Theodorsen's Propeller Performance with Rollup and Swirl in the Slipstream

摘要

THEODORSEN'S classic theory,~1, elegant and efficient as it is for the design of optimal propellers under specified conditions, suffers from an unrealistic high average static pressure in the slip- stream. This high pressure has its impact on the expressions for predicted thrust, power, and efficiency. In earlier papers~2,3 this au- thor has pointed out that the high pressure is inherent to the model with rigid vortex sheets in the slipstream. It is unrealistic to maintain the rigidity down to the Trefftz plane. The high pressure is eased by allowing rollup of the vortex sheets.