Reg No.:_

G192108 Pages:2

Name:

APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY

SEVENTH SEMESTER B.TECH DEGREE EXAMINATION(R&S), DECEMBER 2019

Max. Marks: 100

(b)

b)
4
5 ஐ
b)
6

Course Code: ME409
Course Name: COMPRESSIBLE FLUID FLOW

Use of Gas Tables permitted. Assume suitable values for missing data.
PARTA
Answer any three full questions, each carries 10 marks.
Derive the conservation of mass equation for compressible flow through a
control volume.
Derive an expression for stagnation temperature in terms of Mach number for
compressible fluid flow.
A supersonic fighter plane flies at an altitude of 5000 m. The Mach number of
the fighter plane is 3.0. Estimate the time taken by an observer on the ground to
hear the sonic boom after the plane passes directly over his head. Take the
average temperature at 5000 m altitude as 10°C. Also determine the speed of
the aircraft.
Derive an expression for area ratio in terms of Mach number for isentropic
flow. Explain graphically the variation of area ratio with Mach number.
Derive the condition at which flow become choked in isentropic flow?
An air nozzle is to be designed for an exit Mach number of 2.5. Conditions of
the air available in the reservoir are 800 kPa, 523 K. Estimate i) pressure ii)
temperature iii) velocity of flow iv) area, at throat and exit of the nozzle. Mass
flow rate through the nozzle is 12000 kg/hr.
PART छ
Answer any three full questions, each carries 10 marks.
Define shock strength.
Derive an expression for Mach number downstream of a normal shock.
The ratio of exit to entry area in a subsonic diffuser is 3.5. The Mach number of
a jet of air approaching the diffuser is 2.18. Stagnation pressure of the jet is 1
bar and its static temperature is 300 K. There is a standing normal shock wave
just outside the diffuser entry. The flow in the diffuser is isentropic. Determine

pressure, temperature and Mach number at the exit of the diffuser. Also find the

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Duration: 3 Hours

Marks

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(6)

(6)

(4)
(10)

(2)
(8)
(10)