1. Sketch the flow field around an airfoil that has stalled. Show the boundary layers, the separated region, and the wake.
2. Estimate the takeoff speed for an aircraft with conventional airfoils if the aircraft with payload weighs 120 000 N and the effective wing area is 20 m2 assuming a temperature of (a) 30-C, (b) 10-C, and (c) 220-C. An angle of attack at takeoff of 8o is desired.