Anna University Chennai B.E Aeronautical Engineering, AERODYNAMICS-II Question paper Part A-(10*2=20 marks) 1. Write the one dimensional energy flow for isentropic flow. 2. Describe the shape of the nozzle required to increase the velocity from subsonic to supersonic condition. 3. Differentiate between normal shock wave and oblique shock wave. 4. What is meant by Fanno Flow? 5. Differentiate between Mach wave and Shock wave. 6. What is perturbation potential? 7. Define drag divergence Mach number. 8. Name and sketch various supersonic files. 9. What is meant by transonic wind tunnel? 10. What are the advantages of optical methods of flow visualization?
Part B-(5*16=80 marks) 11.Derive the three dimensional continuity equation for a compressible flow. State the assumptions made. or 12. With a neat sketch explain the variation of static pressure of flow in a Convergent-Divergent nozzle under various back pressures. 13.Explain how a subsonic nozzle can be supersonic diffuser. [4 marks] An aircraft flying at a Mach number 1.3 at an altitude 16000 m (p=0.15 bar, T = 216 K). The compression in its engine is partly achieved by a normal shock wave
standing at the entry of its diffuser. Determine immediately downstream of the shock. (a) Mach number (b) Temperature of the air (c) Pressure of the air (d) Change in entropy across the shock wave [12 marks] Or 14. A combustion chamber in a gas turbine plant recieves air at 350 K, 0.55 bar and 75 m/s. The air-fuel ratio is 30 and the calorific value of the fuel is 42 MJ/Kg. Taking lambda = 1.4 and R = 287 J/Kg K for the gas determine: (a) The initial and final Mach numbers. (b) Final pressure, temperature and velocity of the gas. (c) Percent stagnation pressure loss in the combustion chamber and (d) the maximum stagnation temperature attainable. 15. Derive the linearized velocity potential equation for compressible flow and based on the equation derived the Prandtl-Glauert rule. Or 16. (a) Derive expressions for the lift and drag coefficients of a diamond aerofoil using linear theory. [8 marks] (b) A flat plate size 1 m * 0.5 is tested at 1500 Kmph at the freestream pressure pressure of 0.8 MPa and temperature 30° C at an angle of attack of 5 degree. Using linear theory estimate the lift and drag. [8 marks] 17. (a) Explain upper and lower critical Mach numbers. [8 marks] (b) Briefly discuss area rule and supercritical airfoil. [8 marks]
Or 18. What is the role of sweep back and sweep forward for aircraft wings? Explain the aerodynamic characteristics of swept wings. 19. Explain the working principle of shock tube with necessary sketches on pressure variation in the tube. What are the advantages and limitations on the operations of a shock tube? Or 20. (a) with a neat sketch explain the working principle of a supersonic wind tunnel. [8 marks] (b) with aid of sketch explain the optical method of interferometer. [8 marks]
