Yawmeter for Hypervelocity Flows New

7/28/2019 Yawmeter for Hypervelocity Flows New

1/68

DESIGN, FABRICATION AND COMPUTATIONAL

ANALYSIS OF YAWMETER FOR HYPERVELOCITY

FLOWS

A PROJECT REPORT

Submitted By

Y. THOOYAVAN

in partial fulfillment for the award of the degree

of

MASTER OF ENGINEERING

in

THERMAL ENGINEERING

SUBMITTED TO THE

FACULTY OF MECHANICAL ENGINEERING

MOHAMED SATHAK ENGINEERING COLLEGE,

KILAKARAI-623 803.

ANNA UNIVERSITY :: CHENNAI 600 025

JULY 2013

1


2/68

ANNA UNIVERSITY : CHENNAI 600 025

BONAFIDE CERTIFICATE

Certified that this project report "DESIGN, FABRICATION AND

COMPUTATIONAL ANALYSIS OF YAWMETER FOR

HYPERVELOCITY FLOWS"is the bonafide work of "Y.THOOYAVAN" who

carried out the project work under my supervision.

SIGNATURE OF HOD SIGNATURE OF SUPERVISOR

Dr.A.THILAIVANAN, M.E.,MBA.,Ph.D. Mr. BALA MURUGAN, M.E.,

Department of Thermal Engineering Assistant professorDepartment of Thermal Engineering

Mohamed Sathak Engineering College, Mohamed Sathak Engineering College,

Kilakarai 623 806. Kilakarai 623 806.

Submitted for the viva voce held on ___________

Internal Examiner, External Examiner,

2


3/68

ACKNOWLEDGEMENT

First of all I express our heartfelt thanks to God almighty for everything,

without whom we are nothing in this world.I would also like to express our sincere gratitude to the management of

Mohamed sathak Engineering College, for providing us a conductive work

atmosphere.

I am very much grateful to our Director, for providing all our necessary

facilities.

I thank our principal ALHAJ Dr. J. Mohamed Jahabar, Ph.D., (IITBombay) FIE, MISTE, MIEEE, MASME.for his encouragement and

constructive ideas.

I am very much thankful to our HOD (Thermal Engg.,)

Dr.A.Thilaivanan,M.E.,Ph.D., who has been a constant source of inspiration.

I would like to express my sincere thanks to Dr.B.Kanagasuntharam,Ph.D.

Head of the Department, Mechanical Engineering, who has been giving vital moral

support at each and very step. I am also thankful to him for all the resources he has

rendered and as coordinated efforts.

I am greatly indebted to Mr.V.BalaMurugan,M.E. Department of

Mechanical Engineering, who has masterfully guided me in accomplishing this

project I should not forget his incredible talent in crafting my rough drafts into

publishing works and providing fresh ideas, sound advice, and constant

enthusiasm.

3


4/68

1. INTRODUCTION

4


5/68

1. INTRODUCTION

1.1. GENERAL FEATURES OF PRESSURE PROBES:

The size and geometry of pressure probes shows considerable variation

according to their particular use and the number of flow quantities that are required

at the same time. Fundamentally, however they all exploit the distribution of

pressure which occurs over a body when it is immersed in a moving fluid. These

pressure variations depend mainly on wind speed so that with suitable choice of

body shape and location of holes to serve as pressure tappings,a probe may be

calibrated in a known wind stream; the relationship between pressure and wind

speed can then be established over a range of speeds. The design of certain probes

involving simple shapes, such as cylinders or spheres, can have some basis in

theory, but the final design usually becomes a compromise aimed at minimizing

the effect of factors such as Reynolds number, Mach number and stream

turbulence. Ideally calibration should be unaffected by these, but in practice, this is

not usually attainable although probes can be designed so that extraneous effects

are insignificant over large ranges of stream conditions.

