一种低速风洞虚拟飞行试验装置的建模与仿真

Modeling and simulation for a low speed wind tunnel virtual flight test rig

为实现大角度范围、多自由度的机动动作模拟,研发一种低速风洞三自由度动态试验支撑机构,可模拟绕速度矢滚转机动动作以及失速偏离、尾旋等危险飞行状态。该机构通过两自由度转台和旋转曲杆的组合运动模拟飞机模型的三轴姿态变化。基于多体动力学理论,采用拉格朗日乘子法推导出该机构曲杆-飞机模型的动力学数学模型;模型中考虑了机构与试验模型的约束关系、机构摩擦力矩的影响。仿真结果表明:采用该支撑机构,飞机模型可在水平风洞中实现绕速度矢量滚转等典型机动动作;曲杆和试验模型的滚转运动基本同步;曲杆主要影响速率响应的动态过程,摩擦力矩对速率的动态过程和稳态值有一定影响。以上数学建模和仿真验证可为风洞试验提供理论依据。

In order to realize the maneuver simulation of large angle and multi-degree-of reedom,a three degree-of-freedom dynamic test r ig, which enables simulation of the velocity vector rol l and uncontrolled f l ig ht condition such as stal//departure/sp in, is developed to solve the aerodynamic/motion coupling issues. The rotational motion of the three axis of the aircratt model is simulated by the combined motion of the 2-DOF gimbal. Based on multi-body dynamics theory,the dynamical equation of the curved rod and aircratt model w ith terms accounting for friction in the gimbals is obtained with Lagrange m u lt ip l ie r method. The simulation results show that,the rig can provide the a b i l ity to realize the velocity vectorroll, and the rotation of thecurved rod is synchronous with the rolling motion of the aircraft model. The curved rod has aneffect on the dynamic response of rotational rates,while the frict ion al torque makes a difference on both the dynamic response and steady state value of rotational motions. The mathematical model and simulation validation provides a guide fo r wind tunnel test.