防旋板高度对迷宫密封泄漏流动和转子动力特性的影响

采用基于转子多频椭圆涡动模型的Unsteady Reynolds-Averaged Navier-Stokes (URANS)方程求解方法,研究了防旋板高度与第1个迷宫齿前缘高度相同时,防旋板高度对迷宫密封泄漏流动和转子动力特性系数的影响.计算分析了典型中等进口预旋条件下,无防旋板结构以及防旋板高度为1.85,3.7和...

Influence of Swirl Brake Height on the Leakage Flow and RotordynamicCharacteristic Coefficients of Labyrinth Seals

By solving the Unsteady Reynolds Averaged Navier Stokes (URANS) solution based on the multi frequency elliptical rotor whirling model, the influence of swirl brake height on the leakage flow and rotordynamic characteristic coefficients of the labyrinth seal was investigated when the swirl brake height equaled to the leading edge height of the first labyrinth tooth. The leakage flow rate, airflow circumferential velocity and rotordynamic characteristic coefficients of labyrinth seals without swirl brake configuration or with swirl brake height of 1.85 mm, 3.7 mm and 7.4 mm were calculated and analyzed under the condition of typical medium inlet preswirl. The research results show that the swirl brake height makes little contribution to the seal leakage. When the swirl brake height equals to the leading edge height of the first labyrinth tooth, the optimum swirl brake height exists, which makes the airflow circumferential velocity in the downstream of swirl brakes the lowest. The increased swirl brake height not only reduces the circumferential pressure fluctuation in the inlet cavity region and then weakens the positive tangential airflow excitation force, but also slightly enhances the magnitude of the negative tangential airflow excitation force in the downstream cavity region of swirl brakes, which contributes to a better rotor stability. The sealed direct stiffness degrades with the increase of swirl brake height in the range of low whirling frequency below 162 Hz.