For many purposes the measurement of wind speed alone is not sufficient. A

knowledge of flow direction as defined by two angles, together with total pressure

and static pressure, are common additional requirements, and can be catered for

either singly, in groups or in a single instrument. The degree of complexity of bothprobes and its method of operation will depend on how many flow quantities are to

be derived from one set of operations, and in general, the number of flow

quantities which can be derived from single probe is related to the number of

pressure tapings and the number of attitudes at which it is presented to the flow.

5


6/68

Compared with probes intended specially for the measurement of only one

quantity, multi purpose instruments, because they involve some degree of

compromise in sensitivity to all the quantities that they are intended to degree, are

often some what less accurate and tend in addition to have larger minimumdimensions. Nevertheless, the first of these advantages is usually far outweighed

by errors arising from sequential positioning of single purpose probe, where a

number of quantities are required at any one position in the flow.

General features which are desirable in probes selected for the measurement

of flow quantities at a point in a fluid can be summarized as follows:

(a) Small size offering a minimum of disturbance to the flow.

(b) Rapid response.

(c) Robust and simple construction.

(d) Calibration both infrequent and unaffected by flow conditions.

(e) All measurements close to one point.

No special significance attaches to the order in which the above properties

are given, the importance of each being dependent on the particular application

envisaged. It can be seen that some of the properties are incompatible as in the case

of (a) and (b) where some lag in pressure response is inevitable in probes of very

small size. It follows that practical limits enforce a compromise design expect

where the need for any one feature is over-riding: for example, in certainboundary-layer applications, considerable pressure-response lag must be tolerated

in order to provide a probe of sufficiently small dimensions.

6


7/68

1.2. BASICS OF PROBE CALIBRATION:

Before proceeding to any detailed of methods, it is useful to call to mind and

unique relationship which exists between pressure and velocity in steady incompressible flow and upon which all pressure-probe methods rely, namely that,

neglecting viscosity, change in Kinetic pressure are accompanied by equal and

opposite changes in static pressure.

The static pressure defined for present purposes as the pressure sensed by a

measuring device at rest relative to the fluid (i.e. moving with the fluid). The total

pressure defined as the pressure obtained when the fluid is brought to rest relative

to the probe.

It follows that the kinetic pressure can be determined directly by measuring

(H-P).If we require the velocity V itself, we need to determine the density as well.

This is usually done by measuring the (absolute) pressure and temperature at some

point in the flow field, and invoking the perfect gas equation: in practice the

pressure changes arising from the motion in incompressible flow are negligible in

comparison with the absolute pressures.

7


8/68

2. LITERATURE REVIEW

8


9/68

2. LITERATURE REVIEW

2.1. TOTAL - PRESSURE PROBES:

The type of obstruction that disturbs the flow least is simply cylindrical tube

aligned with the flow. A pressure tapping is provided at the end facing the flow

and the tube is usually bent through a right angle at some distance down stream

to form a stem so that the conventional total-pressure tubes takes the forms.

If the measurement of total pressure is required at fixed intervals across a

stream, as in the investigation of wake flows, it is common practice to mount a

number of total-pressure tubes on a single stem containing the pressure leads to

each tube; this arrangement is termed a comb or rake and may be fitted with

one or two additional probes for measuring other flow quantities such as static

pressure and direction.

If a pitot tube is inclined to the flow it reads low, but, for the types of

geometry commonly used, the sensitivity of the reading to misalignment is not

great; consequently the flow direction need not be known very precisely when total

pressure is measured with this type of instrument for most purposes it is

insufficient to sight the tube against some simple indicator of flow direction suchas a light thread streaming in the wind : alternatively, the instrument may be

orientated until the reading reaches the maximum.

9


10/68

2.2. MEASUREMENT OF STATIC PRESSURE:

The simplest type of static-pressure probe consists of a body of revolutionwith its axis aligned with flow, two including forward-facing holes for the

additional measurements of total pressure; co-ordinates for the nose shape shown

in the figure. Because the flow is brought to the rest at the nose, the surface

pressure there is greater than that of the undisturbed flow. The surface pressure is

always equal to the undisturbed static pressure at some point on the nose.

