Rajasthan Technical University 2010 B.Tech Mechanical Engineering I.CEngines & Diesel Power Plant - Question Paper
RTU I.C. Engines & Diesel Power Plant
Rajasthan tech. University
B.tech six sem (Main/back)
Year June 2010 Roll No.__I IOOU no. W !| J I
16E30S0
B-Tech. Vlth Semester (Main/Back) Examination, June - 20101U Mcchanical Engineering
_l.C. Eoglnea & Diesel Power Plant_
Time: 3 Honrs Maximum Marks : 80
Mia. Passing Marks : 24
Instructions to Candidates:
Attempt any five questions selecting one question from each unit. All questions carry equal marks (Schematic diagrams must be shown wherever necessary. Any data you feel missing may suitably be assumed and stated dearly. Units of quantities used/calculated must be stated clearly.)
Uait -1
1. a) Explain with neat sketch the working ofa four stroke S.l. engine. Draw P - V diagram also.
b) The following data relates to a two stroke single cylinder diesel engine using a blend of oil:
Cylinder bore = 200mm
Engine stroke * 250mm
Indicated mean effective pressure 500 N/m*
Fuel consumption per hour = 6.5 kg
Calorific value of fuel = 44000 U/kg
Engine speed = 3 revolution per second calculate the indicated power of engine and its indicated thermal efficiency.
OR
a) How l.C. engines arc classified? Exptain. Draw a chart indicating classification of l.C. engine.
6E30S4/HM/3500 (1) {CoatoL-
b) The following data relates to a four stroke single cylinder gas engine: Cylinder bore and stroke = 500mm and 375mm respectively.
Net load on the brake = 900 N Duration of test 4$ minute Engine revolution = 9450 Engine explosions = 3600 Effective brake tadiut31 800mm Mean effective pressure 600 kPa Gas consumed 9.0 m
Calorific value of gas 18.5 Mi/m1.
Calculate indicated power, brake power & brake thermal efficiency.
Unit-II
2. a) Explain theeffect of engine variables on ignition lag in S.l. engine.
b) Explain compression Swirl. What arc the advantages of compression Swirl in
C.l. engine?
OR
a) Explain the theories of detonation in S.l. engine.
b) Explain the need of additives in the fuels. What are the effects of various additives in engine fuels?
Unit-Hi
3. a) What are basic requirements of a spark ignition system? Describe working of
spark ignition system used in a four cylinder petrol engine.
b) What are the requirements of a diesel injection system? Compare air injection and solid injection
OR
a) Describe the special features of aircraft carburettor. What arc (he drawbacks of modem carburettors?
b) What is the effect of variation of air-fucl ratio on performance of engine? The venturi of a simple carburettor has a throat. Which has diameter of 20mm. The diameter of fuel orifice is 1.20mm and the co efficient of air flow is 0.85 and that of fuel flow is 0.65. If the petrol surface is 5mm below the throat, find the air-fuel ratio for a pressure drop of 0.07 bar.
Take density of air and fuel as 1.2 and 750 kg/m respectively and neglect noslel.P.
6F-W50
Unit-IV
4. a) What arc Ihc functions of the lubrication system used in l.C. engine? Dcscribc.
b) What arc the cffccts of supercharging on power output. Mcchanical efficiency, fuel consumption and cooling of an engine? What arc (he limitations of supercharging?
OR
a) Describe with neat sketch different methods of supercharging. Explain thermodynamics cycle of supercharging.
b) Dcscribc with neat sketch cooling system of a four stroke $.1. engine used in car. What are the components used in cooling system?
Unit - V
5. a) Describe the stages of combustion in a dual fuel engine. When gaseous fuel is
injected in small quantity near top dead centrc.
b) What is (he cffcct of variable compression ratio on power output, thermal load, specific fuel consumption and engine noise?
OR
a) How the performance of a variable compression ratio engine differs from that of a convention engine? Compare.
b) What factors cffcct the capacity of a diesel power plant? Dcscribc safety steps taken in a diesel power plant.
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| Earning: Approval pending. |
