开缝空腔抑制翼型跨声速抖振的数值模拟

Numerical simulation of transonic airfoil buffet suppression with slotted cavity

采用非定常雷诺平均Navier-Stokes(URANS)方法计算了18%双圆弧翼型的跨声速抖振特性,分析了翼面激波振荡及流场结构演化的特点,研究了在翼型表面开通气空腔抑制跨声速抖振的可行性,对空腔深度、开缝数目对激波振荡的抑制效果进行了对比分析。计算发现,18%双圆弧翼型的跨声速激波自激振荡只有向前的运动,没有向后的运动,开缝空腔能够抑制翼型跨声速抖振,但对抖振频率影响不大;空腔深度大,抑制效果好,但空腔深度变化对振荡频率影响不大;开2、3、4个槽缝抑制抖振的效果差别不大,开缝数量对抖振频率影响不大。

The unsteady Reynolds average Navier-Stokes （URANS） method is used to compute the transonic buffet, the shock oscillations and the evolution of flow structures of 18 % thick biconvex circular-arc airfoil. The suppression effects of passive control with different configurations on transonic airfoil buffet are investigated by numerical method. The computa- tional results reveal that the self-sustained shock oscillation on 18 % thick biconvex circular-arc airfoil at transonic speeds has only forward motion without noticeable backward motion. A cavity with ventilating slots, as a passive control measure, can alleviate transonic buffet, but has little influence on the buffet frequency. Deeper cavity has greater effect of suppression but the variation of the cavity depth does not influence the buffet frequency. The suppression effects between 2-slot, 3-slot and 4-slot cavities are insignificant and the number of slots has little influence on the buffet frequency.