However, owing to the rapid variation of surface pressure with distance over the

nose, pressure tapings are not located in this region when they can be located

further aft in positions where the downstream pressure gradient is less steep.

In subsonic flow the effect of the stem of the instrument is to increase the

upstream static pressure above that of the free stream, and so the pressure field of

the stem can be used to balance locally the pressure fall caused by the nose. a

pressure tapping located in the region where the head effect and the stem effect

balance can therefore record the free-stream static exactly in practice the balance

need not be exact, as the error will be known from the calibration; any new design

must be calibrated in order to establish misalignment errors and the effects of

changes in Reynolds number and Mach number.

10


11/68

2.3. MEASUREMENT OF FLOW SPEED:

The pitot-static tube consist of a static-pressure tube which has been

provided with an additional orifice at the nose for measuring stagnation pressure;

as shown in the figure, it is easily constructed of two concentrate cubes, which are

connected to the form of manometer so that H,P,(H-P)or h/P can be measured as

required. various geometric shapes are used for the head, particularly

hemispherical, ellipsoidal and special shapes for super sonic flow; also, the tubes

are often bent at right-angle at some distance down stream of the static-pressure

tapings. The design principle of pitot-static combinations are same as for pitot and

static tubes used separately; the pitot orifice present no special probes and does not

appreciably affect the reading of static side of the instrument. for a given size of

pitot orifice, however a combination probe is necessarily of greater over all size,

and may therefore disturb the flow to a greater extend than separate pitot and static

tubes; these considerations are important in the exploration of the linear structure

of a given flow field, in supersonic flow and in regions where the flow conditions

vary rapidly in later case, it should be remembered that the pitot and static holes

are well displaced from each other in the axial direction which precludes the use in

many situations.

Despite these limitations the Pitot - static tube has one major advantagenearly all other pressure probes; it can give high degree of accuracy without prior

calibration provided that it is used in a subsonic uniform flow and is made to

specific dimension.

11


12/68

Where P1 denotes the reading for the pitot orifice and P2 that of the static

side of the instrument, for the standard designs with the hemispherical, ellipsoidal

or tapered conical heads, when correctly aligned with the flow, a value of K` ofunity gives the wind correctly to within percent(1 percent in PV). This

conclusion based on test the tubes7.9mm external diameter in air at normal

atmospheric condition and appears to be valid at least over the range of wind

speeds from 6 to60m/s(20 to 200ft/s).it probably hold also down to wind speed of

about 1m/s, especially for the ellipsoidal head. These results can also be applied to

the tubes of different geometrical size to other fluid conditions over the same range

of Reynolds number(3300 to 33000,based on external diameter),provide that the

flow speed is not high enough for compressibility effects to begin to assert them

selves(in air at room temperature around 60m/s).

There are two common ways in which flow direction can be measured with

pressure probes; in either case the probes are similar and have symmetrical

arrangement of sensing holes. In the first, known as the null-reading or equi-

balanced method. The probe is oriented to a position at which the same pressure is

recorded at each hole; the flow direction then can be related to the geometric of the

probe. This relationship is easily established in the first instance by rotating the

probe about its fore-and-aft axis through 180 degrees and realigning to give equal

pressures; the true flow direction then lies at half the angle between the two probe

axis positions. The second method is to keep the probe stationary and observepressure or pressure difference whose relationship to flow direction is obtained

from calibration in which the probe is orientated in a steady known flow. The first

of these methods is recommended where possible because it is an easy matter to

design probe which will give a high value for pressure difference per unit change

12


13/68

in flow direction if this value needs to be fairly constant for only a small range of

angle; such probes can be used with simple narrow-range manometers and may

used without calibration. A further advantage lies in the comparatively short time

required to obtain a steady manometer reading of nearly equal pressure as againstdifferent pressures requiring a displacement of air and gauging fluid thought the

manometer system.

