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对微型燃气轮机向心涡轮叶轮顶部间隙泄漏流动,在级环境下进行了全三维粘性数值模拟研究.结果表明,轮盖和叶轮叶片顶部之间的相对运动引起的刮削流以及叶轮顶部压力面和吸力面两侧的压差对间隙泄漏流动起主要控制作用,叶顶线速度越高,间隙尺寸越小,刮削作用越强;改变叶轮转速对叶轮中部和导风轮顶部间隙内的泄漏速度影响不大,但是叶轮转速能明显影响通道涡涡核与吸力面之间的距离;间隙泄漏量主要在导风轮顶部区域形成,如布置泄漏抑制结构,在轮盖子午弦长的中后部将是最有效的.
The full three-dimensional viscous numerical simulation was carried out under the cascade environment with the leaking flow at the tip of the centrifugal turbine impeller of the micro gas turbine.The results show that the scraping flow caused by the relative movement between the wheel cover and the top of the impeller and the pressure surface and suction The pressure difference between the two sides of the face plays a key role in controlling the leakage of the gap. The higher the tip-line speed, the smaller the size of the gap, and the stronger the scraping action. The effect of changing the impeller speed on the leakage speed in the middle of the impeller and the top of the impeller is not Large, but the impeller speed can significantly affect the distance between the vortex core and the suction surface of the passage; the leakage of the gap is mainly formed in the top area of the wind turbine. For example, if the leakage suppression structure is arranged, most effective.