Reg. No. ________
Karunya University
(Karunya Institute of Technology and Sciences)
(Declared as Deemed to be University under Sec.3 of the UGC Act, 1956)
End Semester Examination – November/December 2010
Subject Title:
Subject Code:
ADVANCED THERMODYNAMICS
09ME302
Time: 3 hours
Maximum Marks: 100
(Use of steam table and Compressibility chart are permitted)
Answer ALL questions (5 x 20 = 100 Marks)
1.
Compulsory:
2 kg of air at 500 kPa and 800C expands adiabatically in a closed system and its volume is doubled
and temperature becomes equal to that of its surroundings which is at 100 kPa, 5C. Find
a. Change in availability
b. Maximum reversible work
c. Irreversibility
d. Second law efficiency (η)
2.
The Joule–Kelvin coefficient μj is a measure of temperature change during a throttling process. A
similar measure of the temperature change produced by an isentropic change of pressure is
provided by the coefficient μ s , where
μ s=(ðT/ðp)s
Prove that
μ s - μj = V / Cp
(OR)
Obtain the Clapeyron equation from Maxwell’s relations. What are the assumptions involved in the
derivation of Clausius- Clapeyron equation?
3.
4.
5.
Liquid Propane enters air combustion chamber at 250C at a rate of 0.05 kg/min where it is mixed
and burnt with 50% excess air which is at 70C. It is found that 90% of carbon burns to CO2,
remaining 10% forming CO. If the exit temperature of combustion gases is 1500, determine the rate
of heat transfer from the combustion chamber.
(OR)
Determine the enthalpy, entropy, internal energy and fugacity for N2 gas at the pressure of 300 bar
and 450 K using Lee Kesler tables.
7.
Liquid Octane enter the combustion chamber of gas turbine at 1 bar and 250C, it is burned with
stoichiometric air which enters the combustion chamber at the same state. Determine the adiabatic
flame temperature. Neglect K.E and P.E changes.
(OR)
A furnace burns producer gas with 10% excess air at the rate of 7200km3/h and discharge fuel gases
at 400ºC and 760mm Hg. Calculate the flue gas analysis, air requirement and volume of the flue
gases per hour. The gas is supplied from a gas holder and its orsat analysis is: CO 2 4.0, CnHm 0.4,
CO 29.0, H2 12.0, CH4 2.6 and N2 52.0. Ambient temperature is 30ºC and pressure is 760 mmHg
(Assume complete combustion).
8.
a.
6.
9.
Nine particles have speed of 5.0, 8.0, 12.0, 12.0, 12.0, 14.0, 14.0, 17.0 and 20.0 m/s.
i) Find the particles average speed.
ii) What is the rms speed?
iii) What is the most probable speed of the particles?
b. Approximate the air around you as a collection of nitrogen molecules, each of which has a
diameter of 2.0 x 10-10 m.
i) How far does a technical molecule move before it collide with another molecule?
ii) On average, how frequently does one molecule collide with another molecule?
(OR)
Develop the molecular model of a perfect gas. What are the assumptions made in developing the
molecular model of the perfect gas?