The effects of the gradient on the accuracy of yawmeter measurements can

be large when the direction of the gradient is from one sensing hole to another. The

separation distance between the holes should then be as small as possible; this

figure illustrates one method by which this can be achieved.

Yawmeter consisting of a body with pressure tapings are basically stronger than

tube configurations and lend them to application which requires internal heating

and cooling of the probe. Although they in valve a fairly large separation of the

sensing holes, transverse-cylinder yawmeter having two holes drilled normal to the

cylinder axis and at the same distance alone it are sometimes convenient for 2D

flow exploration when used with rotating to give a null-reading alignment. They

can be used with square or spherical ends and cantilever mounting or completely

spanning the flow. Holes can be drilled at positions of maximum surface pressure

gradient.

Wedge, chisel, conical, pyramid and Conrad require less precision in

manufacturer although the pressure response of small instruments can again beslow. The sensitivity of probes from this general class increases with nose angle

which may be anything between 15 degrees and 90 degrees, depending on the

mach number range for which the probe is designed. Although the pyramid probe

may appear to be more difficult to make than a conical form, the positioning holes

13


14/68

is less critical and its pitch and yaw characteristics are more nearly independent of

each other. It should be noted, however, that the chisel design, which could be

regarded as part pyramid, does not shows this insensitivity to pitch Probes

incorporating spheres, cones, pyramids, etc.Conical and pyramid probes, etc.

Most of the instruments in the group were first designed as an alternative to

spherical types in order to simplify manufacture. In addition to having a more

easily generated shape, pressure holes on the nose are more closely grouped than is

possible on a spherical end and for the same external diameter measurements are

made more nearly at a point in the flow. A disadvantage is the loss of sensitivity to

flow direction of about 40 percent or more as compared with spherical ended

yawmeter.

Both conical and pyramid four-hole probes have been used as yawmeter, but

a four-hole pyramid probe can be used for measurements in 3D flows with a

method used also with two-tube yawmeter and described. This procedure involving

calibration constants and readings taken to the two altitudes to the flow was not

found to be usefully applicable to conical probes of 99 degrees apex angle because

the sensitivity to yaw of the side hole-pressures was found to be too dependent on

flow direction in pitch.

The influence of gradients of velocity variations in flow direction on probesof this type depend largely on the size of the probe. The design of figure is small

enough for many situations involving gradients transverse to the flow direction, but

the downstream distance of the static manifold from the tip is too large where the

flow quantities vary in the stream direction.

14


15/68

2.4. CONICAL PROBES:

Conical probes have been used for the determination of mach number, totalpressure and flow direction at supersonic speed, their shape offering less

interference to the flow than hemispherical types. Although the inclusion of a

central pressure taping precludes a sharp forward apex and the bow wave is

detached at all times, the smaller the apex angle on the cone the wider range of

Mach number over which a smooth pressure responses obtained. At the same time,

sensitivity of side holes to change in the flow direction increases with angle of the

cone so that some compromise is necessary. A cone angle of 60 degree is found to

be suitable for speeds above M=1.5 although angles of 40 degrees have been used

to give a slightly lower limit.

2.5. WEDGE-TYPE COMBINATION PROBES:

The main feature is a sharp-edge, narrow-angle wedge supported by small-

bore tubes one of which forms a Pitot tube. Combined static-pressure and yaw-

sensing holes are drilled one either side of the wedge at slightly different distance

from the leading edge. This variation is enforced by lack of internal space, but the

error in yaw angle measurement incurred is slight because the static pressure varies

title along the sides of the wedge.

The Pitot tube is found to read total pressure with the same accuracy as a

plain tube if the tip is arranged to project slightly forward to the wedge is shown.

With the purpose of obtaining total-pressure readings closer to the wall through

which the probe was passed, one version has been made with a second pitot tube

15


16/68

located below the wedge on the side adjacent to the stem. This device was only

partially successful in that the static pressure readings were found to be less

reliable than with earlier type.

