二维紊流场对飞艇水平面内运动影响研究

大气紊流是影响高空飞艇水平面内巡航的重要原因,传统Dryden模型采用谱分解定理,只能生成一维大气紊流模型,对于高空飞艇复杂的飞行运动来说,生成二维紊流风场模型是必要的.基于紊流场的空间相关特性,采用离散自递归方法构建风场模型,然后结合风速矢量三角形关系式,建立扰动下的飞艇动力学模型,再对该模型进行水平竖直解耦.仿真结果表明,大气紊流作用在飞艇上的力会使飞艇较大程度地偏离其运动航迹,呈不稳定的随机波动状态.因此,构建高空飞艇动力学模型时,要充分考虑大气紊流的影响.

Study for the Horizontal Movement of Airship under the Two-dimensional Turbulence

Atmospheric turbulence is a key factor that affects airship fixed-point hover. When building the turbulent flow model, the Dryden model based on the spectral decomposition theorem is adopted. But the traditional method only generate one-dimensional atmospheric turbulence model. It is necessary to build two-dimensional atmospheric turbulence model for the complex flight movement of the airship. Firstly, a recursive model of two-dimensional turbulence based on the space-related function is adopted to construct the wind field in this paper. Secondly, the dynamic model of the airship under the disturbance of the wind field is built according to the wind velocity triangle relationship. And then the model is decoupled in the horizontal and vertical direction. The simulation results indicate that the forces of wind acting on the airship will make it deviate from the flight trajectory comparing with no wind. Therefore, the paper conforms that turbulence effect needs to be considered when the dynamic model of airship is constructed