大前进比变转速旋翼气弹动力学建模与载荷特性分析

Aeroelastic modeling and load analysis of a variable speed rotor in high advance ratio

针对大前进比变转速旋翼气弹动力学问题开展分析研究。基于Hamilton原理以及中等变形梁理论建立旋翼动力学方程,并针对大反流区气动力计算方法和大前进旋翼气弹配平计算方法进行修正,集成考虑大前进比的旋翼气弹计算模型。在旋翼动力学模型的验证基础上,开展大前进比下变转速旋翼气弹动力学计算分析。通过计算桨叶剖面气动和结构载荷表明:随着前进比增加,反流区内桨叶剖面出现周期交变的脉冲式法向力和气动力矩;桨叶挥舞、摆振弯矩随转速降低而增加,且在接近共振转速频率时挥舞和摆振弯矩明显增加。提取桨叶结构载荷中的气动部分,表明脉冲气动力会带来显著的气动部分变化。

The rotor dynamics issue of a variable speed rotor in high advance ratio was analyzed.The rotor dynamics model was built with the Hamilton principle and the middle deformation beam theory,and the aerodynamic force computing method in reverse region and the rotor trim method were corrected.Finally the rotor aeroelastic analysis model was built and the calculation in high advance ratio was contained.The rotor dynamic model was validated.By calculating the aero loads and structure loads,it was indicated that the air force would be periodically alternate and pulsed.The flap bending moment and edge bending moment increased with reducing rotor speed and would be greatly increased in resonant rotor speed region.It was validated that the periodically alternate and pulsed air force would increase the contribution of air force in structure loads.