端壁射流对压气机叶栅角区分离控制的研究 *

Research on Corner Separation Control for Compressor Cascade with End-Wall Jet Flow

关键词:  压气机叶栅  端壁射流  角区分离  通道涡和角涡  壁面摩擦系数

Key words:  Compressor cascade  End-wall jet flow  Corner separation  Passage and corner vortex  Skin friction coefficient

摘要:

为了研究端壁射流对压气机叶栅端壁角区分离控制的可行性和有效性，以压气机叶栅为研究对象，基于数值模拟方法对不同射流角和射流比控制参数下的计算工况进行了对比和分析。研究结果显示:端壁射流可以有效地控制角区的分离和降低叶栅损失，提高了叶栅的流通能力；控制效果受射流角和射流比的影响，只有射流控制参数大于临界射流角和临界射流比时，角区分离的控制效果才会显著，在10°射流角和0.23%的射流比条件下可以获得33.4%的相对叶栅损失增益；端壁射流在较大射流比下可以有效削弱通道涡、角涡的强度，阻断了其与尾缘脱落涡的接触，降低了涡系间相互作用导致的高损失影响；由于流道角区阻塞度的减小，叶展中部截面的损失和出气角会有少量增加。

Abstract:

In order to study the feasibility and validity of end-wall jet in controlling the corner separation for the compressor cascade，comparison and analysis of the results of numerical investigations are performed on a compressor cascade in different controlling parameters of jet angle and jet ratio. The results show that end-wall jet flow can control the corner separation effectively and reduce the loss of cascade resulting in the increase of mass flow. The control effectiveness is influenced by the jet angle and jet ratio and it will be remarkable when the controlling parameters are greater than their critical values. About 33.4% relative loss gain can be obtained when assigning the jet angle and jet ratio value as 10°and 0.23% respectively. End-wall jet flow with a larger jet ratio can weaken the strength of passage vortex and corner vortex and cut off the contact among the trailing edge shedding vortex，passage vortex and corner vortex. Therefore，this can reduce the great loss resulting from their interaction. The loss and exit flow angle in the mid-span of cascade will be slightly larger because of the reduction of the passage blocking.