Hall Ticket No Question Paper Code: AME007
INSTITUTE OF AERONAUTICAL ENGINEERING
(Autonomous)
B.Tech IV Semester End Examinations Supplementary) July, 2018
Regulation: IARE R16
APPLIED THERMODYNAMICS
Time: 3 Hours Max Marks: 70
Answer ONE Question from each Unit
All Questions Carry Equal Marks
All parts of the question must be answered in one place only
UNIT I
1. Explain the working of a 4 stroke CI engine with the help of valve timing diagram.
Discuss the requirement of cooling and lubrication in an IC engine?
2. Describe the working principle of a 2-stroke SI engine with help of neat diagram.
What is the function of fuel feed pump of CI engine fuel injection system and explain its working
in detail.

UNIT II
3. What is meant by abnormal combustion and explain the phenomena of knocking in SI engine?

Explain the effect of various engine parameters on knocking characteristics of SI engine.
4. Detailed the stages of combustion in CI engine with help of diagram.
What are the important qualities of SI engine fuel and explain how to rate it?
UNIT III
5. What are the various methods to determine the brake power of an IC engine and explain about
Prony brake method?
The following details were noted in a test on a 4 cylinder four stroke engine, diameter 100
mm; stroke 120 mm; speed of engine 1600 rpm; fuel consumption 0.2 kg/min; calorific
value of fuel is 44000kJ/kg; difference in tension on either side of the brake pulley is 40 kg; brake
circumference is 300 cm. if the mechanical efficiency is 80% calculate, brake power, indicated
power, frictional power, brake thermal efficiency and indicated thermal efficiency.
6. Differentiate fan, blower and compressor with its operating conditions.
A test on a single cylinder, 4 stroke oil engine having a bore of 15 cm and stroke 30 cm gave
the following results: speed 300 rpm; brake torque 200 Nm; indicated mean effective pressure
7 bar; fuel consumption 2.4 kg/hour; cooling water flow 5 kg/min; cooling water temperature
rise 350C; air fuel ratio 22; exhaust gas temperature 4100C; barometer pressure 1 bar; room
temperature 200C. Calorific value of fuel is 42000 kJ/kg; Specific heat of exhaust gas 1 kJ/kg
and R=0.287kJ/kg.K. Draw up a heat balance in terms of kJ/min.
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UNIT IV
7. Classify rotary compressors and explain the working principle of roots blower.
A centrifugal blower compresses 4:8m3/s of air from 1 bar and 200C to 1.5 bar. The index of
compression is 1.5. The flow velocity at inlet and outlet is same and equal to 65 m/s. The inlet
and outlet impeller diameters are 0.32 m and 0.62 m respectively. The blower rotates at 8000
rpm. Calculate the work done and blade angles at inlet and outlet. Assume that there is no
diffuser and total pressure rise takes place in impeller itself.
8. Describe the construction and working of axial flow compressor.
Write short notes on the following related to axial flow compressor
i. Degree of reaction,
ii. Polytropic efficiency,
iii. Flow coefficient
iv. Work coefficient
UNIT V
9. What is an air refrigeration system and how the Bell-Coleman air refrigeration system works?
Explain in detail.
A refrigerant machine operates between and 300C and circulates the refrigerant at the
rate of 4.5 kg/min. The temperature of refrigerant gas after is entropic compression is 750C.
Determine
i. COP of the system
ii. Ice produced in kg/hour from water at 200C and ice at
iii. Quantity of refrigerant entering the compressor in m3/min.
Take Specific heat of refrigerant gas 2.82 kJ/kg K
Specific heat of ice 2.1 kJ/kg K
Specific heat of water 4.2 kJ/kg K
Latent heat of ice 336 kJ/kg
Use the refrigerant properties listed in Table 1.
Table 1
Ts Specific volume m3 kg Enthalpy kJ/kg Entropy (kJ/kig
vf vg hf hg sf sg
-15 0.00152 0.509 112.3 1426 0.457 5.549
30 0.00158 0.111 32.31 1469 1.204 4.984
10. Draw the neat compact diagram of vapor absorption refrigeration system and explain its working.

Name three refrigerants that are commonly used in commercial refrigerants. Discuss their merits
and demerits.