小型无人直升机超低空飞行时下洗流场数值分析

为了研究小型植保无人直升机超低空飞行时下洗流场的特征,利用SolidWorks软件和Ansys Workbench软件建立全尺寸物理模型并抽取外流场,使用ICEM软件对模型进行网格划分,运用Fluent软件对小型无人机超低空飞行进行三维数值模拟研究.数值分析结果表明:小型无人直升机超低空飞行时下洗流场的主要运动形式为垂直向下运动,同时伴随有周向旋转运动和径向收缩运动;在旋翼0.8R(R为旋翼半径)位置下方,下洗流场速度最大;随着高度的降低,下洗流场速度逐渐减小,水平方向速度分布逐渐趋于平缓.获得的下洗流场数据为小型植保无人机的设计提供了参考依据.

Numerical simulation for downwash flow field of small-size unmanned helicopter hedgehopping

In order to explore the downwash flow field characteristic of small-size unmanned helicopter hedgehopping, numerical simulations were conducted.The full-size physical model of the small-size helicopter was established by SolidWorks software. The outer flow field and meshing were established by Ansys Workbench software and ICEM software.Three-dimensional flow field of small-size unmanned helicopter hedgehopping was simulated by Fluent software.The results show that in the downwash flow field,the main movement form is vertical,accompanied by circumferential rotation and radial shrinkage.The maximum velocity appeared at the bottom of the location of 0.8R(R is the radius of the rotor)far from the axis of rotor rotation.With the vertical height declining,the maximum velocity and velocity gradient decrease.The acquired flow field can serve as a design referernce for a small-size unmanned helicopter.