端壁抽吸对压气机叶栅间隙泄漏流控制策略的研究

Research on Tip Leakage Flow Control Strategy for Compressor Cascade with Casing Aspiration

关键词:  压气机叶栅  间隙泄漏流  端壁抽吸  抽吸流量率  数值模拟

Key words:  Compressor cascade  Tip leakage flow  Casing aspiration  Aspiration flow rate  Numerical simulation

摘要:

为了研究压气机机匣端壁抽吸对间隙泄漏流动控制的可行性和有效性，以高负荷压气机叶栅为研究对象，通过数值模拟方法对不同抽吸位置和抽吸流量率控制参数下的计算工况进行了对比和分析。研究结果表明：端壁抽吸可以直接地影响叶尖泄漏流的结构形态和存在形式，减弱叶尖泄漏流的强度和影响范围，进而提升压气机叶栅的性能；当抽吸槽覆盖范围包含叶尖泄漏流形成位置及稍靠后附近区域时，所对应的抽吸方案具有较好的控制效果，在0°攻角和0.5%的抽吸流量条件下前槽抽吸和中槽抽吸分别可获得7.04%和7.76%的叶栅总压损失增益；并且进一步研究发现端壁抽吸流量率存在上临界值，应针对不同攻角工况，在其相应的临界值范围内选择合理的抽吸流量，以达到用较小的吸气量实现对间隙泄漏流的控制。

Abstract:

In order to study the feasibility and validity of casing aspiration in controlling the tip leakage flow for the compressor cascade, comparison and analysis of the results of numerical investigations are performed on a highly-loaded axial compressor cascade in different controlling parameters of aspiration location and flow rate. The results show that casing aspiration can directly affect the structure and existing form of the tip leakage flow, and reduce the overall intensity and extent, thereby improving the cascade performance effectively. An optimum aspiration scheme which has a good control effect should cover the area including the onset point of tip leakage flow and its vicinity. The total loss coefficient is reduced by about 7.04% and 7.76% at the incidence of 0° and aspiration flow rate of 0.5%, respectively, for forepart and mid-part aspiration scheme. And further work showed that the aspiration rate has an upper critical value. A reasonable aspiration flow rate should be selected within the corresponding critical value range for different incidence conditions in order to control the tip leakage flow with a small aspiration.