适用于直升机飞行力学分析的三维空间大气紊流模型

A Model of Three-dimensional-field Atmospheric Turbulence for Helicopter Flight Dynamics Analysis

发展了一种新的适用于直升机飞行力学分析的三维空间大气紊流模型。采用Dryden紊流模型生成给定空间点的时域离散紊流速度,在速度坐标系框架下,横向和垂向采用统计特性守恒的高斯插值法进行紊流场空间扩展,而沿速度的纵向采用时间序列延迟法扩展紊流场,最终形成覆盖直升机各个气动面的三维空间大气紊流速度场。将本文计算结果和国外经过飞行仿真验证的二维空间紊流模型结果进行对比分析,验证本文模型的有效性和正确性,研究二维和三维空间紊流模型的区别。结果表明:本文模型改善了二维空间大气紊流模型对俯仰角速度、横向速度和航向角速度响应计算幅值偏小的缺陷;紊流引起的直升机响应幅值随飞行速度和紊流强度的增加而增大,随飞行高度的增加而减小。

In this paper, we develop a new three-dimensional-field turbulence model for helicopter flight dynamics analysis. The given points＇ discrete turbulence velocities in time domain are generated with the Dryden turbulence model and are ex- panded into a three-dimensional atmospheric turbulence field, which covers the helicopter＇s all aerodynamic components in the airspeed coordinate system, by the time transport delay method in the longitudinal airspeed direction and the Gaussian interpolation method, which keeps the turbulence＇s statistical properties, in the lateral and vertical directions. The model＇s calculation results obtained in this paper and the two-dimensional-field turbulence model＇s results, which are validated by a piloted simulation, are compared and analyzed to validate the accuracy and precision of the three-dimensional-field turbu- lence model, and the differences between the two-dimensional-field and the three-dimensional-field turbulence models are re- searched. The results show that the proposed model overcomes the two-dimensional-field turbulence model＇s disadvantages that the calculation values of pitching angle velocity, lateral velocity and course angular velocity are small; the amplitudes of helicopter response become bigger as flight speed or turbulence intensity increases, smaller as the turbulence scale increases.