后缘小翼智能旋翼有限偏角减振效果分析

建立了适合带后缘小翼的缩比模型智能旋翼减振优化分析方法。考虑小翼运动引起的气动力和惯性力对旋翼系统的影响,建立带后缘小翼的旋翼气动弹性分析模型,使用一种高效的代理模型方法计算带后缘小翼的翼型气动力。使用隐式梯形公式求解气弹耦合动力学方程得到桨叶的弹性响应,采用力积分法计算桨叶剖面振动载荷与桨毂载荷。以小翼操纵输入为设计变量,以桨毂载荷幅值为目标函数建立优化问题,使用最速下降法求解最佳减振效果对应的小翼偏转规律。结果表明本模型计算的结构与气动载荷可靠,对不同前进比状态,后缘小翼都能有效降低桨毂垂向振动载荷。使用直接约束法和目标权重法都能模拟小翼偏转能力不足的情况,小翼偏转能力对减振效果有明显影响,偏转能力不足时后缘小翼仍具有一定的减振效果。

Vibration Control Analysis of Trailing Edge Flap Smart Rotor with Limited Deflection Angle

An optimization method for vibration reduction of small-scaled smart rotor with trailing edge flaps is presented. Both the inertial forces and aerodynamic forces due to the deflection of trailing edge flaps are concerned in this model. A surrogate model is developed to calculate the aerodynamic forces of flapped airfoils. The aeroelastic dynamic equations are solved with the implicit trapezoid method to get the elastic response of blade, and the vibratory blade loads and hub loads are predicted with a force integration method. The flap deflection harmonics are the design variables and the amplitutes of vibratory hub load are chosen as the objective function. The best flap deflection law for hub vibration control is found with the steepest descent method. Results show that both structural and aerodynamic loads of rotor can be precisely calculated with the current model. Hub vertical vibratory load can be effectively reduced with properly controlled flaps at different advance ratios. The lack of deflection ability can be simulated with the direct constraint method or the objective weight method. The deflection ability of trailing edge flaps significantly influences the vibration reduction effect. Despite the limited deflection angle due to the ability of actuator, vibratory loads can still be reduced with actively controlled flaps.