耦合滑流太阳能无人机阵风响应特性研究

针对太阳能无人机因追求极致的飞行效率,使得翼载荷越来越小、导致突风敏感的问题,采用多重参考坐标系法和网格速度法,对时变风场中耦合螺旋桨滑流影响的低雷诺数菱形翼布局太阳能无人机阵风响应特性进行了研究。首先,对多重参考坐标系法、网格速度法及低雷诺数数值模拟法进行了数值验证;接着,对菱形翼布局太阳能无人机时变风场中三个不同迎角下有无动力构型的阵风响应进行了数值模拟。研究表明:带动力构型升力系数阵风响应增量在各个迎角下均大于干净构型;随着阵风干扰幅值的增大,机翼的有效迎角逐步增大,带动力构型螺旋桨滑流影响逐步增强,桨后层流分离泡逐步消失;在滑流下洗区域,前缘负压力峰值逐步消失,上洗区域最大压力系数幅值相比干净构型大幅增加。

Research on gust response characteristics of solar-powered UAV coupling with propeller slipstream

In order to pursue high flight efficiency,the wind load of solar powered UAV is getting smaller,which induces gust sensitivity.Based on this background,multiple reference frame method and grid velocity method were used to analyze the gust response characteristics of diamond joined-wing configuration solar powered UAV coupling with propeller slipstream at low Reynolds number in time-varying wind field.First,the reliability of the multiple reference frame method,grid velocity method and numerical simulation method at low Reynolds number were verified.Then,the gust response with or without dynamic configuration at different angles of attack were numerically simulated.The results show that the lift coefficient of dynamic configuration is greater than that of the clean configuration.With the increase of gust amplitude,the effective angle of attack of wing increases,and the effect of propeller slipstream increases as well.The laminar flow separation bubble gradually disappears as well as the negative pressure peak at the leading edge in the slipstream washing area.The maximum pressure coefficient amplitude increases significantly in the upper washing area compared with the clean configuration.