B.TECH - Semester 7 gas dynamics Question Paper 2019 (jun)
Practice authentic previous year university questions for better exam preparation.
Sample Questions
- Sketch on T-S plane isentropic and actual expansion of compressible fluid and give the expression for nozzle efficiency.
- Deduce the expression for impulse function.
- Explain the difference between flow and non flow work.
- What is the effect of Mach number on compressibility?
- Sketch the Fanno line as $h-s$ and $h-p$ diagrams and explain how these lines are constructed.
- Distinguish between Rayleigh flow and Fanno flow.
- How do the flow properties change in Rayleigh flow?
- Under what condition a compression wave changes into a shock wave.
- State two practical situations where oblique shock waves are produced.
- Write the change across normal shock for Mach number and Static pressure. $$ (10 \times 4=40 \text { Marks }) $$ P.T.O. PART - B
- (a) Carbon-dioxide expands isentropically through a nozzle from a pressure of 3.2 bar to 1.0 bar. If the initial temperature is $475^{\circ} \mathrm{K}$ determine the final temperature, the enthalpy drop and the change in internal energy.
- (b) A conical air diffuser has an intake area of $0.11 \mathrm{~m}^{2}$ and an exit area of 0.44 $\mathrm{m}^{2}$. Air enters the diffuser with a static pressure of 0.18 MPa , static temperature of $37^{\circ} \mathrm{C}$ and velocity of 267 mis . Ca...
- (i) the mass flow rate of air through the diffuser, (ii) the Mach number, static temperature and static pressure of the air leaving diffuser and (iii) the net thrust acting upon the diffuser due to diffusion.
- (a) Derive the expression for the area expansion ratio of nozzles.
- (b) A Freon-turbine has to use a maximum flow rate of $5 \mathrm{~kg} / \mathrm{s}$ of Freon employing a ring of convergent nozzles of total exit area of cross-section of $100 \mathrm{~cm}^{2}$. The pressure in the nozzle entry space is $20 \times 10...
- Air is flowing into an insulated duct with a velocity of $150 \mathrm{~m} / \mathrm{s}$. The temperature and pressure at the inlet are $280^{\circ} \mathrm{C}$ and 28 bar respectively. Find the temperature at a section in the duct where the pressure ...
- Air flows through a constant area duct with inlet temperature of $20^{\circ} \mathrm{C}$ and inlet Mach number of 0.5 . What is the possible exit stagnation temperature? it is desired to transfer heat such that at exit of the duct the stagnation temp...
- A convergent divergent nozzle is designed to expand air from a reservoir in which the pressure is 700 kPa and temperature is $5^{\circ} \mathrm{C}$ and the nozzle inlet Mach number is 0.2 . The nozzle throat area is $46 \mathrm{~cm}^{2}$ and the exit...
- (a) Deduce the Hugoniot equation for shock heating and explain the same on $p-v$ plane. Also give the advantage of shock heating.
- (b) Explain why normal shock wave causes supersonic flow to jump to subsonic flow. Substantiate your answer with governing equations, relevant reasons and using T-s diagram. $$ \text { ( } 3 \times 20=60 \text { Marks) } $$