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THERMODYNAMICS-III.C. ENGINE TESTING

By:- Harjinder Pal Singh

Lect. Mech.Dated:20-09-2012 Govt. Polytechnic College Batala

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I.C. ENGINE TESTING

INTRODUCTION: The basic task in the design and development of engines is to reduce the cost and improve the efficiency and power output. In order to achieve the above task, the ‘development engineer’ has to compare the engine developed with other-

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I.C. ENGINE TESTING

INTRODUCTION: -engines in terms of its output and efficiency. Towards this end he has to test the engine and make measurements of relevant parameters that reflect the performance of the engine.

I.C. engine generally operates within a useful-

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I.C. ENGINE TESTING

INTRODUCTION: -range of speed. Some engines are made to run at fixed speed by means of speed governor, which is its rated speed. The performance of the engine depends on the inter-relationship between the power developed, speed and the specific fuel -

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I.C. ENGINE TESTING

INTRODUCTION: -consumption at each operating condition within the useful range of speed and load.

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I.C. ENGINE TESTING

The following factors are to be considered in evaluating the performance of an engine:(i) Maximum power or torque available at each

speed within the useful range of speed.(ii) The range of power output at constant speed

for stable operation of the engine. The different speeds should be related at equal intervals within the useful speed range.

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I.C. ENGINE TESTING

(iii) Brake specific fuel consumption at each operating condition within the useful range of operation.(iv) Reliability and durability of the engine for the given range of operation.

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I.C. ENGINE TESTING

Purpose of Testing an I.C. Engine:In general the purpose or significance of testing an I.C. engine is to determine the following:(i) To determine rated power output with respect

to the fuel consumption in Kg per Kw-hr of brake power output.

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I.C. ENGINE TESTING

Purpose of Testing an I.C. Engine:(ii) To determine the mechanical and thermal efficiencies of the engine.(iii) To see the performance of the engine when loaded at different loads.

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I.C. ENGINE TESTING

Purpose of Testing an I.C. Engine:(iv) To determine the quantity of lubricating oil required per bp Kw hr.(v) To determine the quantity of cooling water required per bp Kw hr.(vi) To determine the overload carrying capacity of the engine.(vii) To prepare the heat balance sheet of the engine.

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I.C. ENGINE TESTING

Some Important Terms as per ISI Standard:1. Speed : The speed of an engine is the mean

speed of its crank shaft in revolutions per minute (RPM), except in case of ‘free piston’ engines where the speed is the number of cycles per minute , of the reciprocating components.

2. Steady Load Speed Band: It is the maximum total variation in speed expressed as a %age of the mean speed, which may occur while there is no change in external load conditions.

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I.C. ENGINE TESTING

Some Important Terms as per ISI Standard:3. Continuous Power: The power which the engine is capable of delivering continuously between the normal maintenance intervals stated by the manufacturer, at stated speed and under stated operating conditions.4. Indicated Power: It is the total power developed in the working cylinder by the gases on the combustion side of the working pistons.5. Friction Power: It is the power consumed in frictional resistance.

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I.C. ENGINE TESTING

Some Important Terms as per ISI Standard:6. Brake Power: It is the total power measured at the driving shaft.7. Fuel Consumption: The quality of fuel consumed by the engine per unit time of the stated power and under stated operating conditions.8. Specific Fuel Consumption: It is the quantity of fuel consumed per unit of power per unit of time. It is generally expressed in gms of fuel consumed per kW hr or B.H.P./bp.

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I.C. ENGINE TESTING

Some Important Terms as per ISI Standard:9. Standard Operating Conditions : The following are the standard operating conditions:(i) Mean Barometric Pressure: It is taken as 736

mm of mercury (Hg).(ii) Intake Air Temperature : It is taken as 3000k or

270C

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I.C. ENGINE TESTING

Engine Power :The energy flow through the engine is expressed in three distinct terms. They are ‘indicated power’, ip, ‘friction power’, fp and ‘ brake power’, bp.

‘Indicated power’ can be computed from the measurement of forces in the cylinder and ‘break power’ from the measurement of forces at the crank shaft of the engine. The ‘friction power’ can be estimated by motoring the engine or from the difference between ip and bp. i.e. fp=ip-bp

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I.C. ENGINE TESTING

Indicated Mean Effective Pressure (Pim):It may be defined as, the constant pressure acting over the full length of the stroke and capable of producing the same amount of work, as is actually produced during the complete cycle of the engine. It is generally denoted by ‘Pim’ or i.m.e.p.

