Download GTU (Gujarat Technological University) BE/BTech (Bachelor of Engineering / Bachelor of Technology) 2018 Winter 7th Sem New 2171914 Gas Dynamics Previous Question Paper
1
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ?VII (NEW) EXAMINATION ? WINTER 2018
Subject Code: 2171914 Date: 15/11/2018
Subject Name: Gas Dynamics
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
4. Use of gas tables and steam tables is permitted.
MARKS
Q.1 (a) Define the following terms: (a) Stagnation temperature (c) Stagnation
velocity of sound (c) Mach number.
03
(b) Explain Mach number and its significance.
04
(c) Define Gas dynamics state various laws applied in the study of gas
dynamics.
07
Q.2 (a) State assumptions made in deriving equations for Fanno flow. State two
engineering fluid flow conditions which can be analyzed as Fanno flow
03
(b) Show Rayleigh heating and Rayleigh cooling process on h-s diagram. 04
(c) Write a short on reference velocities. 07
OR
(c) Air enters the combustion chamber at 60kPa, 350K and 75m/s. the gasses
leave the combustion chamber at a mach number of 0.75. for a mass flow
rate of air of 30kg/s. Find mach number and stagnation temperature at
inlet, the exit stagnation temperature, the rate of heat transfer and rate of
fuel burnet of C.V. of 44 MJ/kg.
07
Q.3 (a) Discuss concept of formation of normal shock waves. 03
(b) State the assumptions in the analysis of Rayleigh flow and give
applications of Rayleigh flow.
04
(c) Discuss the following terms with help of sketch (a) Mach angle (b) Zone
of Silence (c) zone of action (d) Mach cone.
07
OR
Q.3 (a) Explain (a) stagnation pressure (b) stagnation temperature 03
(b) Define fanno flow process and state its governing equations. 04
(c) Derive the expression for the pressure ratio across normal shock in terms
of density ratio
07
Q.4 (a) What is strength of shock wave? Explain. 03
(b) Derive following form of Prandtl-mayer equation V1V2 = a
*2
04
(c) State and explain the practical application of wind tunnel 07
OR
Q.4 (a) Define critical state? Calculate the ratio of stagnation density to critical
density for mono-atomic ideal gas
03
(b) What are various types of wind tunnels used for low and high speed
testing of models?
04
(c) Draw the Fanno curve on h-s diagram and discuss the effect of friction in
case of subsonic and supersonic flow. What is the limiting value of Mach
number?
07
Q.5 (a) Define coefficient of compressibility and bulk modulus. 03
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1
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ?VII (NEW) EXAMINATION ? WINTER 2018
Subject Code: 2171914 Date: 15/11/2018
Subject Name: Gas Dynamics
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
4. Use of gas tables and steam tables is permitted.
MARKS
Q.1 (a) Define the following terms: (a) Stagnation temperature (c) Stagnation
velocity of sound (c) Mach number.
03
(b) Explain Mach number and its significance.
04
(c) Define Gas dynamics state various laws applied in the study of gas
dynamics.
07
Q.2 (a) State assumptions made in deriving equations for Fanno flow. State two
engineering fluid flow conditions which can be analyzed as Fanno flow
03
(b) Show Rayleigh heating and Rayleigh cooling process on h-s diagram. 04
(c) Write a short on reference velocities. 07
OR
(c) Air enters the combustion chamber at 60kPa, 350K and 75m/s. the gasses
leave the combustion chamber at a mach number of 0.75. for a mass flow
rate of air of 30kg/s. Find mach number and stagnation temperature at
inlet, the exit stagnation temperature, the rate of heat transfer and rate of
fuel burnet of C.V. of 44 MJ/kg.
07
Q.3 (a) Discuss concept of formation of normal shock waves. 03
(b) State the assumptions in the analysis of Rayleigh flow and give
applications of Rayleigh flow.
04
(c) Discuss the following terms with help of sketch (a) Mach angle (b) Zone
of Silence (c) zone of action (d) Mach cone.
07
OR
Q.3 (a) Explain (a) stagnation pressure (b) stagnation temperature 03
(b) Define fanno flow process and state its governing equations. 04
(c) Derive the expression for the pressure ratio across normal shock in terms
of density ratio
07
Q.4 (a) What is strength of shock wave? Explain. 03
(b) Derive following form of Prandtl-mayer equation V1V2 = a
*2
04
(c) State and explain the practical application of wind tunnel 07
OR
Q.4 (a) Define critical state? Calculate the ratio of stagnation density to critical
density for mono-atomic ideal gas
03
(b) What are various types of wind tunnels used for low and high speed
testing of models?
04
(c) Draw the Fanno curve on h-s diagram and discuss the effect of friction in
case of subsonic and supersonic flow. What is the limiting value of Mach
number?
07
Q.5 (a) Define coefficient of compressibility and bulk modulus. 03
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2
(b) How the enthalpy changes in the Rayleigh flow when heat addition
continues beyond maximum enthalpy point?
04
(c) A circular duct passes 8.25 kg/s of air at an exit Mach number of 0.5. The
entry pressure and temperature are 3.5bar and 38?C respectively and
coefficient of friction is 0.005. if the Mach number at entry is 0.15,
determine: (1) diameter of duct (2) length of duct (3) pressure and
temperature at exit.
07
OR
Q.5 (a) Derive expression for pressure ratio, temperature ratio and velocity ratio
for the Fanno flow of a perfect gas.
03
(b) Explain the phenomenon of choking in isentropic flow. 04
(c) A Mach -2 aircraft engine employs a subsonic inlet diffuser of area ratio
3. A normal shock is formed just upstream of the diffuser inlet. The free
stream conditions upstream of the diffuser are: p= 0.10 bar, T= 300 K.
Determine (a) Mach number, pressure and temperature at the diffuser
exit. (b) Diffuser efficiency including the shock. Assume isentropic flow
in the diffuser downstream of the shock.
07
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This post was last modified on 20 February 2020