Internal Combustion Engines — Winter 2022

Define the following terms i. Heat engine ii. Compression ratio iii. Brake thermal efficiency

Compare the spark ignition engine with compression ignition engine.

Explain in detail the phenomenon of dissociation.

Define the following terms i. Octane Number ii. Cetane Number iii. Highest Useful Compression Ratio( HUCR)

Describe in brief the splash lubrication system

Explain with the neat sketch the construction and working of Junker’s gas calorimeter.

Explain the following terms i. Enthalpy formation ii. Enthalpy of reaction iii Adiabatic flame temperature.

State the methods and devices for emission control from S I Engines.

Explain requirement of air fuel ratio for maximum power and maximum efficiency.

Asimple jet carburetor is required to supply 5 Kg of air per minute and 0.5 Kg of fuel per minute having density 740 Kg/m3. The air initially at 1.05 bar pressure & 27⁰C temperature. Calculate the throat diameter of the choke for a flow velocity of 90 m/s. The velocity co-efficient is 0.8. Take C =0.7 kJ/kg.Kand R= 0.287 kJ/kgK v

State the functions of IC engine lubrication system.

Justify the necessity of I Cengine cooling.

Explain the construction and working of bosch fuel injection pump used for Diesel engines.1

State the effects of supercharging on following parameters of C I engines. i. Brake power ii. Mechanical Efficiency iii. Knock tendency

Discuss the advantages and disadvantages of super charging.

Explain with neat sketch Hit and Miss governing

State the objectives of supercharging.

Compare the supercharging with turbocharging,

Explain with neat sketch working of coil ignition system.

Enlist the factors to be considered while selecting the site for a Diesel Engine power plant.

Apetrol engine working on Otto cycle has a compression ratio 8. The specific heat at constant volume increases by 2 %. Calculate the change in air standard efficiency of the cycle. Take C =0.7 kJ/kg.Kand R= v 0.287 kJ/kgK as an average value.

Descrbe with sketch the different stages of combustion in C Iengine.

“ S Iengine are quantity governed and C Iengine are quality governed engines” Comment on this statement.

Describe in beif the “ Morse test”. also state its limitations.

The following data were recorded while conducting a Morse test on 4- cylinder, 4- stroke petrol engine at particular Costant speed Brake power with all cylinder working---- 21 kW Brake power with no.1 cylinder cut off ---- 14.8 kW Brake power with no.2 cylinder cut off ---- 14.5 kW Brake power with no.3 cylinder cut off ---- 14.6 kW Brake power with no.4 cylinder cut off ---- 14.75 kW Estimate the indicated power of the engine and its mechanical efficiency.