 # ME8493 Question Paper Thermal Engineering 1

## Sample Question from ME8493 Question Paper Thermal Engineering 1:

1. An engine working on ideal Otto cycle has temperature and pressure, at the beginning of isentropic compression as 25˚C and 1.5 bar respectively. Find the compression ratio, if γ = 1.4 and thermal efficiency of the engine = 48%. Also find temperature and pressure at the end of compression.
BT-6 ME8493 Question paper Thermal Engineering 1
Creating

2. A diesel engine operating on the air-standard Diesel cycle has six cylinders of 100 mm bore and 120 mm stroke. The engine speed is 1800 rpm. At the beginning of compression the pressure and temperature of air are 1.030bar and 35˚C. If the clearance volume is 1/8th of the stroke volume, calculate (i) the pressure and temperature at the salient points of the cycle (ii) the compression ratio (iii) the efficiency of the cycle and (iv) the power output if the air is heated to 1500˚C. Assume Cp and Cv of air to be 1.004 and 0.717 kJ / kg K respectively.
BT-2 ME8493 Question paper Thermal Engineering 1
Understanding

3. For an engine working on the ideal Dual cycle, the compression ratio is 10 and the maximum pressure is limited to 70 bar. If the heat supplied is 1680 kJ/kg, find the pressure and temperatures at the various salient points ofthe cycle and the cycle efficiency. The pressure and temperature of air at the commencement of compression are 1 bar and 100˚C respectively. Assume Cp=1.004 kJ/kg K and Cv= 0.717 kJ/kg K for air. ME8493 Question paper Thermal Engineering 1

4. The compression ratio of an engine is 10 and the temperature and pressure at the start of compression is 37˚C and 1 bar. The compression and expansion processes are both isentropic and the heat is rejected at exhaust at constant volume. The amount of heat added during the cycle is 2730 kJ/kg. Determine the mean effective pressure and thermal efficiency of the cycle if (i) the maximum pressure is limited to 70 bar and heat is added at both constant volume and constant pressure and (ii) if all the heat is added at constant volume. In this case how much additional work per kg of charge would be obtained if it were possible to expand isentropically the exhaust gases to their original pressure of 1 bar? Assume that the charge has the same physical properties as that of air. ME8493 Question paper Thermal Engineering 1

 Subject name Thermal Engineering 1 Short Name TE 1 Semester 4 Subject Code ME8493 Regulation 2017 regulation