Download AKTU (Dr. A.P.J. Abdul Kalam Technical University (AKTU), formerly Uttar Pradesh Technical University (UPTU)) B-Tech 4th Semester (Fourth Semester) 2018-19 RME403 Applied Thermodynamics Question Paper
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RME403
Page 1 of 2
Printed Pages:02 Sub Code: RME403
Paper Id: 140268 Roll No.
B. TECH.
(SEM IV) THEORY EXAMINATION 2018-19
APPLIED THERMODYNAMICS
Time: 3 Hours Total Marks: 70
Note: Attempt all Sections. If require any missing data; then choose suitably.
SECTION A
1. Attempt all questions in brief. 2 x 7 = 14
a. What do you mean by air standard cycles? Discuss its? significance.
b. Define the following:
Brake power, Indicated power, Brake mean effective pressure, and Indicated mean
effective pressure.
c. Enlist the requirements of a good boiler?
d. What do you mean by supersaturated flow?
e. Give limitations of Carnot vapour power cycle and explain how Rankine cycle helps in
overcoming them.
f. Differentiate between impulse and reaction steam turbines.
g. Explain the significance of choked flow in a nozzle.
SECTION B
2. Attempt any three of the following: 7 x 3 = 21
a. Derive an expression for air standard efficiency of Otto cycle in terms of compression
ratio.
b. A steam engine working on Rankine cycle operates between 1.96 MPa, 250?C and
13.7 kPa. If engine consumes steam at the rate of 0.086 kg per second, determine
Rankine cycle efficiency, neglecting pump work. Also, find Rankine cycle efficiency
considering pump work..
c. A boiler generates 7.5 kg of steam per kg of coal burnt at a pressure of 11 bar from
feed water having a temperature of 70
o
C. The efficiency of boiler is 75%and factor of
evaporation 1.15.Specific heat of superheated steam at constant pressure is 2.3.
Calculate:
(i) Degree of superheat and temperature of steam generated
(ii) Calorific value of coal in kJ/kg
(iii)Equivalent evaporation in kg of steam per kg of coal
d. In a Parson turbine running at 1500 r.p.m., the available enthalpy drop for an
expansion is 65 kJ/kg. If the mean diameter of the rotor is 100cm, find the number of
rows of moving blades. Assume stage efficiency = 80%, speed ratio = 0.7, and blade
outlet angle = 20
o
.
e. A turbo jet engine consumes air at the rate of 60.2 kg/sec when flying at a speed of
1000 km/hr Calculate, (a) the exit velocity of jet when the enthalpy change in the
nozzle is 230 kJ/kg and velocity coefficient is 0.96, (b) fuel flow rate in kg/sec when
air fuel ratio is 70:1, (c) thrust specific fuel consumption, (d) propulsive power, (e)
propulsive efficiency, and (f) the overall efficiency.
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| 14-May-2019 09:00:19 | 45.115.62.2
FirstRanker.com | 14-May-2019 09:00:19 | 45.115.62.2
RME403
Page 1 of 2
Printed Pages:02 Sub Code: RME403
Paper Id: 140268 Roll No.
B. TECH.
(SEM IV) THEORY EXAMINATION 2018-19
APPLIED THERMODYNAMICS
Time: 3 Hours Total Marks: 70
Note: Attempt all Sections. If require any missing data; then choose suitably.
SECTION A
1. Attempt all questions in brief. 2 x 7 = 14
a. What do you mean by air standard cycles? Discuss its? significance.
b. Define the following:
Brake power, Indicated power, Brake mean effective pressure, and Indicated mean
effective pressure.
c. Enlist the requirements of a good boiler?
d. What do you mean by supersaturated flow?
e. Give limitations of Carnot vapour power cycle and explain how Rankine cycle helps in
overcoming them.
f. Differentiate between impulse and reaction steam turbines.
g. Explain the significance of choked flow in a nozzle.
SECTION B
2. Attempt any three of the following: 7 x 3 = 21
a. Derive an expression for air standard efficiency of Otto cycle in terms of compression
ratio.
b. A steam engine working on Rankine cycle operates between 1.96 MPa, 250?C and
13.7 kPa. If engine consumes steam at the rate of 0.086 kg per second, determine
Rankine cycle efficiency, neglecting pump work. Also, find Rankine cycle efficiency
considering pump work..
c. A boiler generates 7.5 kg of steam per kg of coal burnt at a pressure of 11 bar from
feed water having a temperature of 70
o
C. The efficiency of boiler is 75%and factor of
evaporation 1.15.Specific heat of superheated steam at constant pressure is 2.3.
