为研究桨叶沿展向不同位置的负扭转对直升机旋翼性能的影响，以各向异性复合材料中等变形梁模型为基础建立旋翼性能计算模型，实现在不同速度前飞时直升机旋翼需用功率的预测。理论预测与试飞数据对比一致，验证了本文分析模型的有效性。以UH-60直升机为样例，按翼型将桨叶沿展向分为内、中、外3段，从迎角和升阻比分布入手研究各段负扭对旋翼需用功率的影响效果和机理。整体上，直升机前飞速度越高，桨叶负扭的影响越明显。其中，内段负扭对旋翼性能有负面影响，但影响较小；中段负扭对桨盘上气流环境的改善起决定性作用，高速前飞时可使旋翼需用功率降低10%以上；外段负扭有利于降低需用功率，作用效果一般。通过遍历法得到了一组分段线性桨叶扭转方案，在各飞行状态时都优于线性负扭方案。
To investigate the effect of the blade twist on helicopter rotor performance, a rotor performance calculation model, based on anisotropic composite medium deformation beam model, is derived to predict the power required of a helicopter rotor at any flight speed. The theoretical prediction is consistent with the flight test data, which verifies the effectiveness of the analysis model. According to airfoil distribution of the UH-60 helicopter, the blade is divided into three segments, which are inner, middle and outer segment respectively. And the effect and its mechanism of the three segments on the required power are studied based on the distribution of angle of attack and the lift-drag ratio over the rotor disk. Overall, the faster the helicopter flies forward, the greater the effect of blade twist is. The twist of the inner segment has a negative effect on the rotor performance, but the effect is small. The twist of the middle segment plays a decisive role in improving the airflow environment over the rotor disk, and can reduce the required power by more than 10% in high-speed forward flight. The outer segment is beneficial to power reduction, and the effect is average. A set of piecewise linear twist schemes for each flight velocity are obtained by traversal method, which is better than linear twist scheme in any flight state.
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