螺旋桨滑流对菱形翼布局无人机气动的影响

采用基于混合网格技术及k-k_L-ω转捩模型求解雷诺平均Navior-Stokes （RANS）方程的多重参考系（MRF）方法对带桨状态的低雷诺数菱形翼布局无人机（UAV）的气动特性进行了准定常数值模拟，通过对无人机带桨状态和干净构型的气动力系数及流场结构特性进行对比分析，研究了螺旋桨在不同安装位置时其滑流对菱形翼布局无人机气动特性的影响。研究结果表明，螺旋桨滑流并不总能提高无人机的升力特性；螺旋桨安装在机头及前翼时后翼受到螺旋桨滑流形成的组合涡系的影响，其气动性能有较大的变化；螺旋桨滑流对机翼的增升作用还受到机翼掠角和螺旋桨旋转方向的影响；受布局特性影响，当安装位置远离焦点时，螺旋桨滑流对无人机的俯仰力矩特性影响较大。

Effects of propeller slipstream on aerodynamic performance of diamond joined-wing configuration UAV

The aerodynamic characteristics of the low Reynolds number diamond joined-wing configuration Unmanned Aerial Vehicle (UAV) with propellers is numerically simulated by quasi-steadily solving the Reynolds Averaged Navior-Stokes (RANS) equations of Multiple Reference Frames (MRF) based on the hybrid grid technology and k-k_L-ω transition model. The influence of the slipstream on the aerodynamic characteristics of the diamond joined-wing configuration UAV at different installation positions is studied by comparing the aerodynamic coefficients and the flow field characteristics of the UAV with propellers and with the clean configuration. The results show that the propeller slipstream does not always improve the lift characteristics of the UAV. The aerodynamic performance of the Aft-wing (after wing) is affected by the combination vortex formed by the propeller slipstream when the propeller is installed in the nose and Frt-wing (front wing). The effect of the propeller slipstream on the wing is also affected by the wing sweep angle and propeller rotation. Affected by layout characteristics, the propeller slipstream has a great influence on the pitching moment characteristics of the UAV when the installation position of the propeller is away from the focus.