Calculate:
(i) Degree of superheat and temperature of steam generated
(ii) Calorific value of coal in kJ/kg
(iii)Equivalent evaporation in kg of steam per kg of coal
d. In a Parson turbine running at 1500 r.p.m., the available enthalpy drop for an
expansion is 65 kJ/kg. If the mean diameter of the rotor is 100cm, find the number of
rows of moving blades. Assume stage efficiency = 80%, speed ratio = 0.7, and blade
outlet angle = 20
o
.
e. A turbo jet engine consumes air at the rate of 60.2 kg/sec when flying at a speed of
1000 km/hr Calculate, (a) the exit velocity of jet when the enthalpy change in the
nozzle is 230 kJ/kg and velocity coefficient is 0.96, (b) fuel flow rate in kg/sec when
air fuel ratio is 70:1, (c) thrust specific fuel consumption, (d) propulsive power, (e)
propulsive efficiency, and (f) the overall efficiency.
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RME403
Page 2 of 2
SECTION C
3. Attempt any one part of the following: 7 x 1 = 7
(a) Explain Morse test in detail.
(b) Determine thermal efficiency and mean effective pressure of thermodynamic cycle
used by a 4-strokepetrol engine. Details of cycle are as follows.
Compression ratio = 7
Initial state = 100 kPa and 90?C
Swept volume = 0.1 m
3
Heat added to cycle at constant volume = 100 kJ/cycle.
Consider air as working fluid.
4. Attempt any one part of the following: 7 x 1 = 7
(a) Describe pass out turbines and back pressure turbines
(b) A binary vapour power cycle works on mercury and steam such that dry saturated
mercury vapour at4.5 bar is supplied to mercury turbine and leaves at 0.04 bar. Steam
is generated as dry saturated at 15 bar and supplied to steam turbine for being
expanded upto condenser pressure of 0.04 bar. Determine thermal efficiency of cycle.
For mercury take,
h
?
at 4.5 bar = 62.93 kJ/kg, h
g
at 4.5 bar = 355.98 kJ/kg,
v
f
at 0.04 bar = 0.0000765 m3/kg
h
?
at 0.04 bar = 29.98 kJ/kg, h
g
at 0.04 bar = 329.85 kJ/kg
s
g
at 4.5 bar = 0.5397 kJ/kg.K, sgat 0.04 bar = 0.6925 kJ/kg.K,
s
?
at 0.04 bar = 0.0808 kJ/kg.K
5. Attempt any one part of the following: 7 x 1 = 7
(a) Explain the working of water level indicator, safety valves, and fusible plug, feed
check valve, pressure gauge, stop valve and blow off cock.
(b) Discuss the causes of air leakage and its effect on condenser.
6. Attempt any one part of the following: 7 x 1 = 7
(a) A convergent divergent nozzle expands air at 6.89 bar and 427
0
C into a space at 1 bar.
The throat area is 650mm
2
and exit area is 975mm
2
. The exit velocity is found to be
680 m/s when the inlet velocity is negligible. Assuming negligible friction. Calculate
a) Mass flow through the nozzle.
b) Nozzle efficiency and coefficient of velocity.
(b) What do you understand by compounding of steam turbines? Describe different types
of compounding of steam turbines with appropriate diagram.
7. Attempt any one part of the following: 7 x 1 = 7
(a) A turbojet power plant uses aviation kerosene having calorific value of 43 MJ/kg. The
fuel consumption is 0.18 kg per hr per unit thrust, when thrust is 9 kN. The aircraft
velocity is 500 m/s the mass of air passing through the compressor is 27 kg/s.
Calculate the air fuel ratio and overall efficiency.
(b) Consider an ideal gas turbine cycle with two stages of compression and two stages of
expansion. The pressure ratio for each compressor and turbine is 3.The air enters each
stage of compressor at 300K and each stage of turbine at 1200K. Determine the back
work ratio and thermal efficiency of cycle assuming a) no regenerator b) regenerator
with 75% effectiveness.
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This post was last modified on 29 January 2020