基于自由尾迹和升力面方法的双旋翼悬停气动干扰计算

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

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-by-side,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.