Question

A Piper Cherokee is flying at 4000 ft standard altitude at 105 mph. The wing has a rectangular planform (shape) with a span of 30 ft and a chord of 5.33 ft. Assuming that the turbulent boundary layer grows as on a smooth plate and a completely turbulent boundary layer flow, determine: (a) The boundary layer thickness at the downstream edge of the wing. (b) The total skin friction drag coefficient of the wing. (c) The total skin friction drag of the wing in pounds

Answer 1

A Piper Cherokee is flying at standard altitude. The wing has a rectangular planform (shape) with a span of Assuming that the turbulent boundary layer grows as on a smooth plate and a completely turbulent boundary layer flow. F = 89.485/0.81 = 9.18 kg F = 9.123 times 8.20462 F_0 = 80.109 For domain flow: Assuming upper number Re < 3 times 10^5 From 'B' equation delta = 5x/squareroot Re = 5 times 5.33 times 0.3048/(3 times 10^5)^6.5 delta = 0.01484 m \r\n C_p = 1.326/squareroot R_C_2 = 1.325/squareroot 3 times 10^5 [Because From eq] F_D = C_D times 1/2 integral A V^2_infinity = 242 times 10^-3 times 1/2 times 30 times 9.33 times (0.3098)^12 times (96.929) F_D = 40.44 N F_D = 9.0879 Velocity = 105 mPh 1 mile = 1.609 km. Velocity = 105 times 1.609 = 168.945 times 1000/3600 Velocity = 46.929 m/s \r\n P = P_0 e^-2 g/RT P = 101325.e^-1219.2 times 9.81/0.287 times 300 P = 88.1835 kPa For Assume: * Aie is a fluid.