Question

b. A very thin wing section is being tested in a low speed wind-tunnel. Assuming that the flow on the surface of the wing produce a laminar boundary layer and the velocity profile is given as follows; Determine the theoretical value of; 8" where Rex is the Reynold number at a distance x from the leading edge of the wing, Rei is the Reynolds number at the trailing edge of the wing and Cr (or Cp) is the average skin fiction drag coefficient. CO2-14 marks) c. The wind is blowing at 10 m/s parallel to a very thin sign board measuring 10 m long and 5 m width. Calculate the total drag force on both side of the sign board. Given that kinematic viscosity v 1.42 x 10 5 m2/s, and air density p 1.247 kg/m3. Assumed laminar boundary layer profile as in Q1(b).

Answer 1