As, the pressure in the cylinder varies throughout the cycles and the variation can be expressed with respect to the volume or crank angle rotation to obtain p-V or p-θ diagrams,

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Indicated Mean Effective Pressure (Pim):respectively. However, such a continuous variation does not readily lend itself to simple mathematical analysis in the computation of ip. If an average pressure for one cycle can be used, then the computations become far less difficult.

Refering figure, as the piston moves back and forth between TDC and BDC, the process lines on the p-V diagram indicated the successive states of the working fluid through the cycle.

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Indicated Mean Effective Pressure (Pim):The indicated network of the cycle is represented by the area 1-2-3-4 enclosed by the process lines for that cycle. If the area of rectangle A-B-C-D equals, the area 1-2-3-4, the vertical distance between the horizontal lines AB and CD respectively gives the ‘indicated mean effective pressure’, imep. It is a mean value expressed in N/m2, which when multiplied by the displacement volume or swept volume, Vs gives the ‘same indicated net work’ as is actually

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Indicated Mean Effective Pressure (Pim):

p-V diagram for an ideal four-stroke cycle engine

I.C. ENGINE TESTING

Indicated Mean Effective Pressure (Pim):produced with the varying pressures.PimX(V1-V2) = Net work of cyclePim=Also, Pim=

= If, a= area of indicator diagram in cm2. l= length of the indicator diagram in cm

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I.C. ENGINE TESTING

Indicated Mean Effective Pressure (Pim):And s = spring no. or spring strength in N/m2 per cm.Then Pim = N/m2

The value of the area measured, when divided by the piston displacement and multiplied by the spring number of the indicator, results in the mean ordinate or indicated mean effective pressure , Pim.

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I.C. ENGINE TESTING

Brake Mean Effective Pressure (Pbm):It may be defined as the mean effective pressure acting on the face of piston, which would develop brake power equivalent to that during actual varying pressure condition. It is generally denoted by Pbm or b.m.e.p.

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I.C. ENGINE TESTING

Brake Mean Effective Pressure (Pbm):Friction mean effective pressure (Pfm) is that portion of mean effective pressure (Pim), which is required to overcome friction losses and brake mean effective pressure is the portion, which produces the useful power delivered by the engine.

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I.C. ENGINE TESTING

Brake Mean Effective Pressure (Pbm):Pim=Pfm+ Pbm

Also, Break Power, bp= kWWhere Pbm = Break mean effective pressure in N/m2.L= Length of stroke in m.A = Area of piston in m2.N= number of working strokes/minK= number of cylinders of the engine.Mechanical Efficiency, ηm==

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I.C. ENGINE TESTING

Piston Speed :It is the average or mean distance travelled by the piston of the engine in one minute.i.e., Piston speed = 2 L.N. m/minWhere, L = Length of stroke (m)And N= Revolutions per minute of the crank

shaft.

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I.C. ENGINE TESTING

Fuel-Air (F/A) or Air-Fuel (A/F) Ratio:The relative proportions of the fuel and air in the engine are very important from the stand point of combustion and efficiency of the engine. This is expressed either as a ratio of the mass of the fuel to that of the air or vice versa.In the SI engine the fuel-air ratio practically remains constant over a wide range of operation. In CI engines at a given speed the air flow does not vary with load, it is the fuel flow that varies directly with load. Therefore, the term fuel-air -

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I.C. ENGINE TESTING

Fuel-Air (F/A) or Air-Fuel (A/F) Ratio:-ratio is generally used instead of air-fuel ratio.

A mixture that contains just enough air for complete combustion of all the fuel in the mixture is called a ‘chemically correct’ or ‘stoichiometric fuel-air ratio’. A mixture having more fuel than that in a chemically correct mixture is termed as ‘rich mixture’ and a mixture that contains less fuel or excess air is called a ‘lean mixture’ or ‘weak mixture’. The ratio of actual fuel-air ratio to the chemically correct -

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I.C. ENGINE TESTING

Fuel-Air (F/A) or Air-Fuel (A/F) Ratio:-fuel-air ratio is called ‘equivalence ratio’ and is denoted by ɸ,ɸ = Accordingly,

ɸ= 1 means chemically correct mixture.ɸ< 1 means lean mixture or weak mixture.

And ɸ> 1 means rich mixture.

