[关键词]
[摘要]
为研究冷气孔流量对涡轮叶尖泄漏流动的作用,采用数值模拟方法对比分析冷气流量比在0.05%~3%之间的三维流场和总压损失情况。结果表明:叶尖冷气可以有效地减小泄漏量和叶尖泄漏流动带来的总压损失,泄漏量下降达80%,总压损失峰值下降达38.2%;随着流量比的增加,叶尖冷气对叶尖主流泄漏流动的抑制效果不断增强,由主流带来的泄漏量不断减小;叶尖冷气也带来了新的总压损失,整体总压损失随着流量比的增加不断增大。叶尖冷气对叶尖泄漏的抑制模式分为3种:流量比在0.05%~0.1%之间,以降低主流泄漏流的能量减弱泄漏流动;流量比在1.25%~3%之间,以在叶尖区域形成完整的气膜屏障抑制主流泄漏流动,流量比在0.1%~1.25%之间,上述两种模式同时存在;流量比为1.25%时,冷气在叶尖区域形成一道完整的气膜屏障,阻碍主流流体形成泄漏流。
[Key word]
[Abstract]
In order to study the effect of the flow rate of the cooling air hole on the leakage flow of the turbine blade tip,a numerical simulation method was used to compare and analyze the threedimensional flow field and total pressure loss under the cooling air flow ratio between 0.05% and 3%. The results show that the tip cooling air can effectively reduce the leakage quality and the total pressure loss caused by the tip leakage flow,the leakage quality is reduced by 80%,and the peak value of total pressure loss is reduced by 38.2%; with the increase of the flow ratio,the inhibition effect of the blade tip cooling air on the leakage flow of the blade tip mainstream is continuously enhanced,and the amount of leakage caused by the mainstream continues to decrease. At the same time,tip cooling air also brings new total pressure loss and the overall total pressure loss increases with the increase of flow ratio continually. There are three inhibition modes of tip cooling air on tip leakage,such as by reducing the energy of the mainstream leakage flow to weaken the leakage flow under cooling air flow ratio between 0.05% and 0.1%,by forming a complete air film barrier in the tip area to inhibit the mainstream leakage flow under cooling air flow ratio between 1.25% and 3% and the above two exist at the same time under cooling air flow ratio between 0.1% and 1.25%. When the cooling air flow ratio is 1.25%,the cooling air forms a complete air film barrier in the blade tip area,which prevents the mainstream fluid from forming leakage flow.
[中图分类号]
V232.4
[基金项目]
中央高校基本科研业务费中国民航大学专项(3122019169)