基于自由尾迹和升力面方法的双旋翼悬停气动干扰计算

An analytical method for aerodynamic interactions of twin rotors based upon free-vortex and lifting-surface models

建立了一个同时适合于共轴式、横列式及纵列式直升机双旋翼气动干扰分析的计算方法。在该方法中,为更好地模拟气动干扰特性及桨尖三维效应,桨叶模型采用了升力面/涡格法,尾迹则使用畸变的自由尾迹模型。通过旋翼下洗速度的计算值与可得到的实验值对比,验证了计算方法的有效性。应用该方法,以横列、共轴、纵列式双旋翼为例,分别计算了悬停状态双旋翼的尾迹特性及诱导速度变化,给出了部分尾迹边界,并对计算结果进行了分析。最后,给出了几点结论。

An analytical method was developed for the prediction of aerodynamic interactions between twin rotors for coaxial, side-by-side and tandem configurations. In order to simulate better interactional aerodynamic characteristics and 3- D tip effects, the analytical method has combined a lifting-surface/vortex-lattice blade model with a free-vortex wake model. The OH-13E rotor was used as numerical examples, and the comparison between calculated results and available experimental data has validated the computational method. Then, the aerodynamic interactions between the twin rotors for side-byside, tandem and coaxial helicopter configurations were calculated and analyzed on wake geometries and induced velocities for hovering flights, and based upon the calculations, several conclusions were presented.