Reg. No.
B.E. B.Tech. DEGREE EXAMINATION, MAY 2017
Third Semester
Mechanical Engineering
01UME303 ENGINEERING THERMODYAMICS
(Use of steam tables, charts may be permitted)
(Regulation 2013)
Duration: Three hours Maximum: 100 Marks
Answer ALL Questions
PART A (10 x 2 20 Marks)
1. Define thermodynamic system.
2. What is heat?
3. What do you mean by "Clausius Inequality"?
4. State Zeroth law of thermodynamics. What is its application.
5. What do you understand by pure substance? Give some typical examples?
6. Name the different processes of Rankine cycle on T-S diagram.
7. State Gibbs function.
8. What are the unique features of Van der Waals equation of state?
9. State Dalton's law of partial pressure.
10. What is dew point temperature? How is it related to dry bulb and wet bulb temperature at the saturation condition?
Question Paper Code: 31733
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PART B x 16 80 Marks)
11. A piston and cylinder machine contains a fluid system which passes through a
complete cycle of four processes. During a cycle, the sum of all heat transfer is
-170 kJ. The system completes 100 cycles/min. Complete the following table
showing the method for each item, and computes the net rate of work out put in kW.
Process Q Q E
a b 0 2,170
b c 21,000 0
c d 2,100 36,600
d a

Or
Derive the general energy equation for a steady flow system and apply the
equation to a nozzle and derive an equation for velocity at exit.
12. Two reversible heat engines A and B are arranged in series. Engine A rejecting heat
directly to engine receives 200kJ at a temperature of 421°C from a hot source,
while engine B is in communication with a cold sink at a temperature of 4.4°C. If
the work output of A is twice that of find The intermediate temperature between
A and B the efficiency of each engine The heat rejected to the cold sink.
Or
A reversible engine operates between a source at 972oC and two sinks, one at
127oC and another at 27oC. The energy rejected is same at both the sinks. What is
the ratio of heat supplied to the heat rejected? Also calculate the efficiency.
13. A vessel of volume 0.04 m3 contains a mixture of saturated water and saturated steam
at a temperature of 250oC. The mass of the liquid present is 9 kg. Find the pressure,
the mass, the specific volume, the enthalpy, the entropy and the internal energy of the
mixture.
Or
Steam enters the turbine at 3 MPa and 400oC and is condensed at 10 kPa. Some
quantity of steam leaves the turbine at 0.6 MPa and enters open feed water heater.
Compute the fraction of the steam extracted per kg of steam and cycle
thermal efficiency.
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14. Explain the flow process of a real gas through a throttle value. Derive the expression for Joule Thomson coefficient and get its value for an ideal gas.
Or
Derive Maxwell's equations.
Prove Tds=Cv dT+ dV.
15. Explain the following:
Heating and humidification
Adiabatic mixing of two streams.
Or
In an adiabatic mixing of two streams, derive the relationship among the ratio of mass of streams, ratio of enthalpy change and ratio of specific humidity change.
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