1. A propeller 2 f t in diameter moves at 20 f t/s in water and produces a thrust of 1000 lbf . Find the ratio of the upstream to downstream velocities, and the efficiency.
2. An airplane flies at 140 mph at sea level at 60?F. The propeller diameter is 8 f t, and the slipstream has a velocity of 200 mph relative to the airplane. Find:
(a) The propeller efficiency.
(b) The flow velocity in the plane of the propeller.
(c) The power input.
(d) The thrust of the propeller.
(e) The pressure difference across the propeller disk.