7/29/2019 Automotive Electrical and Electronics Unit IV

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UNIT IV

ME 51 THERMAL ENGINEERING

Part A

1. What is the function of Camshaft and Crankshaft?2. List out the effects of Detonation?3. What are the various methods to determine the FHP of the engine?4. What re the basic requirement of the fuel injection system of a diesel engine?5. What is meant by compensation in carburetor?6. List out the various circuits available in Solex Carburetor?7. Compare CI engine and SI engine?8. Which is better efficient two stroke or four stroke engines?9. What do you mean by Scavenging in IC engines?10.

Define Mean effective pressure?

Part B

11) Explain why cooling is necessary in IC engine? With neat sketches describe the working of

water cooling system used for a multi cylinder engine. Why should a pump and thermostat be

provided in the cooling system of an engine?

12) The following details were noted in a test on a four cylinder, four stroke engine,

diameter=100mm; stroke=120mm; speed of the engine =1600rpm; fuel consumption=0.2kg/min;

fuel calorific value =44,000KJ/kg; difference in tension on either side of brake pulley=40kgf;

brake circumference is 300cm. If the mechanical efficiency is 80%, calculate:

a. Brake thermal efficiency,b. Indicated thermal efficiency,c. Indicated mean effective pressure andd. Brake specific fuel consumption

13)i)Compare 4-stroke and 2-stroke cycle engines.

ii) Explain with a neat sketch the non-exhaust emission from a vehicle.

14)Describe the working of the simple carburetor and derive the expression for the Air-fuel ratio.

15) With neat sketch explain the components of an IC engine.