Consider an naca 2412 airfoil in a low-speed fl ow at zero degrees angle of attack and a reynolds number of 8.9 × 10 6 . calculate the percentage of drag from pressure drag due to fl ow separation (form drag). assume a fully turbulent boundary layer over the airfoil. assume that the airfoil is thin enough that the skin-friction drag can be estimated by the fl at-plate results discussed in ch. 4.

Liquid flows at steady state at a rate of 2 lb/'s through a pump, which operates to raise the elevation of the liquid 100 ft from control volume inlet to exit. the liquid specific enthalpy at the inlet is 40.09 btu/lb and at the exit is 40.94 btub. the pump requires 3 btu/s of power to operate. if kinetic energy effects are negligible and gravitational acceleration is 32.174 tt/s, the heat transfer rate associated with this steady state process is most closely 1)-2,02 btu/s from the liquid to the surroundings 2)-3.98 btu/s from the surroundings to the liquid. 3)-4.96 btu/s from the surroundings to the liquid. 4)-1.04 btu/s from the liquid to the surroundings.