An Experimental Investigation of Compound Helicopter Aerodynamics in Level and Descending Forward Flight and in Ground Proximity.

摘要

A series of experiments was performed on the Princeton Dynamic Model Track on a compound helicopter model with an 8-foot-diameter hingeless rotor. Rotor,wing and fuselage forces and moments were measured as functions of advance ratio,rotor angle of attack,and collective pitch at various combinations of wing size and position,including wing off and wing and fuselage off. Test conditions included forward level flight,partial-power steep descent,and slow longitudinal and lateral flight in ground proximity. The results of these experiments are presented as functions of advance ratio in nondimensional coefficient form based on rotor tip speed and an appropriate characteristic area,such as rotor area or wing area. (Author)