Internal Combustion Engines — Summer 2024

Define Mechanical Efficiency, Mean Effective Pressure and Stoichiometric air-fuel ratio.

Compare two-stroke engine with four stroke engine.

Explain the Methods of measuring Friction Power and explain any one of them in details.

What is MPFI system?

State functions of lubrication. Also write desirable properties of lubrication oil.

A 4-cylinder 4-stroke petrol engine develops 30 kW at 2500 rpm. The mean effective pressure on each cylinder piston is 8 bar and mechanical efficiency is 80%. The stroke to bore ratio is 1.5. Determine diameter and stroke of each cylinder. Also determine fuel consumption of the engine if brake thermal efficiency is 30%. Take calorific value of fuel as 44 MJ/kg.

What is supercharging and Turbo charging? Discuss the effects of supercharging on engine power output and mechanical efficiency.

What is firing order? Explain its importance and significance in case of I.C. Engine.

Explain Octane and Cetane number of fuel.

Explain the phenomenon of knock in case of S.I Engine with neat sketch.

Distinguish between physical delay and chemical delay in case of C.I. Engine.

Explain Euro VI norms with the practical significance.

What are major sources of air pollutants? What pollutants are emitted by Automobiles?

What is variable compression ratio engine? List methods to vary the compression ratio.

Define calorific value of fuel. How is it measured?

Explain various stages of combustion in C.I. Engine.1

What are the knock limiting parameters in S.I.engine?

Write brief note of nozzles used in C.I. Engine.

Explain Ignition Requirement. Also Give Types of Ignition Systems and explain in detail any one of them.

What do you understand by zero emission vehicle?

Compare wet sump and dry sump lubrication systems.

What do you understand by the heat balance sheet of an I.C.Engine? Represent the generalized heat balance sheet it in the table.

What is Dissociation? What are its effects

What is catalytic convertor? List various types used in the I.C engine.

What are the methods used for governing of I.C. engine? Explain any one with neat sketch.