MET443 Aerospace Engineering Question Bank PDF

Question Bank MET443 AEROSPACE ENGINEERING (Elective) Syllabus Module 1 The atmosphere - characteristics of troposphere, stratosphere, thermosphere, and ionosphere- pressure, temperature and density variations in the atmosphere. Application of dimensional analysis...

Question Bank MET443 AEROSPACE ENGINEERING (Elective) Syllabus Module 1 The atmosphere - characteristics of troposphere, stratosphere, thermosphere, and ionosphere- pressure, temperature and density variations in the atmosphere. Application of dimensional analysis – aerodynamic force – model study and similitude. 2D aero foils -Nomenclature and classification- pressure distribution in inviscid and real flows- momentum and circulation theory of aero foil- characteristics. Module 2 3D or finite aero foils - effect of releasing the wingtips- wing tip vortices - replacement of finite wing by horse shoe vertex system, lifting line theory-wing load distribution - aspect ratio, induced drag calculation of induced drag from momentum considerations. Skin friction and from drag- changes in finite wing plan shape ……………………………………………………………………………………………………………………………………………………………. 1. Classify different regions of standard atmosphere based on the temperature variation. 2. Explain why the temperature varies in different regions of atmosphere. 3. Calculate the temperature, pressure and density of standard atmosphere at 6km, 11km and 18km altitudes. 4. Explain the different types of drag encountered by aeroplanes. 5. Derive the general equations of motion of an aircraft. 6. With help of a schematic explain the variation of forces acting on an aircraft during take-off. 7. what is the difference between force vortex and free vortex? 8. Explain Kutta condition. 9. Derive continuity Equation. 10 Define Kutta-Joukowskis theorem. 11.Derive Navier stokes equation. 12.Define Blasius solution. 13.Explain Airfoil and wing theory. 14.Derive the expressions for the pressure and density distributions in isothermal regions of atmosphere. 15. Explain geometric, kinematic and dynamic study in model studies. 16. If an airplane is flying at an altitude where the actual pressure and temperature are 0.5 bar and 159.5 K respectively, what are the pressure, temperature and density altitudes? 17.Draw the pressure distribution around a 2D airfoil. 18.Explain geopotential and geometric altitudes. 19.What is meant by aerodynamic centre? 20.Why coefficent of pressure is used for plotting the pressure distribution in an airfoil? 21.Explain how the variation of pressure and density at different altitudes can be calculated. 22.Consider an airplane flying at an altitude where the pressure and temperature are 25.37 Kpa and 216.66 K, respectively. Calculate the pressure and density altitudes at which the airplane is flying. 23.Explain why temperature varies in different regions of atmosphere. 24.If an airplane flying at an altitude where the pressure and temperature are 0.472 x 105 N/m2 and 255.7 K, respectively, what are the pressure, temperature and density altitudes? 25.Write a summary of the different drags that are acting on a 3D airfoil. 26.How induced drag is developed. Explain. 27.What do you mean by high lift devices? With sketches, compare the maximum lift produced by different high lift arrangements with that of a plane airfoil. 28.Briefly explain the developments of Aerospace Engineering in Indian space missions. 29.Discuss Skin friction and Skin friction drag. 30.Write a brief note on standard atmosphere. 31.With the help of a diagram explain the variations of temperature in different regions of atmosphere. 32.Calculate the pressure, temperature and density of standard atmosphere at 9 km and 15 km. 33.Explain the term pressure coefficient. Plot the variation of the pressure coefficient around an airfoil. 34.Explain how lift coefficient can be obtained from pressure coefficient. 35.An aircraft having wing span 9.6 m and wing area 17m2 produces a lift of 80000 N when flying at 120 m/s. Calculate the induced drag when flying at sea level, Assume e=0.8. 36.Write some methods to reduce wing tip vortices. 37.Explain the terms down wash and induced drag. 38.What are wing tip vortices? Why are they generated? What is the purpose of having a winglet? 39.Explain based on velocity profiles, why the laminar boundary layer is expected to separate more easily than the turbulent boundary layer. 40. Show zones of laminar, transitional and turbulent flow on an airfoil placed in a laminar free stream. What will happen if there is turbulence in the freestream? 41.What are the various components of drag experienced by a finite wing at subsonic speeds? 42.What is an inviscid flow? Under what conditions can a flow be considered inviscid? 43.What are the different components of drag that an airfoil experiences in an incompressible flow? 44.State the Bernoulli’s equation and explain it mentioning the assumptions. 45.Explain what is meant by circulation. Relate circulation along a closed curve in a fluid to the vorticity of the fluid inside the curve. 