. CHHATTISGARH SWAMI VIVEKANAND TECHNICALuNrvERSrTY, BHTLAI (C G)

Semester: Vth Branch: ilechanical Engg.

SubJect lnternal Gombustion Engines

UNIT - Ilntroductionlntroduction of lnternal and external combustion engine and their comparison, four stroke cycle S,l. and C.l, engine,two stroke engine, comparison of four stroke and two stroke engines, comparison of S.l. and C.l. engine,classification of l.C. Engine, Valve timing diagram for S.l. and C.l. engines, effect of valve timing and engine speedon volumetric effrciency, reasons for ignition and injection advan@, dual fuel, multi-fuel and Wankel Rotary engine.GyclesReasons for deviation of actual cycle from air standard cycles, variation specific heats and cycle analysis, fuel aircycles and their analysis, actual cycles and their analysis.Purpose and Thermodynamic cycle of supercharging.

UNIT-IIFuelsBasic requirement of l.C. Engine fuels, requirement of an ideal gasoline, structure of petroleum, effect of fuelstructure on combustion, volatility of liquid fuels, effect of volatility on engine performance for starting, vapour lock,acceleration, percolation, carburetor icing, and crank case dilution.CombustionDetermination of stoichiometric air fuel ratio, fuel-air and exhaust gas analysis for a given combustion process.Combustion in S.l. and G.l. engines, Detonation,. Pre-ignition , Knocking, Antiknock rating of fuelsOctane number, criticalcompression ratio, HUCR, perbrmance number, Cetane number. Dopes

uNlT-lllGarburetorProperties of air-petrol mixtures, mixture requirement, simple carburetor, limitation of simple carburetor, modemcarburetor, Main metering system, ldling system, Economizer system, acceleration pump and cold starting system.Nozzle lip, venturi depression, calculation of fueljet and venturi throat dia for given air fuel ratio.Petrol lnjection system, electronic fuel injection, advantiage and disadvantage of petrol injection.

UNIT.IVlgnition SystemBattery and magneto ignition system and their comparative study, spark plug heat range, electronic ignition system,firing order, lgnition timing, centrifugaland vacuum ignition advanee.lnfection SystemRequirement, type , fuel pump, type of fuel injector, type of nozzle, atomization, spray penetration and spraydirection, multiple point fuel injection system.Cooling SystemCooling requirement, air cooling, llquid cooling, type of liquid cooling system, advantage and disadvantage of aircooling and water cooling system, Antifreeze mixture.Lubrication SystemFunition of lubricating system, properties of lubricating oil, wet sump, dry sump and mist lubrication system.W{ecessity of governing, various methods of goveming.

, UNIT -V,,-,' Testing and Performance

Performance parameters, rneasurements of brake power, indicated power, friction power, fuel and air consumption,.,gIhaust gas calorimeter, calculation of various performance pammeter, heat balance sheet.Porformance cunent for S.l. and C.l. Engine with load and sfeed.Emission and PollutionSl Engine and Cl Engine emiesionE and its control and comparison. Effect of pollution on Human health and biosphere,

{-'ti vT'LJ Code:h{II09512

B. Tech.: Fifth Semert"., APtil-May 2010 ExaminationSubject: Internal Combustion Engines

Branch: Mechanical Engineering

Time: Three Hours Max. Marks: g0' Min. Marks:28

Note: Atterrpt an)' five questions. All question carry equal marks. Assunre suitable data if any.

rf-\Pl)Jq Dilferentiate Actual cycle and Air- standard cycle with the help of PV diagram.\_,./

. W What do you understand by "Ramming Effect,'?v '-..'- -J --------.....o

What should be the qualities in S. I. Engine fuel?1

How the following variables can reduce the detonation in a S. I. Engine?(i) Spark tirning,(ii) Combustion chamber wall ternperature.

Describe with the help of neat sketch the working of simple carburetor.

The diameter ofthe venturithroal of a 4-cylinder,4-stroke, engine carburetor is 2cnrs. Theengine runs at l500r.p.m..The*diim&ir ar\o ttrot e,6r"the engirie-cylinder are!.ffi;l2ctus respectively. The volurnetric efficiency of ihe engine is'gd%. niO the sirction headrequired at tlre \/enturi throat in cm of water

{a} Neglect the effect of air eompressibili4, and n+ril e !ip,

{b) lf nozzie lip is 6mmand the pr=75A kg/m3(c) Find A:F ratio if the Cor:0.65 and fuel nozzle diameter is 7.Ztrurl.take Cou:O.85 and

Pa =1.3 l<g/m3.

