Question 1: In an engine working on dual cycle the compression ratio is 9. The conditions of air at the beginning of compression are 1 bar, 90o C. Maximum pressure is 6.8 Mpa. Heat supplied is 1700 kJ/kg. Find out:
a) p, V, T at all points.
b) efficiency.
c) MEP.
Qustion 2: In an air standard Otto cycle the condition of air at the beginning is 1 bar, 300 K, compression ratio is 7. The heat supplied is 800 kJ/kg. Determine
a) p, V, T at all points
b) efficiency
c) MEP.
Question 3: The conditions of air at the beginning of compression of a dual cycle are 1 bar, 35o C and 150 litres. The value of the compression is 10 litres and 42 kJ of heat is added at constant volume, 63 kJ of heat is added at constant pressure. Determine
a) air standard efficiency
b) MEP
c) clearance percentage
d) cut-off percentage.
Question 4: Derive an expression for the air standard efficiency of diesel cycle and then deduce it for mean effective pressure.
Question 5: With a neat sketch briefly explain the construction and working principle of a solex carburetor.
Question 6: What are the advantages of lubrication.
Question 7: During a brake, on a four cylinder four stroke engine coupled to a hydraulic dynamometer at constant speed the following readings were obtained. B.P with all cylinders working = 14.7 kW
B.P with cylinder 1 cut off = 10.14 kW
B.P with cylinder 2 cut off = 10.3 kW
B.P with cylinder 3 cut off = 10.36 kW
B.P with cylinder 4 cut off = 10.21 kW
Question 8: A single row impulse turbine develops 132.4 kW at a blade speed of 175 m/s using 2 kg of steam per sec. Steam leaves the nozzle at 400 m/s. Velocity coefficient of the blade is 0.9. Steam leaves the turbine blades axially. Assuming no shock determine the nozzle angle, blade angles at the entry and exit.
Question 9: In a steam nozzle, the steam expands from 4 bar to 1 bar. The initial velocity is 60 m/s and initial temperature is 200o C. Determine the exit velocity if the nozzle efficiency is 92% and the dryness fraction at exit.
Question 10: Derive an expression for critical pressure ratio in a steam nozzle.