一种减小涡轮叶尖泄漏流的方法
Method for reducing tip clearance leakage of turbine
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摘要: 提出了一种叶尖逆向涡流发生器减小叶尖泄漏流的方法,利用压力面和叶顶面的压力差,将气流从压力面引入,从叶顶面逆着叶尖泄漏流方向高速射出减小叶尖泄漏流.对某典型毫米尺度涡轮叶栅进行了有/无逆向涡流发生器流场的数值对比分析,分析了不同进口条件下逆向涡流发生器对叶尖泄漏流和周向载荷的影响.结果发现:在典型进口条件下,逆向涡流发生器使得叶尖间隙泄漏流量降低了3.3%,周向载荷升高了6.2%;进口马赫数越小,涡流器对泄漏流量的减小效果越好;而进口马赫数越大,涡流器对叶片周向载荷的提高越明显.进口马赫数增大,该方法对涡轮效率的提高越大.Abstract: A kind of method for reducing tip clearance leakage of turbine was presented using backward vortex generators (BVGs) in this paper.In order to reduce tip leakage flow,the gas is guided to flow into BVGs from pressure side of blade and flow out of blade tip with high speed in the inverse-direction of leakage flow,based on the pressure difference between pressure surface and blade tip.Numerical simulations of typical turbine cascade in millimeter scale with/without BVGs were performed and the influences of BVGs on mass of leakage flow and circumferential load were analyzed.The results show that mass of leakage flow decreases by 3.3% and circumferential load increases by 6.2% in typical entrance condition.Moreover,the smaller entrance Mach number means the better effect of reducing mass of leakage flow;the larger entrance Mach number means more obvious improvement of circumferential load.When entrance Mach number increases,the improvement of turbine efficiency grows.
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Key words:
- leakage flow /
- tip clearance /
- turbine /
- backward vortex generator /
- circumferential load /
- turbine efficiency
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