Internal Combustion Engines (ME-501) - Important Questions

Compare Homogeneous Charge Compression Ignition (HCCI) Engine, Lean Burn Engine and Stratified Charge Engines with respect to combustion process, efficiency, emissions and practical usages.

Express the factors affecting delay period in CI engine in detail. Justify it with suitable reason.

Differentiate Otto cycle and Diesel cycle and derive expressions for thermal efficiency, work done and mean effective pressure of the Diesel cycle.

What do you understand by Theory of Carburetion? Explain in detail.

Describe working principle of fuel pump and fuel injectors.

What do you understand by Nozzle? Define its types.

Explain alternative fuels for SI and CI engine. Explain the fuel characteristics of LPG, CNG and hydrogen.

A four-stroke, eight-cylinder engine is tested running at 3600 r.p.m. The inlet air temperature is 5 deg C and the pressure is 760 mm of Hg. The total piston displacement volume is 4066 cm3. The air-fuel ratio is 15:1 and fuel consumption is measured. Determine the volumetric efficiency and air-fuel ratio effects.

Explain the methods of supercharging in IC engines. Also explain the engine modifications required for supercharging.

Explain how electronic control improves boost pressure regulation, engine safety and fuel efficiency?

Discuss the lubrication system of SI engine. Highlight the importance of lubrication and its components.

An IC engine working on Diesel cycle has bore 200 mm, stroke 300 mm. If the clearance volume is 420 cc and fuel injection takes place at constant pressure for 5% of the stroke, find the thermal efficiency of the cycle and the efficiency loss due to delayed cut-off.

Discuss the term knock in SI engine. What are the effects of knock? Also discuss the methods to reduce detonation.

Explain in detail the construction, working and disadvantages of TBI fuel injection system in SI engine.

Describe the term carburetor. Explain the working of Solex carburetor.

Discuss the importance of firing order with respect to engine balancing, vibration reduction, and crankshaft design.