1. The following data were recorded from a test on a single cylinder four-stroke diesel engine.
Cylinder bore =150 mm,
engine stroke =250 mm,
area of indicator diagram =450
length of indicator diagram =50 mm,
indicator spring rating 1·2 mm,
engine speed =420 rpm,
brake torque =217 Nm,
fuel consumption =2·95
calorific value of fuel =44,000 kJ/kg,
cooling water rate of flow 0·068 kg/sec,
cooling water temperature rise 45
specific heat capacity of the cooling water 4·1868 kJ/kg K

Calculate:

The mechanical efficiency

The brake thermal efficiency

The specific fuel consumption

2. The torque delivered by a two-stroke engine is represented by T (l000 300 sin 28 -500 cos 28) N-m where 8 is the angle turned by the crank from the inner-dead centre. The engine speed is 250 rpm. The mass of the flywheel is 400 kg and radius of gyration is 400 mm. Determine:

The power developed,

The total percentage fluctuation of speed,

The angular acceleration of flywheel when the crank has rotated through an angle of 60° from the inner-dead centre.

Discuss the basic requirement of spark-ignition system.

What are the main disadvantages of a battery ignition system How can these be overcome?

What are the functions of lubricating oil in IC engines?

Briefly describe the wet sump water cooling system of a multi-cylinder CI engine.

What are the various methods of measuring indicating power Briefly compare their relative accuracy.

Describe with a sketch, the principle of a hydraulic dynamometer.

6. Discuss the working of an engine on Otto-cycle. In an Otto-cycle the air at 15°C and 1·05 bar is compressed adiabatically until the pressure is 13 bar. Heat is added at a constant volume until the pressure rises to 35 bar. Calculate the air standard efficiency, the compression ratio, and the mean effective pressure for the cycle.

Take Cv =0·718, R =0.287.

7. Write short notes on the following:

Qualitative Governing

Hit and Miss Governing