaw Lin Soe, Lecturer from Technological
University (Mandalay), Department of Mechanical
Engineering for his valuable advice and discussion.
Also author appreciate to U Kyaw Minn Khant,
Automobile Engineer from United Auto Car Service in
Mandalay for supporting some technical data.
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Mechanical Analysis on Exhaust Valve, (2014).
[9] A Text Book of Machine Design, “Internal
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[10] Hornik. A.; Jędrusik D., and K. Wilk, Unsteady
State Heat Flow in the Exhaust Valve in
Turbocharged Diesel Engine Covered by the
Layer of the Carbon Deposit, (2012).
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