以固定机翼式微型飞行器(miniature air vehicle, MAV)的气动设计为研究背景, 对小展弦比低雷诺数下不同长短轴比值(long-short axis ratios, LSARs)的齐默曼和反齐默曼机翼流场进行数值分析. 采用人工压缩性方法求解不可压粘性绕流, 应用三阶迎风格式离散对流项, 湍流模型为Baldwin-Barth一方程模型. 通过对比齐默曼和反齐默曼两种布局机翼的数值结果与实验值, 验证了数值方法的正确性. 通过分析不同长短轴比值齐默曼和反齐默曼机翼的气动性能, 揭示出在长短轴比值相同的情况下, 反齐默曼机翼有较高的升力, 且其升阻比随着长短轴比值的减小而增大.
Based on the areodynamic design of fixed wings for miniature air vehicle (MAV), the flow fields of Zimmerman and inverse Zimmerman wings with different long-short axis ratios (LSARs) are investigated numerically under low Reynolds numbers. The uncompressible viscous flow is solved by the eudocompressibility formulation. A third-order upwind scheme was used to discretize the convective terms based on Roe's approximate Riemann solver. The Baldwin-Barth one-equation turbulence model is used. Numerical results for Zimmerman and inverse Zimmerman wings agree well with the experimental data, showing correctness of the numerical methods. In this paper, the effect of different long-short axis ratios on areodynamic characteristics of two wing layouts is analyzed. The result shows that inverse Zimmerman has better lift coefficient than Zimmerman’s for the same LSAR, and the L/D coefficient is increased as the LSAR is decreased.
[1] Torres G E, Mueller T J. Low-aspect-ratio wing aerodynamics at low Reynolds numbers [J]. Journal of Aircraft, 2004, 42(5): 865-873.
[2] 李占科, 宋笔锋. 两种布局微型飞机的风洞试验研究[J]. 实验流体力学, 2006, 20(1): 72-74.
[3] 李建华, 李锋, 石文. 微型飞行器相关布局气动特性实验研究[J]. 空气动力学学报, 2006, 24(4): 498-501.
[4] 王超, 沈怀荣. 低雷诺数条件下微型无人机机翼形状的研究[J]. 飞机设计, 2009, 29(4): 13-17.
[5] 冉景洪, 刘子强, 白鹏. 相对弯度对低雷诺数流动中翼型动态气动力特性的影响[J]. 计算力学学报, 2010, 27(1):88-94.
[6] Chorin J A. A numerical method for solving incompressible viscous flow problems [J]. Journal of Computational Physics, 1997, 135(2): 118-125.
[7] Rogers S E, Kwak D. Steady and unsteady solutions of the incompressible Navier-Stokes equations [J]. AIAA Journal, 1989, 29(4): 603-610.
[8] Rogers S E, Kwak D. An upwind differencing scheme for the steady-state incompressible Navier-Stokes equations [R]. NASA-TM-101051, 1988.
[9] Sherrie L K, Robert T B, Christopher L R. CFL3D USER’S Manual [R]. NASA-TM-208444, 1998.
[10] Baldwin B S, Barth T J. A one-equation turbulence transport model for high Reynolds number wallbounded flows [R]. NASA-TM-102847, 1990.
[11] Pelletier A, Mueller T J. Low Reynolds number aerodynamics of low-aspect-ratio, thin/flat/camberedplate Wings [J]. Journal of Aircraft, 2001, 37(5): 825-
832.
[12] 杨爱明, 翁培奋. 基于迎风格式的双曲型网格生成方法[J]. 空气动力学学报, 2004, 22(1): 109-113.