A staticPressure calibration curve for the probe of figure 48a is given in

figure 49 where it can be seen that the instrument is usable up to high subsonic

speeds provide some correction dependent on M can be applied. A possible source

of error in the measurement of static pressure has been shown to be the condition

the leading edge of the wedge; departure from a sharp has been found to cause

greater sensitivity of static reading to Mach number. The really sharp edge is also

found to be the only form for which the indicated flow direction remains

independent of Mach number.

For the measurement of flow direction in conditions of severe transverse

gradients of total pressure as are often met in gas turbine flows, wedge probes are

considered to be the most accurate of all types which have been tried. The adverse

effects of pressure gradients transverse to the flow and in planes containing pairs of

yaw sensing holes have been discussed in chapter 5.Figure 21 compared the

performance of wedge and transverse cylinder yaw meter when transverse aero the

wake of turbine compressor stator blade.

16


17/68

3. DESIGN METHODOLOGY

17


18/68

3. DESIGN METHODOLOGY

3.1. DESIGN OF CONICAL PROBE:

Conical probes have been used determination of the Mach number, total

pressure and flow direction at supersonic speeds, their shape offering less

interference to flow the hemispherical types. Although the inclusion of central

pressure tapping precludes a sharp forward apex and the bow wave is detached at

all times. The smaller the apex angle of the cone of the wider the range of mach

over which a smooth pressure response to obtained. At the same time, sensitivity of

the side holes to change in the flow direction increases with angle of the cone, so

that some compromise is necessary. A cone angle of 60 degrees is found to be

suitable for speeds above M = 1.5 although angle of 40 degrees have been used to

give a slightly lower limit.

Various design parameters are furnished below:

3.1.1. TUNNEL BLOCKAGE:

When supersonic flow cannot be established in the wind-tunnel test section,

the resultant condition is caused primarily by

1) Insufficient compression ratio,

2) Excessive moisture (or condensed gas) in the airstreams,3) Too large model.

18


19/68

3.1.2. MODEL SIZE:

It is usually desirable to utilize a model of the maximum size in order to

realize the greatest aerodynamic forces and minimize instrumentation errors. Anadded advantage is that the larger the model the more nearly the Reynolds number

approaches that of free flight. However, the size of any test configuration is limited

by the blocking factor.

It is the condition at which a normal shock would occur and would initiate

subsonic flow in the test section.

The flow characteristics along the length of the model should be considered

if an extensive after body is present. The flow conditions at the nose of the model

would present no problems; however, as the critical area ratio for blockage is

approached, the shock interference tends to move upstream from the subsonic

diffuser toward the rear of the model, shock wave interference could then exist on

afterbody.

3.1.3. MODEL DESIGN:

It is generally desirable to make a wind- tunnel model as larger as possible

in order to maximize air loads and thus increases the accuracy of measurements.

The larger size also provides a more realistic Reynolds number. More over, as themodel size is increased the problems of design and fabrication become less

difficult. Several factors limit the maximum model size for any given facility, and

these are:

19


20/68

1. Tunnel blocking, this governs maximum frontal area.

2. Reflected shock-wave interference, which governs model length

3. Limitation on the aerodynamic loads, including the dynamic effects

of starting and stopping the wind tunnel.

3.1.4. SHOCK WAVES:

Formation of Shocks Pressure waves will build up, adding to each other to

form a shock wave, at the boundary between the supersonic and subsonic flow.

The shock wave between the supersonic and subsonic flow will always form at

right angles to the airfoil surface. Therefore, it is known as a Normal Shock

Wave. We can state two simple rules of thumb:

1. A normal shock wave always forms between supersonic and

Subsonic flow

2. The flow behind a normal shock wave is always subsonic.

The Oblique shock wave is not really much of a problem for supersonic

design. It does represent a certain amount of drag, since energy goes into its

formation, but very little can be done about that.

