Define aerodynamics and identify the applications of aerodynamics.
What are the sources of the aerodynamic drag? Name them.
Consider a Boeing 747 airliner cruising at a velocity of 246 m/s at a standard altitude of 11 km, where the freestream pressure and temperature are 22.7 kPa and 216.77 K, respectively. A one-fiftieth scale model of the 747 is tested in a wind tunnel where the temperature is 238.88 K. determine the required velocity and pressure of the test airstream in the wind tunnel such that the lift and drag coefficients measured for the wind-tunnel model are the same as for free flight. Assume that both μ\muμ and velocity of sound are proportional to T1/2T^{1/2}T1/2.
Explain the importance of aerodynamics citing at least two examples.
What are the different types of drag? Explain induced drag.
An aircraft flies at a Mach number of 0.850.850.85 at 18300 m18300 \text{ m}18300 m where the pressure is 7160 N/m27160 \text{ N/m}^27160 N/m2 and temperature is −56.5∘C-56.5^\circ\text{C}−56.5∘C. A model of 1/101/101/10-th scale is to be tested in a high speed wind-tunnel. Determine the total pressure of the tunnel stream necessary to give dynamic similarity, if the total temperature is 50∘C50^\circ\text{C}50∘C. It may be assumed that the dynamic viscosity is related to the temperature as follows: μμ0=(TT0)1.1\frac{\mu}{\mu_0} = \left(\frac{T}{T_0}\right)^{1.1}μ0μ=(T0T)1.1 where T0=273∘CT_0 = 273^\circ\text{C}T0=273∘C and μ0=1.71×10−5 kg/m⋅s\mu_0 = 1.71 \times 10^{-5} \text{ kg/m}\cdot\text{s}μ0=1.71×10−5 kg/m⋅s.
Define streamlined body. Differentiate between friction drag and pressure drag.
What are the sources of aerodynamic forces and moments that can be developed on aeronautical vehicles.
In low-speed, incompressible flow, the following experimental data were obtained for NACA4412 airfoil section at an angle of attack of 4∘4^\circ4∘: CL=0.85C_L = 0.85CL=0.85 and Cm,c/4=−0.09C_{m, c/4} = -0.09Cm,c/4=−0.09. Determine the location of center of pressure.