AE 2202 AERO ENGINEERING THERMODYNAMICS FOURTH UNIT EXAMINATIONS

B.E./B.TECH.DEGREE FOURTH UNIT EXAMINATIONS, SEPTEMBER - 2012

REGULATIONS 2008

SECOND YEAR / THIRD SEMESTER

AE 2202 AERO ENGINEERING THERMODYNAMICS

AERONAUTICAL ENGINEERING

Time: 90 Minutes                                 Date:  22.09.2012                              Maximum:50 marks

ANSWER ALL QUESTIONS

                                                                  PART – A                        (7 x 2 =14 marks)

1.     What are the assumptions made for air standard cycle analysis?

2.     Define Mean effective pressure.

3.     Compare otto, diesel and dual cycles

4.     Mention the various processes of carnot cycle, otto cycle, Diesel cycle, Dual cycle and Brayton cycle.

5.     Define compression ratio and expansion ratio

6.     Define pressure ratio and cut off ratio.

7.     Differentiate petrol and Diesel engines.

                                                      PART – B                       (3 x 12 =36 marks)

8.     Derive the expression for air standard efficiency and mean effective pressure of an constant volume cycle.

or

9.     An engine working on the Otto cycle is supplied with air at 0.1 MPa, 35°C. The compression ratio is 8. Heat supplied is 2100 kJ/kg. Calculate the maximum pressure and temperature of the cycle, the cycle efficiency, and the mean effective pressure. (For air, C_p = 1.005 kJ/kg K, C_v = 0.718 kJ/kg K and R = 0.287 kJ/kg K).       

10.                        Derive the expression for air standard efficiency and mean effective pressure of a constant pressure cycle.

or

11.                        In an air standard diesel cycle, the compression ratio is 16, and at the beginning of isentropic compression, the temperature is 15⁰C and the pressure is 0.1 MPa. Heat is added until the temperature at the end of the constant pressure process is 1480⁰ C. Calculate the cut–off ratio, heat supplied per kg of air, cycle efficiency and the m.e.p.

12.                        Derive the expression for air standard efficiency and mean effective pressure of a mixed cycle.

or

13.                        An air standard dual cycle has a compression ratio of 16, and compression begins at 1 bar, 50°C. The maximum pressure is 70 bar. The heat transferred to air at constant pressure is equal to that at constant volume. Estimate the pressures and temperatures at cardinal points of the cycle, the cycle efficiency and the m.e.p. of the cycle. (For air, C_p = 1.005 kJ/kg K, C_v = 0.718 kJ/kg K and R = 0.287 kJ/kg K).