Behind normal shocks and some low supersonic Mach number shocks there

exists a region of subsonic flow. This region tapers away to nothing at somedistance from its origin; but should it strike a wall of the find tunnel before

vanishing, pressure disturbances at the wall can propagate back through this

subsonic region and influence the flow properties over the model.

20


21/68

When a bow wave from a model strikes a wall of the wind tunnel it is

reflected into the stream and may impinge on the afterbody of the model.

Therefore, the model length should be chosen such that the reflected shock

intersects the tunnel axis well aft of the model base. This requirement seriouslylimits the model length for the test at low supersonic mach numbers, but becomes

less significant as the Mach number increases. The limiting length of the model is

also strongly dependent on the width of test section,

21


22/68

4. FABRICATION TERMINOLOGY

22


23/68

4. FABRICATION TERMINOLOGY

4.1. MATERIAL SELECTION:

As the yawmeter undergoes intense pressure and velocity under sonic speed

conditions, the materials which has used for the fabrication of yawmeter is of high

hardness and strength.

Table: 4.1. Material Details:

COMPONENT MATERIAL HARDNESS

Probe cone high carbon steel(alloy) 60-70 hrc

Probe adapter stainless steel 35-40 hrc

Wedge high speed steel 50-60 hrc

Afterbody adapter stainless steel 35-40 hrc

Probe tubes stainless steel 40 hrc

Tubes(outlet) Polypropylene ---------

Indexing mechanism stainless steel 40 hrc

23


24/68

4.2. FABRICATION PROCESS:

Materials which are used for yawmeter are determined as per thehardness and area of usage.

Raw materials are purchased without heat treating as per the design

parameters.

Each and every component are machined and processed by the

concern operations by special machines

The following machining processes were done for the fabrication

o CNC Milling (wedge)

o Shaping (wedge)

o M1TR (wedge, probe adapter,

afterbody adapter, indexing

mechanism)

o Jig boring ( wedge, probe adapter,afterbody adapter, indexing

mechanism)

24


25/68

o Cylindrical grinding (probe cone, probe adapter,

afterbody adapter)

o CNC wire cut (probe cone)

o CNC lathe (probe adapter, afterbody

adapter)

o Buffing (all components)

All the components are machined by high precision special machines and are

made accurate up to h7 tolerance and surface finished ().

All materials are heat treated and oil bath annealed.

25


26/68

Fig: 4.1. Probe Cone

Fig: 4.2. Probe Adapter

26


27/68

Fig: 4.3. Wedge

27


28/68

Fig: 4.4. Adapter

28


29/68

Fig: 4.5. Yawmeter Full Apparatus

29


30/68

5. EXPERIMENTAL ANALYSIS

30


31/68

5. EXPERIMENTAL ANALYSIS

5.1. CONE ANGLE & SHOCK ANGLE:

The shock wave must be attached to the model

(max) for M=3 Is 46( For Conical Probe)

In my case I have selected =20

For M=3 and =20

Shock wave angle is-29.3

= Nose semi angle

5.2. TUNNEL BLOCKAGE:

Model area:

(Am)=2954.8741mm^2

Test Section Area:

(At)= 90000mm^2

(Am)/ (At) = 2954.8741/ 90000

= 0.0328319

Tunnel Blockage Factor =3.28

Table: 5.1 Shock Wave Angle Chart:

31


32/68

Mach no. Shock wave angle

= 5 10 15 20 25 30

1.05

72.4 -- -- -- -- --

1.1 65.6 67.0 -- -- -- --

1.2 56.4 57.5 60.6 72.5 -- --

1.3 50.5 51.4 53.4 58.0 -- --

1.4 45.5 46.3 48.3 52.8 59.3 --

1.6 39.0 39.4 41.6 46.2 52.2 59.1

1.8 34.0 34.6 37.1 41.6 46.7 52.6

2 30.1 31.3 33.7 38.0 43.0 48.3

2.5 23.8 24.8 27.8 32.2 37.1 42.6

3.0 20.0 21.3 24.7 29.3 34.2 39.5

3.5 16.9 19.4 23.4 27.7 32.7 38.3

Detached Bow Wave (-nose semi angle)

