AN INVESTIGATION OF A WING-PROPELLER CONFIGURATION EMPLOYING LARGE-CHORD PLAIN FLAPS AND LARGE-DIAMETER PROPELLERS FOR LOW-SPEED FLIGHT AND VERTICAL TAKE-OFF

摘要

An investigation of the effectiveness of a wing equipped with large-chord plain flaps and auxiliary vanes In rotating the thrust vector of two large-diameter propellers through the large angles required for ver¬tical take-off and low-speed flight has been conducted in the Langley 300 MPH 7- by 10-foot tunnel. The semispan model used was equipped with a 60-percent-chord flap, a JO-percent-chord flap, and two large-diameter overlapping propellers.nUnder static-thrust conditions, a maximum upward rotation or the effective thrust vector of 450 was obtained with the 60-percent-chord flap deflected 30° and the JO-percent-chord flap deflected 50°. With the addition of two auxiliary vanes, the upward deflection of the thrust vector was increased to 670. With this configuration, vertical take-off could be made with a take-off attitude of 23° and at airplane weights up to 95 percent of the thrust. A method is presented for calculating the lift due to flap deflection and slipstream for small flap deflections if the lift due to flap deflection at zero thrust and the lift due to flap deflection at zero forward speed are known.