Why the cooling is essential in I. C.I . Cl. Engine.

r)?\<s (a)

{br

r0

6

()o

8

6

.*".wJ*{

-*'flKr*V@#

r-ffi

rfPF\(Q5 /(a)\_-/

10

BEngine? Explain the various method of cooling in!;.

What do 1'6Lr understand by Air and Solid injection systenr? Explainsolid injection system.

Drarv the following performance curve for S. I. Engine:(l ) Errgine speed vs torqLle,b h p .

(2) E,ngine speed vs b. s" f. c. and f. c. (fuel consllmption)(3) Errgine speed vs air consumption and charge"

the various types of,4

ili g''

1rr"l,

*+5f The following data were obtained in a trial on a 4-stroke gas engine when trial is conductedfur one hour.-ltesolutions I 6000 ,t*

-Missed cycle 600 'rA

-l.let trral<e load 1600 N 'i''"i

-[]ralie circumfbrence 4 rn-Cas conslutlption 2200 liters-N4EP I bar: '

T'{tr

*r

il

-C.V. o1'gas 20 kj/liters.-Take diameter and stroke of cylinder as 25 cm and 40 cm respectively.Find : I.P., 8.P., bsfc, qi,6 and 11,

What are the main pollutant emitted by petrol engine? Explain the various methods bywhich S. l. Engine emission can be controlled.

What are the basic requirement of a catalytic converter ?

" - *L1,:-- --

tfl

(t, )

I

i

I

1

I

I

I

I

I

l

II

IJ

I

I

i

I

I

i

I

IiI(

I

I

I

I

l

I

t

viI

I

II

i

I

I

I

I

I

4d\ )

\J ],

{ lsv"$'B '

'f irne: 'fhree FIours

B. T'efih": Fiffh $iemesten Nov-Dec 2t)09 ExaminationSubject: trntermal Cornbustion Engines

Eranch : Nlechanical Engineering

{'os$e : &€ F,{}$512

Ilfax. Marks: 80NIin" &larks:28

Note: Attempt any five questions. All question carry equal marks. Assume suitable data if any.

Qr (a) Why do we elinrinate the suction and exhaust stroke in the ldeal thermodynamic analysisof I. C. Engine?

(b)

{J2 (ai

Q3 (a)

(b)

Q4

Draw the valve timing diagram of low speed and high speed S. I. Engine and explain it.

What should be the qualities in C. l" Engine fuel?

Describe the various types of abnormal combustion.

What do you understand by supercharging ? What are the advankges of a superchargedengine.

A four cylinder,4-stroke ,engine running at 2000r.p.m. is provided with a carburetor whoseventuri throat is 3cm.the volumetric efficiency of the engine is70o/o.find the suction at

throat of the venturi .Take p. =1.2 kg/mr and Cou:0.8 and atmospheric pressure is I .013bar. The diameter and stroke of the engine cylinder are l0cms and l2cms respectively.

Why the lubrication is essential in l. C. Engine? Explain the various types of lubricatingsystem in I. C. Engine.

What are the functions of Nozzle?

Explain the effect of improper exhaust system design on the engine performance with the

Describe with the help of neat diagranr the working of after bunrer to control exhaustemission in I. C. Engine.

Wlrat are tlie effects of different pollutants on hurnan and plant Iifb?

l2

I

I

(a)

l0

I

(b)

Qs (a)help of indicator diagram.

_

,1ffit't" following data was collected during the trial on a single cylinder, 4 stroke oil engine.\)U Diameter of the cylinder 250 qm, piston stroke 600 mm, area of the indicator diagram 4.5cm2,length of indicator diagram 7.1 cm, spring constant 8.5 barlcm2-cm, of compression,speed of the engine 350 rpm, load on the hydraulic dynamometer 980 N, dynamometerconstant I 1800 when load is in Newton and speed is in rpm. F'uel used I l.l kg/hr, C.V. offuel used 42000 kj&g, cooling water circulated 18.3 kg/min, rise in temp. of cooling water25"C.The mass analysis of oil used is given as carbon 857o, hydrogen 13,5olo, incombustiblet.5%.J'he volume analysis of exhaust gases is given as CO28Yo,OzllYo,Nz 8l%o by difference.Temp. of exhaust gases 400" C, Cr.e I kj/kg K, ambient temp. 25"C, partial pressure ofsteam in exhaust gases.035 bar, Cp of superheated steam 2 kj/kg K.Draw heat balance sheet on minute basis and percentage basis. l0

{Xr {a)

alh)

(srs k , r!r"f7?' mcah I L" u&s . c9t4

6o T1/LcuI.- f"'14

Code:ME0B 512

"T0

csvTtl

nationNov*Dec ?S0S ) ExarnCombustion Engines

nnicsl Engineering

Fifth Semester (Subject: Internal

Branch: Meeh

B. Tech.:

Time: Three Hours i *ax. Marks: g0

fl tvtin. Marks:28

Note: Attempt any five questions. All question carry equal marks. Assume luitable data if any.

