密封间隙对迷宫密封性能影响的三维数值分析

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At present, two-dimensional model was adopted mainly for the numerical simulation of the labyrinth seal mechanism. In order to simulate the performance of the labyrinth seal more accurately ,the three-dimensional model was es- tablished by considering the influence of circumferential turbulence. The GAMBIT was adopted to divide the labyrinth gap in an unstructured gridding approach, the effect of sealing clearance on the labyrinth seal performance was simulated, and the results were compared with the simulation data of 2D section model. The results show that, in considering the influence of circumferential turbulence, leakage rate is decreased significantly as compared to only considering horizontal and vertical flows, which show that the effects of the circumferential turbulence exacerbated the sealed cavity energy dissipation. The throttling effect of the sealed cavity is significant, and a role is played that cannot be ignored in the overall labyrinth seal performance. Along with the increasing of gap width, the flow velocity and the throttling effect of the labyrinth gap are re- duced, and the leakage rate is increased gradually.目前迷宫密封机制的数值模拟主要采用二维模型。为更准确地模拟迷宫密封的性能，在考虑周向湍流的情况下，建立迷宫密封的三维模型；采用GAMBIT对迷宫间隙进行非结构化网格划分，模拟密封间隙对迷宫密封性能的影响，并与二维截面模型模拟结果进行对比。结果表明：在考虑周向湍流的影响下，泄漏量相对于仅考虑横向及纵向湍流的影响有明显的减少，表明周向湍流的作用加剧了密封腔内的能量耗散，密封腔内节流效应显著，对整体的迷宫密封效果起到不可忽视的作用；随着间隙宽度的增大，流体速度降低，迷宫间隙内的节流效应降低，泄漏量逐渐增大。