微型飞行器小展弦比薄翼流场中的翼尖涡特性分析

Analysis of wingtip vortex characteristics in flows around low-aspect-ratio thin wings for micro air vehicles

采用虚拟压缩方法求解三维不可压缩N-S方程,数值模拟了无弯度、有弯度两类微型飞行器低雷诺数小展弦比薄翼的流场,将得到的结果与实验进行了对比,数据间吻合较好。然后在此基础上分析了小展弦比薄翼的气动力特性,详细研究了小展弦比薄翼流场中翼尖涡的涡态结构及形成规律,在对小展弦比薄翼流场尾迹区的翼尖涡采用近似模型的基础上,对尾迹区翼尖涡的强度进行了分析。结果表明,翼尖涡是影响小展弦比薄翼气动力和流动分离特性的一个重要因素。

The three-dimensional incompressible Navier-Stokes equations are solved by artificial compressibility approach, the flows around two kinds of low-aspect-ratio thin wings for Micro Air Vehicles, flat and cambered, are simulated at low Reynolds number, numerical results agree well with the experimental data. Then the aerodynamic characteristics of low- aspect-ratio thin wings are analyzed, The structure and formation of wingtip vortex in flows around low-aspect-ratio thin wings are studied in all details. Based on the approximate model of wingtip vortex, the strength of wingtip vortex in wake region of low-aspect-ratio wings flows is also analyzed. Results show that wingtip vortex is an important factor to affect the aerodynamics and flow separation of low-aspect-ratio thin wings.