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I.C. ENGINE TESTING

Calorific Value (CV) :‘Calorific value’ of a fuel is the thermal energy released per unit quantity of the fuel when the fuel is burned completely and the products of combustion are cooled back to the initial temperature of the combustion mixture. Other terms used for the calorific value are ‘heating value’ and ‘heat combustion’.

When the products of combustion are cooled to 250C practically, all the water vapour resulting from the combustion process is -

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I.C. ENGINE TESTING

Calorific Value (CV) :-condensed. The heating value so obtained is called the ‘higher calorific value’ or ‘gross calorific value’ of the fuel. The ‘lower or net calorific value’ is the heat released when vapour in the products of combustion is not condensed and remains in the vapour form.

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I.C. ENGINE TESTING

Measurement of Air Supply of an I.C. Engine:To measure air supply, the orifice method can be used if pressure pulsations could be damped out by some means. The usual method of damping out the pressure-pulsations is to fit an air box of suitable volume (500 to 600 times the swept volume in single cylinder engines and less in case of multi-cylinder engines) to the engine with an orifice placed in the side of the box, remote from the engine as shown in figure.

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I.C. ENGINE TESTING

Measurement of Air Supply of an I.C. Engine:

Measurement of Airby Air Box Method.

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Measurement of Air Supply of an I.C. Engine:Let a= area of orifice in m3.

Cd= Coefficient of discharge of the orifice.ΔH= Difference of pressure as measured in

cm. of water.Ma= Mass of one cubic metre of air, in kg.Mw=Mass of one cubic metre of water, in

kg.H= Head causing flow through the orifice in

m. of air.

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I.C. ENGINE TESTING

Measurement of Air Supply of an I.C. Engine:V= Velocity of air flowing through the orifice in metre per sec.Q= Discharge of air flowing through the orifice , in m3 per sec.Now, consider one m3 of air at a pressure of ‘p’ N/m2 and absolute temperature ‘T’, Kelvin.Then, applying gas=n

pv=Ma.RTBut v=1m3

Ma=

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I.C. ENGINE TESTING

Measurement of Air Supply of an I.C. Engine:Ma= ( R=287 J/kg-K) ----1

Now, H = X m of airAlso, V = Cd.And Q= a.V

Q=a.Cd. -----2Now, using the equation 1 and 2 the mass of the air supplied can be calculated as follows.

Mass of air supplied = Q.Ma

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I.C. ENGINE TESTING

Air-Standard Efficiency:The air-standard efficiency is also known as ‘thermodynamic efficiency’. It is mainly a function of compression ratio and other parameters. It gives the upper limit of the efficiency obtained from an engine.For engines working on Otto cycle, the air standard efficiency ,

Where, r= Compression ratioAnd

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I.C. ENGINE TESTING

Mechanical Efficiency (:It may be defined as the ratio of the power obtained at the crank shaft, i.e. brake power(bp) to the indicated power (ip).Thus, Mechanical Efficiency () = Mechanical efficiency takes into account the mechanical losses in an engine. Mechanical losses of an engine may be further subdivided into the following groups. (i) Friction losses as in case of pistons, bearings,

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I.C. ENGINE TESTING

Mechanical Efficiency (:gears, valve mechanisms. With the development in the bearing design and materials , improvement in gears etc. , these losses are usually limited from 7 to 9 percent of the indicated power output.(ii) Power is absorbed by engine auxilliaries such as fuel pump, lubricating oil pump, water circulating pump, radiator magneto and distributor, electric generator for battery charging, radiator fan etc. These losses may -

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I.C. ENGINE TESTING

Mechanical Efficiency (:-account for 3 to 8 percent of the indicated output.(iii) Ventilating or faning action of the flywheel. This loss is usually below 4 percent of the indicated output.(iv) Work of charging the cylinder with fresh charge and discharging the exhaust gases during the exhaust stroke. In case of two-stroke engines the power absorbed by the scavenging pump etc. These losses may account for 2 to 6 percent -

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I.C. ENGINE TESTING

Mechanical Efficiency (:-of the indicated power output.

In general, the mechanical efficiency of engines varies from 65 to 85%.

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Indicated Thermal Efficiency (:It may be defined as the ratio of heat converted into indicated work to the heat energy supplied by the fuel, during a specified period of time.So, Indicated thermal efficiency ,(ith)=

= Where, Mf = Mass of fuel supplied to the engine per minute.CV = Lower calorific value of the fuel.

