二维干净构型、增升构型地面效应的数值模拟研究

Numerical simulation on aerodynamic characteristic of clean and multi-element airfoils in ground effect

通过求解二维非定常雷诺平均N-S方程,使用k-ωSST湍流模型,分析了地面效应对二维干净构型、增升构型失速攻角变化的影响;对移动地面、固定地面条件下两种二维构型的气动特性进行了研究,并探讨了近地高度变化对流场的影响。结果表明:地面效应使得干净构型增升减阻,增升构型减升减阻,但使两种构型的失速攻角均减小;移动地面、固定地面条件下两种构型升阻力变化趋势一致;干净构型小攻角时固定地面条件下的升阻力均稍大于移动地面,而增升构型则呈现升力小于移动地面、阻力高于移动地面的趋势。地面效应对增升构型的影响高度范围较干净构型更广。

By using the k-ω SST turbulence model, the two dimensional unsteady RANS equations are solved, the ground effect on clean airfoil and multi-element airfoil is investigated numerically. The research mainly focuses on the stalling angle of attack, the aerodynamic characteristic in fixed and moving bottom conditions and the influence on different heights between airfoil and the ground. The result obtained indicates that, with the effect of ground, the lift increases and drag decreases for the clean airfoil, but both decrease for the multi-element airfoil, and the stalling angles decrease for both the clean and multi-element airfoils. The variation trends of lift and drag in fixed and moving bottom conditions are the same for the clean and multi-element airfoils, but the lift and drag of fixed ground for clean airfoil seem bigger than that of the moving ground in small angles. For multi-element airfoil, the lift of fixed ground is smaller than that of moving ground, while the drag bigger. Also the result shows that the height ranges of ground effect on the multi-element airfoil can be more widely than the clean airfoil.