5.3. MECHANICAL ANALYSIS:

Consider a Single Probe

32


33/68

Fig: 5.1. Mechanical Analysis of Probe

Pressure acting on it is

PRESSURE (P) = 5 BAR

LENGTH (L) =0.03m

DIAMETER (d) =0.01m

YOUNGS MODULUS (E) =210N/mm^2

ASSUMING THE CONICAL PROBE AS AN CYLINDER

AS SHOWN IN FIGURE (a)

Area of c/s= (d^2)/4

A =7.8539*10-5 mm2

Load acting F = P*A

33

5BAR


34/68

F =39.2699N

5.4. BUCKLING (OR) CRIPPLING LOAD (FCR):

FCR=(n2EA)/(L/K) 2

K= (I/A)

I= (/64)*d^4

K=2.50001*10-3

n=0.25

FCR=282.608N

F< FCR

Now Assuming the Pressure Acting Over the Entire Length of the Probe

34


35/68

Fig: 5.2. Load Distribution

the load distribution is shown in fig (a)

TOTAL LOAD (W) =5 * 105 * 0.03 * 0.01

W=150N

MAX BENDING MOMEMT (Mmax )

Mmax = (150*0.03)/2

Mmax =2.25N-m

b=M/Z

Z=I/Y

Y=D/2

Y=5 * 10-3 m

Z=9.8174*10-8

b=229.19*104N/m^2

35

W/L


36/68

6. COMPUTATIONAL ANALYSIS

36


37/68

6. COMPUTATIONAL ANALYSIS

6.1. TWO DIMENSIONAL ANALYSIS :

In order to get accurate and precise results on the yawmeter theoretical

analysis have been made by flow analysis programs like Gambit and Fluent.

The following are the graphical representation of the results obtained under

several sonic speeds.

The various input velocities and parameters which are initiated before

analyzing are as follows:

Table: 6.1 Input Data (2D Analysis):

S.NO VELOCITY AMBIENT PRESSURE AMBIENT TEMPERATURE

1 Mach 1 1.01325 bar 288 K

2 Mach 2 1.01325 bar 288 K

3 Mach 2.5 1.01325 bar 288 K

4 Mach 3 1.01325 bar 288 K

37


38/68

MACH 1:

Fig: 6.1. Static pressure Fig: 6.2. Static Temperature

Fig: 6.3. Turbulent Viscosity Fig: 6.4. Velocity Magnitude

38


39/68

Fig: 6.5. Static pressure (wall) Fig: 6.6. Velocity Magnitude (wall)

Fig: 6.7. Static Pressure (pf) Fig: 6.8. Velocity Magnitude (pf)

39


40/68


41/68

Fig: 6.13. Static Pressure (wall) Fig: 6.14. Velocity Magnitude (wall)


41


42/68

MACH 2.5:

Fig: 6.17. Turbulent Viscosity Fig: 6.18. Static Temperature

Fig: 6.19. Velocity Magnitude Fig: 6.20. Static Pressure

42


43/68

Fig: 6.21. Velocity Magnitude (wall) Fig: 6.22. Static pressure (wall)


43


44/68


45/68


46/68


47/68

MACH 1:

Fig: 6.33. Static Pressure Fig: 6.34. Velocity Magnitude

Fig: 6.35. Static Temperature Fig: 6.36. Turbulent Viscosity

Fig: 6.37. Static Pressure Fig: 6.38. Velocity Magnitude

47


48/68


49/68


50/68



Fig: 6.54. Static Temperature Fig: 6.55. Turbulent Viscosity

50


51/68

7. RESULT

51


52/68

7. RESULT

7.1. ACTUAL RESULT:

The design of conical probe for a 0.3m test section wind tunnel at VSSC is

obtained by analyzing various aerodynamic and mechanical parameters.