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I.C. ENGINE TESTING

Brake Thermal Efficiency (:It may be defined as the ratio of heat equivalent to brake power (bp) to the heat energy supplied by the fuel during a specific period of time.So, Brake thermal efficiency ,(bth)=

= Where, Mf = Mass of fuel supplied to the engine per minute.CV = Lower calorific value of the fuel.

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I.C. ENGINE TESTING

Brake Thermal Efficiency (:In modern engines, an indicated thermal efficiency of almost 28 percent is obtainable with gas and gasoline spark-ignition engines having a moderate compression ratio and as high 36 percent or even more with high compression ratio diesel engines, i.e. CI Engine.

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I.C. ENGINE TESTING

Relative Efficiency (:The ‘relative efficiency’ or ‘efficiency ratio’, as it is sometimes called, is the ratio of the actual efficiency obtained from an engine to the theoretical efficiency of the engine cycle.So, Relative Efficiency ()=Relative efficiency for most of the engines varies from 85 to 95 % with theoretical air and decreases rapidly with insufficient air to about 75% to 90 % of air.

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I.C. ENGINE TESTING

Volumetric Efficiency (:The ‘Volumetric efficiency’ is measure of the success with which the air supply and thus the charge, is induced into the engine cylinder. It is very important parameter, since it indicates the breathing capacity of the engine.‘Volumetric efficiency’ is defined as the ratio of volume of air induced at ambient condition to the swept volume or it may also be defined as the ratio of actual mass of air drawn into the engine cylinder during a given period of time to -

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I.C. ENGINE TESTING

Volumetric Efficiency (:-the theoretical mass which should have been drawn in during that same period of time, based upon the total piston displacement of the engine and the temperature as well as pressure of the surrounding atmosphere.So, Here,mth= Where is the density of air.

Vs is the swept volume.n is the number of intake strokes per min.

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I.C. ENGINE TESTING

Volumetric Efficiency (:For a four-stroke engine n=N/2 and for a two-stroke engine n=N, where N is the speed of the engine in rev/min. The actual mass is a measured quantity. The theoretical mass is computed from the geometry of the cylinder, the number of cylinders and the speed of the engine in conjunction with the density of the surrounding atmosphere.

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Volumetric Efficiency (:Volumetric efficiency for a naturally aspirated engine is generally about 75%.Mathematically, Volumetric Efficiency,

()=

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Determination of Indicated and Brake Power:In this method, to find out ip an indicator is used to find out the mean effective pressure. This method is used for slow speed engines.An indicator is an instrument which produces a graphic record of the pressure inside the engine cylinder for every position of the piston as it reciprocates. It consists of a small cylinder fitted with a piston, the under side of which is placed in communication with the cylinder. The upper side of the indicator piston is kept in -

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Determination of Indicated and Brake Power:communication with the atmosphere. A helical spring on the top of the piston has one end attached to the piston and the other to the cover of the indicator cylinder through which passes the piston rod which carries a pencil at its upper end. This pencil traces out the indicator (p-V) diagram on the paper.In working with actual engines, it is often desirable to compute ip from a given Pim, i,.e. mean effective pressure and given engine -

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Determination of Indicated and Brake Power:-operating conditions. The necessary formula may be developed from equation of network based on the mean effective pressure and piston displacement. Indicated net work/cycle= Pim X Vs N-m

= Pim X L X A N-m ( Vs = L X A) Indicated net work/min = PimxLxAxn N-mHence, Indicated Power= kWIf, there are ‘K’ number of cylinders, then total indicated power developed by the engine,

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Determination of Indicated and Brake Power:ip= Where, ip = Indicated power (kW)Pim = Indicated mean effective pressure (N/m2)L = Length of stroke (m)A= Area of the piston (m2)n= Number of power strokes per minute. = or for four stroke engine. = Revolutions per minute or N, for two stroke engineK= Number of cylinders.

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Determination of Indicated and Brake Power:And N= Speed of engine in revolutions per minute.Hence, ip= kW (for two stroke engine)And ip= ( for four stroke engine)

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Brake Power (bp):Indicated power is based on indicated net work and is thus a measure of the force developed within the cylinder. More practical interest is the rotational force available at the delivery point, i.e. at the engine crank shaft also termed as drive-shaft and the power corresponding to it. This power is interchangeably referred to as ‘brake power’, ‘shaft power’ or delivered power’. In general, only the term brake power, bp, has been used here to indicate the power actually -

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Brake Power (bp):-delivered by the engine.The power, bp, is usually measured by attaching a power absorption device to the drive-shaft of the engine. Such a device sets up measurable forces counteracting the forces delivered by the engine and the determined value of these measured forces is indicative of the forces being delivered.

