INVESTIGATION OF THE EFFECTIVENESS OF BOUNDARY-LAYER CONTROL BY BLOWING OVER A COMBINATION OF SLIDING AND PLAIN FLAPS IN DEFLECTING A PROPELLER SLIPSTREAM DOWNWARD FOR VERTICAL TAKE-OFF

摘要

An investigation of the effectiveness of blowing a jet of air over the flaps of a wing equipped with a 50-percent-chord sliding flap and a 25-percent-chord plain flap in deflecting a propeller slipstream down¬ward for vertical take-off has "been conducted in a static-thrust facility at the Langley Aeronautical Laboratory. The effects of a leading-edge slat, ground proximity, end plate, and propeller position were also investigated.nThe results of the investigation indicated that boundary-layer control is an effective means of maintaining attached flow to flap deflections higher than those which could otherwise be used to provide increases in resultant force and turning angles.