AU BE Aero AE6401 – AERODYNAMICS – 1 2015 Question Paper

Are you looking for Anna University 2015 April May old question papers? Here is a question paper from AU for BE Aeronautical Engineering. The subject is AE 6401 – AERODYNAMICS – 1. It's 04th Semester Examinations. Read more below.

Anna University Chennai

B.E/B.Tech. DEGREE EXAMINATION, APRIL/MAY 2015.

Fourth Semester

Aeronautical Engineering

AE 6401 – AERODYNAMICS – 1

(Regulation 2013)

Time: Three hours

Maximum: 100 marks

Answer all questions

                                     PART A – (10 × 2 = 20 marks)
1. Describe briefly when the use of an irrotational flow modal for incompressible aerodynamics applications is justified.
2. Explain briefly why induced drag of a finite wing is more than that of an infinite wing.
3. What is meant by Magnus effect?
4. State and explain Kutta condition.
5. State the continuity equation for compressible flow.
6. Why does lift and hence the circulation go to zero at the wing tips?
7. Why is turbulent boundary layer preferred for flow over spheres and cylinders?
8. Which kind of drag is predominant in the flow over bunt body and that over a stream lines body?
9. Usually, for an elliptical lift distribution over a wing must the chord vary elliptically long the span? Justify your answer with proper reasoning.
10. Write the Karman-Tsien rule for compressibility corrections.

                                  PART B- (5×16 = 80 marks)
11. (a) (1) If ∅ is defined as a scalar function of space coordinates and time, then show that curl grad ∅=0 certifies the flow field to be irrotational.
(2) What is the nature of streamlines forms ya uniform sources when placed all alone?
(3) A long elliptical cylinder with thickness to chord ratio of 1: 7 is placed with its major axis aligned with a uniform irrotational stream of 36 m/s. Calculate the perpendicular to each other?
Or
(b) (1) By considering the gradient of a scalar field show that the velocity potential lines and stream lines are perpendicular to each others?

(2) How we can synthesize the lifting flow over a circular cylinder?
Explain with the sketches how the stream line pattern and stagnation points changes for different values of circulation.

12, (a) Derive the equation of velocity field for non-lifting flow over a cylinder and obtain the location of stagnation points.
Or

(b) (1) Explain the physical meaning of divergence of velocity? Also write down the relation between line integrals, surface integrals, and volume integrals.

(2)Define and explain the circulation? Why the concept of circulation is very important in theoretical aerodynamics?

13.  (a) It is a well known result from the thin airfoils theory that, the coefficient of lift (C1) for a symmetrical airfoils kept in the potential flow at angle α is C1=2πα.Derive this result by transforming the lift flow over a circular into flow over a symmetrical airfoil using the Kutta – Joukowski transformation.
Or

(b) (1) Explain difference between point vortex, constant strength vortex panel and linearly varying strength vortex panel.

(2) A planer horse shoe vortex is placed symmetrically along OX on the x-axis with its BV aligned with the Y-axis. Determine a general expression for the down wash in the plane of symmetry.

14. (a) What is downwash? How does it affect the aerodynamics characteristic of a finite wing? Derive an expression for downwash using Prandtl’s lifting line theory?
Or
(b) Consider an airplane that weighs 10,700 N and cruises in level flight at 300 km/h at an altitude of 1000 m. The wing has a surface area of 17 square meters and an aspect ratio of 6.2.Assume that the lift co-efficient is linear function of the angle of attack and zero – lift angle of attack = -1.2.If the toad distribution is elliptic, calculate the value of the circulation at the centre of the wing, the downwash, induced drag coefficient? Take density value at this altitude as 0.90748.

15. (a) Prove Blasius theorem for incompressible flow a flat plate.

Or

(b) Consider the flow over a small flat which is 8 cm long in the flow direction and 1 m wide. The free stream conditions correspond to standard sea level, and the flow velocity is 120 m/s. Assuming laminar flow, calculate the boundary layer thickness at the downstream edge and the drag force on the plate. For the same flow over the same plate, assume that the boundary layer is now completely turbulent. Calculate the boundary layer is now completely turbulent Calculate the boundary layer thickness at the trailing edge and the drag force on the plate

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