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Measurement of bp, using Rope Brake Arrangement:The fig shows rope brake arrangement for the measurement of brake power, bp.

Rope brake Dynamometer

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Measurement of bp, using Rope Brake Arrangement:A rope is wound around the circumference of the brake drum. One end of the rope is attached with balance as shown in fig.

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Rope brake Dynamometer

I.C. ENGINE TESTING

Measurement of bp, using Rope Brake Arrangement:The other end carries the dead weights. The engine is thus run at a ‘constant speed’ which is measured with the help of a tachometer.Now, Let W= Force due to dead weight of the rope brake (N)S= Spring balance reading (N)D= Dia. Of the brake drum (m)d= Dia. of the rope (m)N= RPM of the crank shaft (given by tachometer)

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Measurement of bp, using Rope Brake Arrangement:Then, work done per revolution = Force x Distance

= (W-S) x 2() N-m or JWork done per minute= (W-S) x 2()xN J/min

Work done per sec = J/sec

So, Brake Power= Watts

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I.C. ENGINE TESTING

Measurement of bp, using Rope Brake Arrangement: Brake Power,bp = kW

If the diameter of the rope is neglected, i.e. d=0,

then

Brake Power, bp = kW

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MORSE TEST:It is the method of determining indicated

power (ip) of each cylinder individually, of a multi cylinder IC engine, without the use of an indicator and thus computing the ‘total ip of the engine’ by summing up ip of all the cylinders.

This method is adopted to calculate ip of high speed engines, i.e. where the indicator method is unsuitable.

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Testing of Constant Speed IC Engines for General Purposes According to IS: 1600-1960:-1. Introduction:

This code applies to testing of constant speed reciprocating internal combustion engines of the following types used for general purposes.(a) Compression ignition engines.(b)Carburettor type engines, and(c) Gas engines.This code is not applicable to pressure charged engines, engines for road or rail traction, engines

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Testing of Constant Speed IC Engines for General Purposes According to IS: 1600-1960:-1. Introduction: -engines for ships propulsion or for marine auxiliaries' and engines for aircraft propulsion or aircraft auxiliaries.

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I.C. ENGINE TESTING

Testing of Constant Speed IC Engines for General Purposes According to IS: 1600-1960:-2. General Requirements for Tests: The manufacturer shall supply the performance characteristics of the engine prior to the commencement of the tests.

The engine shall be tested as offered to the purchaser. All parts shall be in stock and all parts essential for engine operation should be included. Accessories used on the engine under test shall be listed.

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I.C. ENGINE TESTING

Testing of Constant Speed IC Engines for General Purposes According to IS: 1600-1960:-3.Preparation for Tests: The engine shall be completely stripped and examined physically so that design features and also the condition of the various parts may be noted before tests are, commenced. After the physical examination the dimensions of the main working parts, listed below shall be checked and recorded.1. Cylinder head.

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I.C. ENGINE TESTING

Testing of Constant Speed IC Engines for General Purposes According to IS: 1600-1960:-3.Preparation for Tests: 2. Valves, valve seats, valve springs and valve guides.3. Cylinder liner.4. Piston Assembly.5. Connecting rod small end big end bearings and connecting rod bolts.6. Crankshaft, including bearings and journals &7. Governer springs.

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I.C. ENGINE TESTING

Testing of Constant Speed IC Engines for General Purposes According to IS: 1600-1960:-

4. Preliminary Run: The engine shall be subjected to a preliminary run of 49 hours at rated speed under operating temperatures as specified by the manufacturer, in non-stop cycle of 7 hours each, conforming to the following cycle, the period of each run being a minimum of one cycle:Load Running time(hr)25% of rated load50% of rated load 275% of rated load 100% of rated load 2

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I.C. ENGINE TESTING

Testing of Constant Speed IC Engines for General Purposes According to IS: 1600-1960:-

4. Preliminary Run: -During the preliminary run, special attention shall be paid to engine vibration and quiteness. The oil pressure shall be checked from time to time.

Oil, coolant and fuel leaks shall be rectifiedand faculty components replaced as may be found necessary. A complete record of such attention and running time of components changed shall be kept.

