Aerospace Engineering GATE 2019 Questions with Answer

Ques 1 Aerodynamics

For a NACA 2415 airfoil of chord length c, which of the following is true?

Ques 2 Aerodynamics

To simulate the aerodynamic forces on a cylinder of 1 m diameter due to a uniform air flow of 1 m/s at standard temperature and pressure (STP), low-speed wind tunnel experiments at STP are conducted on a 0.1 m diameter cylinder. The free stream air speed in the wind tunnel experiments should be _______ m/s (round off to the nearest integer).

Ques 3 Aerodynamics

The span-wise distribution of circulation over a finite wing of span b = 10 m is

Ques 4 Aerodynamics

Consider an airplane with a weight of 8000 N, wing area of 16 m^2, wing zero-lift drag coefficient of 0.02, Oswald's efficiency factor of 0.8, and wing aspect ratio of 6, in steady level flight with wing lift coefficient of 0.375. Considering the same flight speed and ambient density, the ratio of the induced drag coefficient during steady level flight to that during a 30° climb is _______ (round off to 2 decimal places).

Ques 5 Aircraft Performance

A propeller driven airplane has a gross take-off weight of 4905 N with a wing area of 6.84 m². Assume that the wings are operating at the maximum C_L^3/2/C_D of 13, the propeller efficiency is 0.9 and the specific fuel consumption of the engine is 0.76 kg/kW-hr. Given that the density of air at sea level is 1.225 kg/m³ and the acceleration due to gravity is 9.81 m/s², the weight of the fuel required for an endurance of 18 hours at sea level is _______ N (round off to the nearest integer).

Ques 6 Aircraft Propulsion

The propulsive efficiency of a ramjet engine is lower than that of a low bypass turbofan engine operating under the same conditions and producing the same thrust, primarily because the ramjet engine _______.

Ques 7 Aircraft Propulsion

While flying at Mach 2.0, 11 km altitude and producing the same thrust, what is the correct order from the lowest thrust specific fuel consumption (tsfc) to the highest tsfc?

Ques 8 Aircraft Propulsion

For a single stage subsonic compressor, which of the following statements about the highest possible compressor pressure ratio (CPR) is correct?

Ques 9 Aircraft Propulsion

For a rocket engine, the velocity ratio r is V_a/V_e, where V_a is the vehicle velocity and V_e is the exit velocity of the exhaust gases. Assume the flow to be optimally expanded through the nozzle. For r = 2, if F is the thrust produced and ṁ is the mass flow rate of exhaust gases, then, F/(ṁV_e) is _______.

Ques 10 Aircraft Propulsion

The specific impulse of a rocket engine is 3000 Ns/kg. The mass of the rocket at burnout is 1000 kg. The propellant consumed in the process is 720 kg. Assume all factors contributing to velocity loss to be negligible. The change in vehicle velocity Δu is _______ km/s (round off to 2 decimal places).

Ques 11 Aircraft Propulsion

The combustion products of a gas turbine engine can be assumed to be a calorically perfect gas with γ = 1.2. The pressure ratio across the turbine stage is 0.14. The measured turbine inlet and exit stagnation temperatures are 1200 K and 900 K, respectively. The total-to-total turbine efficiency is _______ % (round off to the nearest integer).

Ques 12 Aircraft Propulsion

The figure shows the velocity triangles for an axial compressor stage. The specific work input to the compressor stage is _______ kJ/kg (round off to 2 decimal places).

Ques 13 Calculus

The maximum value of the function f(x) = xe^-x (where x is real) is _______.