1st Mid FM &HM

KITE COLLEGE OF PROFESSIONAL ENGINEERING SCIENCES

DEPARTMENT OF MECHANICAL ENGINEERING

MID-2 QUESTION PAPER (2-1)

SUB-THERMODYNAMICS

SET-1

1)      a) Air 0.06m³ rigid vessels contains oxygen at a pressure of 1.38 bar and a temperature of 21⁰c. Determine i) quantity of heat energy required to increase its temperature 293⁰c ii) Final pressure of oxygen. Assume c_v =0.986kj/kg k?

b) Determine the amount of heat supplied at constant volume process?

2)      The readings from a sling psychrometer are as follows dry bulb temperature=30⁰c, wet bulb temperature=20⁰c. Barometer reading=740mm of hg. Determine a) Dew point temperature b) relative humidity c) specific humidity d) degree of saturation?

3)      Draw Pv and Ts diagrams for diesel cycle. Derive an expression for ASE of diesel cycle.

4)      Describe reversed Carnot air cycle with Pv and Ts diagrams. Derive an expression for COP of the cycle

SET-2

1)        a) 2 kg of air at a pressure of 875 kN/m² occupies a volume of 0.35m³. The air is then   expanded to a volume of 2 m³ at constant pressure. Find the work done and heat transfer during the process. Take R=o.287 kj/kg k c_v=0.717 kj/kg k?

b) Determine the amount of heat supplied at constant pressure process?

2)      Define a) Degree of saturation b) Relative humidity   c) specific humidity?

3)      Describe Otto cycle with help of Pv and Ts diagrams. Derive an expression for its air standard efficiency.

4)      A machine works on reversed Carnot cycle between temperature ranges of -5⁰c and 20⁰c. determine COP when it working as a) refrigerator and b) heat pump

SET-3

1)      a) 0.1 m³ of air has a pressure of 1.5 bar is expanded isothermally to 0.5 m³. Calculate the final pressure of gas and work done during the process?

b) Determine the amount of heat supplied at constant temperature process?

2)      What is compressibility factor? Write about compressibility chart?

3)      Calculate the thermal efficiency of an Otto cycle working with maximum temperature of 1400⁰c and minimum temperature of 42⁰c. If the compression ratio is 10 and pressure of air at the beginning of the compression is 1.5 bar, then the estimate mean effective pressure.

4)      Describe Bell-Coleman cycle with neat sketches. Derive an expression for COP of the cycle.

SET-4

1)      a) A cycle tire containing air at 500 kN/m² and temperature 25⁰c leaks rapidly such that pressure is reduced to 100 kN/m² under adiabatic condition. Assume adiabatic index is 1.4. Find the temperature of air remained in the tire?

b) Determine the amount of heat supplied for adiabatic process?

2)      Write about Vander Vaal’s equation? Determine the constants values of Vander Vaal’s equation?

3)      Explain sterling cycle and Lenoir cycle with the help of Pv and Ts diagrams.

4)      What are the basic components of vapor compression system? State their functions.