1. The conical probe can be used up to Mach number range of 1.2 to 6

2. The probe designed is safe in mechanical loading

3. Tunnel blockage factor for the design is with on the limit

4. Two more probes can be added in the vertical plane

5. Probe can be used for finding the Mach number determination and

the flow angularity in side the test section.

52


53/68

7.2. COMPUTATIONAL RESULT:

Detached waves are formed when the flow velocity exceeds more than Mach

number 2.

Flow through the entire test section is considered to be turbulent which

produces wake at the rear side of the wedge.

In three dimensional analysis, when the velocity exceeds Mach 2, the flow is

diverged.

When the flow is sonic and if it is exceeding more than Mach 1.5 shock

diamond is formed which falls behind after body of the yawmeter.

53


54/68


55/68


56/68


57/68


58/68

9. CONCLUSION AND INFERENCE

The present design and fabrication of the yawmeter setup was done

successfully and the results were satisfactory. This yawmeter setup is designed as

of horizontal axis and yaw movement is possible in single plane.

As a futuristic development the yawmeter can be made as a vertical plane or

even can be made for both the axis. By doing so, we can get yaw movement in

both the axis of plane.

The materials which are used to fabricate yawmeter is made by high strength

and high hardness metals which are heat treated. But there is a possibility of testing

the yawmeter setup higher than mach 2 and mach 2.5.

By adding alloys and high strength metals like titanium and ceramics, high

temperature resistant and high strength can be obtained.

And if further more modified like electronic axis rotational system for

indexing mechanism using stepper motors, high precision axis rotation and

indexing can be achieved.

58


59/68

10. COST ESTIMATION AND EXPENDITURE

59


60/68

10. COST ESTIMATION AND EXPENDITURE

10.1. RAW MATERIAL COST:

Table: 10.1 Raw Material Cost:

S.No Component Material Weight Cost

1. Probe ConeHigh Carbon

Steel (Alloy)0.3 Kg Rs.2,700

2. Probe Adapter Stainless Steel 0.45 Kg Rs.1,100

3. WedgeHigh Speed

Steel

1.5 Kg Rs.4,300

4. After Body Stainless Steel 0.8 Kg Rs.2,200

5.Indexing

MechanismStainless Steel 3.0 Kg Rs.5,600

60


61/68


62/68

11. REFERENCES

62


63/68

11. REFERENCES

(1) A.L. braslow and E.C. Knox, Simplified Method of Determination of

Critical Height of Distributed Roughness Particles for Boundary Layer

Transition at Mach Numbers from 0 to 5, NASA TN 4363, September 1958.

(2) Kopal, Z. Tables of supersonic flow around cones. Mass. Inst. Technology

Tech. Report No. 1, 1947.

(3) HESS, J.L., SMITH, A. M. O., RIVELL, T. L. Systematic design of

improved static pressure sensing probes. Douglas Aircraft Co. Inc.,

Engineering paper No. 1181., October, 1961.

(4) SWALLEY, F. E. Measurement of flow angularity at supersonic and

hypersonic speeds with the use of a conical probe. NASA TN D-959, 1961.

(5) ANDREWS, D. R., SAWYER, W. G. The calibration of a 60o cone to

measure Mach number, total pressure and flow angles at supersonic speeds.

Current papers aero. Res. Coun. Lond., No. C. P. 628, 1962.

(6) RANEY, D. J. Flow direction measurements in supersonic wind tunnels.Current papers aero. Res. Coun. Lond., No. C. P. 262, 1956.

(7) BARRY, F. W. comparison of flow directions probes at supersonic speeds.

J. aeronaut. Sci., 1962 (9), 750.

63


64/68


65/68


66/68

66


67/68

67


68/68

Date post:	03-Apr-2018
Category:	Documents
Upload:	jebadaniel
View:	225 times
Download:	0 times

Yawmeter for Hypervelocity Flows New

Documents