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Reg No.:_ Name:
APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
SEVENTH SEMESTER B.TECH DEGREE EXAMINATION(S), MAY 2019

Course Code: ME409
Course Name: COMPRESSIBLE FLUID FLOW

Max. Marks: 100 Duration: 3 Hours
Use of Gas Tables Permitted, Assume suitable value for missing data
PARTA
Answer any three full questions, each carries 10 marks. Marks

1 ஐ What is Mach angle? Derive an expression for Mach angle in terms of Mach (4)
number.

b) A perfect gas having Cp = 1017.4 J/kg and molecular weight 28.97 flows (6)
adiabatically in a converging passage with a mass flow rate if 29.18kg/s. At a
particular location, M = 0.6, T = 550K and p = 0.2 MPa. Calculate the area of
cross section of the duct at the location.

2 Derive the expression for sonic velocity in terms of the difference of specific (10)
heats and the ratio of specific heats of the medium.

3 Derive an expression for mass flux in terms of Mach number for an isentropic (10)
flow. From the expression for mass flux determine the condition for maximum
mass flux.

+ A supersonic nozzle expands air from po = 25 bar and To = 1050 K to an exit (10)
pressure of 4.35 bar; the exit area of the nozzle is 100 ണ്‌. Determine (a) throat
area (b) pressure and temperature at the throat (c) temperature at exit (d) exit
velocity as fraction of the maximum attainable velocity and (e) mass flow rate

PART 13
Answer any three full questions, each carries 10 marks.

5 9) What do you meant by shock strength? (3)
b) Explain why shock is impossible in subsonic flow. (3)
c) What is an expansion fan? How does it occur in supersonic flow? (4)
6 A convergent divergent nozzle has an exit to throat area ratio of 3.0. The (10)

stagnation properties of air at inlet are 700 KN/m? and 90 °C. The throat area is
10 ണ്‌. Due to its operation at off design condition a plane normal shock is seen
to stand at the section where M = 2. Determine the Mach number, static pressure

and static temperature at the exit of the nozzle. Assume isentropic flow before

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