STUPIDSID
Solve any one question from Q1 and Q2
1 (a)
Explain function, material and manufacturing method of the following components:
1) Piston
(2) Cylinder
3) Connecting rod
(4) Piston rings
(5) Crankshaft
(6) Camshaft.
1) Piston
(2) Cylinder
3) Connecting rod
(4) Piston rings
(5) Crankshaft
(6) Camshaft.
6 M
1 (b)
Draw and explain with neat sketch Simple Carburettor.
6 M
2 (a)
Draw and explain port timing diagram for 2-stroke petrol
Engine.
6 M
2 (b)
Describe with neat sketch stages of combustion in S.I. Engine with the help of P-θ diagram.
6 M
Solve any one question from Q3 and Q4
3 (a)
Explain with neat sketch common rail diesel injection.
6 M
3 (b)
A 4-S cycle petrol engine has 6 single acting cylinders of 7.5 cm bore and 9 cm stroke. The engine is coupled to a break having torque arm radius of 38 cm. At 3300 RPM with all cylinders operating, a net brake load is 324 N. When each cylinder in turn is cut-off average net brake load produced at the same speed by the remaining 5 cylinders is 245 N. Estimate indicated mean effective pressures. With all cylinders
operating, the fuel consumption is 0.3 kg/min. Fuel calorific value 42000 kJ/kg. The jacket water flow rate and temperature rise are 65 kg/min and 12°C. On test the engine is enclosed in thermally and acoustically insulated box, through output drive, water, fuel, air and exhaust connections pass. Ventilation air blown up through the box at the rate of 14 kg/min enters
at 10°C and leaves at 55°C, draw a heat account of the engine stating the items as % of fuel.
6 M
4 (a)
Differentiate between knocking in SI and CI engine.
6 M
4 (b)
The air flow to 4 cylinder 4-S gasoline engine was measured by means of 8 cm diameter sharp edge orifice with Cd = 0.65. During a test the following data was recorded: Bore = 10 cm
Stroke = 15 cm
Engine speed = 2500 rpm
Brake power = 36 kW
Fuel consumption = 10 kg/hr
Calorific value of fuel = 42 MJ/kg
Pressure drop across orifice = 4 cm of water
Atmospheric temperature and pressure are 17°C and 1 bar resp.
Calculate :
(1) Brake thermal efficiency
(2) Break mean effective pressure
(3) Volumetric efficiency based on free air condition.
Stroke = 15 cm
Engine speed = 2500 rpm
Brake power = 36 kW
Fuel consumption = 10 kg/hr
Calorific value of fuel = 42 MJ/kg
Pressure drop across orifice = 4 cm of water
Atmospheric temperature and pressure are 17°C and 1 bar resp.
Calculate :
(1) Brake thermal efficiency
(2) Break mean effective pressure
(3) Volumetric efficiency based on free air condition.
6 M
Solve any one question from Q5 and Q6
5 (a)
Explain in brief significance of Bharat Stage Norms for pollution
control.
6 M
5 (b)
Describe with schematic diagram working of starting system.
7 M
6 (a)
Explain with neat sketch Evaporative Loss Control system.
6 M
6 (b)
Enlist different types of lubrication system and explain with
neat sketch wet sump lubrication system.
7 M
Solve any one question from Q7 and Q8
7 (a)
Explain vane type compressor with neat sketch and P-V diagram.
6 M
7 (b)
A reciprocating compressor of single stage, double acting type delivers 20 m 3 /min when measured at free air condition of 1 bar, 27°C. The compressor has compression ratio of 7 and
the conditions at the end of suction are 0.97 bar, 35°C. Compressor
runs at 240 r.p.m. with clearance volume of 5% of swept volume.
The L/D ratio is 1.2. Determine the volumetric efficiency and
dimensions of cylinder and isothermal efficiency taking the index
of compression and expansion as 1.25. Also show the cycle
on P-V diagram.
7 M
8 (a)
Explain the methods of improving efficiency of reciprocating compressors.
6 M
8 (b)
A reciprocating compressor of single stage and double acting
type is running at 200 r.p.m. with mechanical efficiency of
85%. Air flows into compressor at the rate of 5 m3 /min measured
at atmospheric condition of 1.02 bar, 27°C. Compressor has compressed air leaving at 8 bar with compression following
polytropic process with index of 1.3. Compressor has clearance
volume of 5% of stroke volume. During suction of air from
atmosphere into compressor its temperature rises by 10°C. There
occurs pressure loss of 0.03 bar during suction and pressure
loss of 0.05 bar during discharge passage through valves. Determine
the dimensions of cylinder, volumetric efficiency and power input
required to drive the compressor if stroke to bore ratio
is 1.5.
7 M
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