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I.C. ENGINE TESTING

Test Procedure :-a. Engine adjustment:

The distributor, carburettor or the fuel

pump rack, as the case may be set as its nominal

specified value at idling in contrast to its manual

adjustments for maximum power at each speed.

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I.C. ENGINE TESTING

Test Procedure :-b. Temperature:

The temperature of the inlet air shall be

measured at the entrance of the induction

system.

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I.C. ENGINE TESTING

Test Procedure :-c. Number of Runs:

In every test, a sufficient number of runs

shall be made throughout the speed range. A run

shall be made at the lowest steady at which the

engine operates.

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I.C. ENGINE TESTING

Test Procedure :-d. Duration of Runs:

Performance data shall be obtained under stabilized operating conditions. Durations of the experimental run depends upon two principles:(i) No data shall be taken until load, speed and

temperature have been satabilized.(ii) Recorded data shall be average sustained values maintained over a period of at least one minute, with no significant change occuring during that time.

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I.C. ENGINE TESTING

Test Procedure :-e. Power Test:

For all power tests with results to be plotted versus speed, a single series of stabilized runs at ascending speeds is sufficient. This series of runs should progress continuously, from the lowest to the maximum. If the engine requires to be idled between runs to avoid excessively high temperature, sufficient time should for the engine to reach its stabilized condition before taking readings. The brake load recorded should be steady and constant throughout the run.

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I.C. ENGINE TESTING

Test Procedure :-f. Engine Speed:

Engine speed should be held constant as

possible by means of applied dynamometer load

at wide open throttle or by throttle adjustment

at part load.

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I.C. ENGINE TESTING

Test Procedure :-g. Friction Power:

The friction power test shall, if possible,

follow immediately after the power test. If this is

not possible, the test shall be conducted under

condition similar to those for the power test.

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I.C. ENGINE TESTING

Test Procedure :-h. Fuel Consumption:

Fuel consumption shall be measured

simultaneously with brake power. The fuel

consumption measurement shall not be started

un-till the engine is stabilized.

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I.C. ENGINE TESTING

Observations:-1. Observed brake power is given by the

formula:Brake Power, bp = kW

2. Mechanical efficiency, =

3. Indicated Power, ip= bp + fp

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I.C. ENGINE TESTING

Observations:-4.Specific Fuel Consumption:

Specific fuel consumption shall be computed on the basis of gm of fuel per observed brake power hour.

5. Five Hundred Hour Endurance Test:After completion of the performance test,

the engine shall be run for 500 hours at rated speed in cycles of 16 hours continuous running each cycle being made as follows:

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I.C. ENGINE TESTING

Observations:-5. Five Hundred Hour Endurance Test:- Load Running Time (hrs)100 % of rated load 4 (including warm-up

period)50% of rated load 4110% of rated load 1100% of rated load 350% of rated load 3 At the end of each 16 hour cycle, the engine

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I.C. ENGINE TESTING

Observations:-5. Five Hundred Hour Endurance Test:-shall be stopped and necessary servicing and minor adjustments may be carried out in accordance with the maker’s schedule.

Before starting the next cycle, the engine shall have reached very nearly the room temperature.

One litre sample of the oil drained during each oil change and one litre sample of the fuel used shall be sent to the laboratory for analysis.

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I.C. ENGINE TESTING

Observations:-6. Recheck of Power and Fuel Consumption :

The power fuel consumption shall be determine by repeating the performance test.

7. Final Inspection: At the conclusion of the test, the engine

shall be stripped, its condition noted and the dimensions of the main working parts checked and recorded.

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ASSIGNMENT

Q.1 Explain the following terms:a. Engine continuous power.b. Indicated power.c. Brake power.d. Specific fuel consumption.

Q. 2 What do you mean by(i) Indicated thermal efficiency(ii) Mechanical efficiency(iii) Volumetric efficiency(iv) Overall thermal efficiency.

ASSIGNMENT

Q.3 Discuss any one method to find indicated power.

Q.4 Explain the performance test of an engine according to I.S.

Q.5 Explain any one method of finding brake power.

Q.6 How to measure the quantity of air supplied to an I.C. engine ?

ASSIGNMENT

Q.7 How do you find the ip of a multicylinder I.C. engine without using an indicator?

Q.8 What do you mean by relative efficiency of an engine ? Explain how it is expressed?

Q.9 Distinguish between ip and bp, which is greater ?

Q.10 What for a Morse test is conducted?

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