Investigation of the Aerodynamic Characteristics of a Model Wing-propeller Combination and of the Wing and Propeller Separately at Angles of Attack Up to 90°

Résumé du livre

Predicted characteristics of an assumed airplane designed for vertical take-off indicate that partial wing stalling would be encountered at certain attitudes even though sufficient power was available for flight at any attitude. The effects of slipstream on the variation of lift-curve slope with thrust coefficient for this model could be satisfactorily estimated by means of a modified form of a method formulated by Smelt and Davies. The variation of propeller normal florce with angle of attack compared favorably with calculated values. An appreciable direct pitching moment was found to exist on the propeller itself at high angles of attack. This pitching moment was approximately doubled when the propeller was operated in the presence of the wing and corresponded to a downward movement of the effective center of thrust of about 20 percent of the propeller radius.