摘要
The performance of slowed-rotor compound aircraft,particularly at high-speed flight condition,is examined.The forward flight performance calculation model of the composite helicopter is established,and the appropriate wing and propeller parameters are determined.The predicted performance of isolated propeller,wing and rotor combination is examined.Three kinds of tip speed and a range of load share setting are investigated.Propeller bearing 80%of the thrust with wing sharing lift is found to be the best condition to have better performance and the maximum L/D for maximum forward speed.Detailed rotor,propeller,and wing performance are examined for sea level,1000 m,and 2000 m cruise altitude.Rotor,propeller,and wing power are found to be largely from profile drag,except at low speed where the wing is near stall.Increased elevation offloads lift from the rotor to the wing,dropping the total power required and increasing the maximum speed limit over 400 km/h.
研究了降转速复合式飞行器在高速飞行条件下的旋翼性能。建立了复合式直升机前飞性能的计算模型,确定了合适的机翼和螺旋桨参数。对螺旋桨、机翼和旋翼不同组合时的性能进行了预测。研究了3种不同的叶尖速度和载荷分布。结果表明,螺旋桨提供80%的推力并由机翼分担升力,以最大速度前飞时具有较好的性能和最大的升阻比。计算了在海平面、1000 m和2000 m高度巡航时旋翼、螺旋桨和机翼的性能。除了在低速飞行状态机翼接近失速时,旋翼、螺旋桨和机翼的功耗主要来自型阻。飞行高度的增加使旋翼的升力转移到机翼上,降低了总的需用功率,并使最大飞行速度超过了400 km/h。
