变转速对旋翼悬停气动性能影响的试验与分析

为研究转速变化对旋翼悬停性能的影响,通过旋翼计算流体力学方法建模分析和缩比模型旋翼台试验的方法,以自研无铰式刚性旋翼为对象,研究了旋翼转速对悬停性能的影响规律。结果表明：基于运动嵌套网格和非定常流场求解建立的旋翼计算流体力学方法对悬停状态的气动性能计算精度较高,最大误差为6.84%；模型旋翼试验数据有效,具有良好的重复性；转速降低后相同总距对应的拉力系数更小,悬停效率拐点对应的拉力系数更大；拉力越小,变转速所节省的功率越明显,低拉力时可节省超过40%需用功率。可见改变转速可以显著提升悬停状态的旋翼气动性能。

Simulation and Test of Variable Speed Effect on Hovering Rotor Aerodynamic Performance

Aimed at investigating the variable speed effect on hovering rotor aerodynamic performance, a numerical method based on the computational fluid dynamics has been established, and the scaled rotor model test has been carried out. Relations between the hovering performance of a hingeless rigid rotor and the rotating speed was studied. The results show that the rotor computational fluid dynamics method based on the moving-embedded grid technique and unsteady flow field solving method has a high accuracy. The error of hovering performance calculation is no larger than 6.84%. The model rotor test data is valid and has good repeatability. When the rotating speed decreases, the lift coefficient corresponding to the same collective pitch is smaller, while the lift coefficient corresponding to the inflection point of the figure of merit is larger. The smaller the lift force, the more obvious the power saved by the variable speed. More than 40% of the power required can be saved for a low lift case. It is demonstrated that a significant improvement in hovering aerodynamic performance can be achieved by changing the rotating speed.