高负荷压气机叶栅开缝射流分离控制效果研究

Effects of Separation Control Using Slot Jet Approach in Critically Loaded Compressor Cascade

关键词:  压气机叶栅  高负荷  缝隙射流  流动控制  叶栅分离

Key words:  Compressor cascade  Highly loaded  Slot jet  Flow control  Cascade separation

摘要:

为了控制高负荷压气机叶栅分离，设计了一种弧线型缝隙射流方法，通过叶栅实验予以验证。结果显示，缝隙射流显著的减小了叶栅尾缘分离的宽度，提高了分离区内的气流速度，降低了叶栅流动损失；抑制了叶栅内复杂的端壁二次流，使出口流场更加均匀。在0°，3°和6°攻角下，叶栅的平均损失系数降低了7.0%，32.1%和32.3%，平均气流转折角提高了4.02°，3.59°和1.78°。在-3°攻角下，平均气流转折角提高了0.59°，但叶栅损失系数提高了12.3%。可见在分离条件下，缝隙射流极大提高了叶栅气动性能，但在无分离条件下会引起额外的损失。在整个攻角范围内，开缝叶栅保持了不低于原型叶栅设计点的静压升系数，且稳定工作范围扩宽了至少3°攻角。

Abstract:

To reduce the separation of critical load compressor cascade， a slot jet approach is developed using an arc-curve slot. Cascade experiments were conducted to check the effects. Results show that the slot jet significantly reduces the width of trailing edge separation， improves the velocity of separated flow， and reduces cascade flow loss. The jet flow also suppresses the complex end wall secondary flow， leading to a more ordered outflow. At incidences 0°， 3° and 6°， the averaged loss coefficient reduces by 7.0%， 32.1% and 32.3%， while the averaged flow turning angle increases by 4.02°， 3.59° and 1.78°. At incidence -3°， the averaged flow turning angle increases by 0.59°， but the averaged cascade loss coefficient increases by 12.3%. Therefore， the slot jet enables to improve the cascade performance apparently at separation condition， but slightly increases loss at non-separation condition. Within all the incidences， the static pressure rise coefficient of the slotted cascade remains not lower than the design point of the baseline， and its stable operating incidence enlarges more than 3°.