Ql (a) Why the study of Air-standard Cycle is essential in I. C. Engine? il *$

(b) Differentiate Actual cycle and Air- standard cycle with the help

tfV Oiug*r. tz

Q2 (a) Explain the following terms: il

(i) Vapor lock fl +(ii) lcing

{

il

(b) "Volatility is the most important property of the gasoline"justify ftt nI

Q3 (a) What basic functions must the carburetor fulfill? il 4

@rft6-cylinder,4-stroke engine,8cm in diameter andl2cmstroke ru{r at:ooo r.p.m.. Thev (-volumetric efficiency of the engine is 80%.lf the maximum head ga6ing the flow islimited to llJg5qrnlof mercury, find the throat diameter of the i,pnturi required. Also

&r*]'.oiffieifthec1esiredA:Fratioi'.rl'r'li;;d;};llowingC6a:0.9,C6i:0.7,p"=1,3kg/m3 andp;720kg/m3. j t,

Q4 (a) Cive the comparison between baltery and magneto ignition ,yu.,$. 6fl

(b) Why the lubrication is essential in I. C. Engine? Explain the varioflrs types of lubricatingf rosystem in L C. Engine. fl

Q5 (a) Explain the effect of improper intake system design on the engineNperformance with thehelp of indicator diagram

f; 6,.

(b) A single cylinder, 4-stroke cycle engine work on diesel cycle. fh{ following observationare made during the test at full load: t

Area of indi cator :3cm2 ,Length of the diagram = 4cms. spring'jonrranr = .l0 bar/cm^ :ilt$r Speed of the engine : 400r.p.m., Load on the brake: 380N,sprin$reading : 50N.

Dia, Of brake drum: l20cms., Fuel consumption = 2.8kg/hr,CY{f fu"f: 4{000kj/kg,

Dia. Of cylinder = l6cms, Stroke lengh = 20cms il

Find: (i) F,H.P. (ii) Meoh. Efficiency (iii) Brake thermal.fn[i"n.v. l0I

(a)

(b)

Q6

to control the r;xlraust

Ii)

pI,AAL f"{4

CSVTU Code:MEO7Slz]|/IB.Tech (Fifth Semester) Examination Dec.-Jan.2007-08

Subject: Internal Combustion EnginesBranch: Mechanical Engineering

Tirne: Three Hours Max Marks:80Minimum Marks:28

Note: Attempt any five questions. All question carry equal marks. Assumesuitable data if any.

Q.1 2,@). Why actual cycle differs from Air-Standard cycle? List out the major losses. 08

1(b) Draw the valve timing diagram of Low and High speed S.I. engines and give thereasons for the deviation. 08

Q.2 (a) What do you understand by abnormal combustion in case of S.I. Engines?: Explain different types of abnormal combustion.

1 (b) Explain the following terms:

(i) Crank case dilution.

(ii) Vapour lock.

Q.4 . (u). What do you understand by Air and Solid injection system? Explain the various, f?.- types of solid injection systems.'(t. a

*W Give the c_omparison between Battery and Magneto lgnition system.

Q.5 Draw the following performance curves for S.I. Engines and explain them.

(i) Engine speed Vs Torque, B.H.P.,

(ii) Engine speed Vs b.s.f.c. and fuel consumption (f.c.)

(iii) Engine speed Vs Air consumption and charge.

Q.6 (a) Define with the help of neat sketches the following methods used to control theexhaust emission in S.L engines.(i) After bunner.

(ii) Exhaust manifold reactor.

-,(V..u Write the energy balance equation for I.C. Engine and explain each term in\L{7 details. 06.dlV/'/

08

08

Q.3 (a) - A four cylinder, 4 stroke engine running at 2A00 RPM in provided with .1

'/' carburettor where venturi throat is 3crn. find the suction at the throat assuming

Lo the Vol. efficiency of the engine is 70Yo take. pu : 1.2 kglm3 and C6u: 0.8 and- Pu,,n : 1.013 bar. Stroke and diameter of engine cylinder xe 12 cm and l0 cm

t2a. respectively.

$)-r.What basic function must thb carburettor fulfil? 04

10

06

16

10