46. Explain why the concept of horseshoe vortex is used for finite wing. 47.What are the difficulties of using a single horseshoe vortex for finite wing? 48.What are aircraft trailing vortices? How are they formed? What difficulties are faced by busy airports because of these trailing vortices? 49. How does the airfoil chord line differ from the camber line? 50. What do the elevators of an aircraft do? 51.What are aerodynamic centre and centre of pressure of an airfoil? Which of them changes with angle of attack? 52.Starting from Navier Stokes Equations for incompressible constant density flow, derive the steady Euler equations stating the assumptions made. 53. Define the following terms: (i) airfoil chord (ii) airfoil angle of attack (iii) wing planform (iv) geometric and aerodynamic mean chord of a wing (v) wing spars and ribs (vi) wash-in and wash- out. 54. Explain air-foil nomenclature with a neat sketch. 55. Explain the classification of 2D aero foils. 56. State the Buckingham pi theorem. 57.Using the Buckingham pi theorem, show that the non-dimensional aerodynamic moments are functions of free stream Mach number and Reynolds number. 58.What is Kutta condition? State and explain its significance in the solution of inviscid and incompressible flow. 59.Explain the importance of dimensionless analysis. 60.What do you mean by similarity of flow? 61.Explain how turbulence is associated with vorticity. 62.Define total temperature and total pressure. 63.Derive Navier-Stokes equations. 64.Derive Bernoulli’s equation. 65.Explain the structure of atmosphere with characteristics of each layer. 66.Explain the reasons for varying pressure with altitude. 67. Explain the four forces controlling a moving flight? 68.Write some methods to reduce the wing tip vortices. 69.The pressure drop P along a straight pipe of diameter D has been experimentally studied and it is observed that for a laminar flow of a given fluid and pipe, the pressure drop varies directly with the distance, , between pressure taps. Assume that P is a function of D and , the velocity V and the fluid viscosity . Use dimensional analysis to deduce how the pressure drop varies with pipe diameter. 70.What do you mean by temperature, pressure and density altitudes? 71.What is meant by static and dynamic stability of an aircraft. 72.Explain the lifting line theory. 73.Explain Kevin’s circulation theorem. 74. What are the aerodynamic characteristics of airfoil? 75.What are the applications of airfoil? 76.Explain Prandl’s lifting line theory. 77.Explain how the prandl’s lifting line theory can be used to calculate the aerodynamic characteristics of a finite wing. 78.Explain span efficiency factor. 79.What is meant by aerodynamic center? 80.Derive the expression for induced drag. 81.Write a summary of different drags that are acting on a 3D aerofoil. 82.With sketches compare the maximum lift produced by different high lift arrangements with that of a plane aerofoil. 83. Write energy equation for 2D steady incompressible flow and explain the significance of each term involved in the equation. 84. Write Bernoulli’s equation for 2D steady incompressible flow and explain the significance of each term involved in the equation. 85.Write Euler’s equation for 2D steady incompressible flow and explain the significance of each term involved in the equation. 86.Write Navier Stoke’s equation for a 3D steady incompressible flow and explain the significance of each term involved in the equation. 87.Explain the significance of Prandtl’s lifting-line equation. 88.Deduce the Euler’s equation from momentum equations. 89.Derive the momentum equation for viscous incompressible flow. 90. Write the Prandtl’s lifting-line theory and explain its use. 91.Why coefficient of pressure is used for plotting the pressure distribution in an airfoil? 92.Compare airfoil theory and lifting line theory. 93.Give the limitations of lifting line theory. 94.Explain vortex line and horse shoe vortex? 94. Schematically represent and explain the pressure distribution in inviscid and real flows.. 95.What is Hard Space? 96.Which are the most important dimensionless numbers associated with aerospace engineering? 97.A ship 300m long moves in sea water, whose density is 1030 kg/m 3. A 1:100 model of this ship is to be tested in a wind tunnel. The velocity of air in the wind tunnel around the model is 30m/s and the resistance of the model is 60N. Determine the velocity of ship in sea water and also the resistance of ship in sea water. The density of air is given as 1.24kg/m3. Take the kinematic viscosity of sea water and air as 0.012 stokes and 0.018 stokes respectively. 98.The resisting force R of a supersonic plane during flight can be considered as dependent upon the length of the aircraft l, velocity V, air viscosity μ, air density ρ, and bulk modulus of air k. Express the functional relationship between the variables and the resisting force. 99.Which are the different types of forces encountered in fluid phenomenon? 100. A pipe of diameter 1.5m is required to transport an oil of specific gravity 0.9 and viscosity 3x10-2 poise at the rate of 3000litre/sec. Tests were conducted on a 15 cm diameter pipe using water at 20oC. Find the velocity and rate of flow in the model. 101. Define the following of an aircraft (i) aspect ratio (ii) planform. --oo0oo--