Gurney襟翼对多段翼型气动性能影响的数值研究

采用剪切应力输运（SST）k-ω两方程湍流模型和C-H型多块结构网格求解二维非定常雷诺平均Navier-Stokes方程，结合襟翼缝道参数变化研究了不同形式的Gurney襟翼（GF）及其几何参数对多段翼型气动性能的影响，GF形式包括主翼和襟翼分别及同时增加GF。在GF绕流数值计算中对GF局部网格进行适当加密，多段翼型不同襟翼缝道参数GF构型的计算结果表明：主翼GF的影响主要取决于缝道参数，通过减小襟翼逆压梯度可以有效抑制襟翼位置并非最优时出现的流动分离，因而能够用来重新优化缝道参数；襟翼GF对基本构型的影响大致相同，升力系数和俯仰力矩系数增加明显且随GF高度非线性变化，但当其高度合适时阻力系数变化不大；主翼和襟翼同时增加GF时，在线性区域内多段翼型气动性能的变化大致为上述两种单独情形的线性迭加。

Numerical Investigation of Effects of Gurney Flaps on Aerodynamic Performance of Multi-element Airfoils

The 2D unsteady Reynolds-averaged Navier-Stokes equations together with the two-equation shear stress transport (SST) k-ω turbulence model are applied to the multi-block structured grids of a C-H type to investigate the effects of various Gurney flaps (GF) and their geometry parameters on the aerodynamic performance of multi-element airfoils for different flap riggings, including the main GF, the flap GF and the combination GF. The numerical results for different flap riggings of the multi-element airfoil show that the impact of the main GF mainly depended on the slot parameters. By reducing the adverse pressure gradient, the main GF could effectively eliminate flow separation on the flap when it is in a non-optimum position; therefore it could be used to re-optimize the slot parameters. The influence of the flap GF on the baseline configurations with different flap riggings is nearly identical. The lift coefficient and nose-down pitching moment coefficient are significantly increased in non-linear variation, but the drag coefficient changed little if the height of the flap GF is appropriate. In the linear region the combination GF on the main element and flap is approximately a linear combination of the changes caused by the two individual GFs.