盒式翼无人机气动特性数值计算分析

传统方法求解盒式翼无人机的气动特性有一定的局限性,某无人机采用负交错的盒式翼布局,翼尖高差约为5%展长,翼面系统各部件之间的干扰影响复杂。为了获得其失速特性、升降舵效率等粘性作用强烈的边界气动特性,通过雷诺平均Navior-Stokes方法分析其极曲线、失速特性和俯仰力矩特性。结果表明:诱导阻力相对同等单翼降低约9%,与理论结果接近;后翼采用-4°的有效负安装角,导致配平后最大升力系数降低较多;大迎角失速时出现抬头力矩,与前翼后掠导致的翼尖失速以及后翼位于前翼尾流中效率降低有关。

The numerical investigation on aerodynamic characteristics of box wing Unmanned Aerial Vehicle

Solving aerodynamic characteristics of box-wing unmanned aerial vehicle（UAV）by traditional methods is of certain limitations .For a box-wing UAV using negative stagger and wing tip gap of 5% wing span ,the strong interference exist between components of the wing systems .In order to study boundary aerodynamic characteristics effected strongly by viscous interaction of box-wing UAV ,which concludes stall characteristics and efficiency of elevator etc .,Reynolds Averaged Navior-Stokes scheme is adopted to analyze its drag polar , stall and pitching moment characteristics .The research reveals that the induced drag is reduced by 9% com-pared with equal mono-wing ,which is close to the theoretical result ;The trimmed maximum lift coefficient drops significantly due to the requirements of static stability and trim ,which are realized by -4＆#176; negative instal-ling angle of aft wing ;Nose up pitching moment is observed at large angle of attack after stall ,which attributes to the forward wing tip stall due to its sweptback ,as well as the decreased efficiency of the aft wing in the wake of the forward wing .