变攻角下端壁非定常脉动抽吸对高负荷压气机叶栅性能的影响

Effects of Endwall Unsteady Pulsed Suction on a Highly Loaded Compressor Cascade under Different Incidence Angles

关键词:  非定常脉冲抽吸  高负荷压气机  时均抽吸率  流动分离  攻角

Key words:  Unsteady pulsed suction  Highly loaded compressor  Time-averaged suction flow rate  Flow separation  Incidence angle

摘要:

为进一步探究非定常脉冲抽吸控制高负荷压气机叶栅流动分离的机理，考察非定常脉动抽吸在变攻角下的适应性和可行性，采用非定常数值方法，系统研究了变攻角下，非定常脉动抽吸对流场性能的影响，并将其与传统的定常抽吸进行了比较分析。结果表明，在设计攻角下，保证相同的时均抽吸量，非定常脉动抽吸控制效果明显优于定常抽吸；在时均抽吸量m_s=0.4%时，在给定的激励频率范围内，非定常脉动抽吸都展现出更好的性能，在最优频率时，损失减小了9.4%，静压升提高了12.9%，相比于定常抽吸损失减小了4.2%，静压升提高了4.7%。在变攻角下，在给定的激励频率范围内，非定常脉动抽吸控制效果相比于定常抽吸仍具有较大优势；但大攻角下，非定常脉动抽吸和定常抽吸控制效果均有所下降。

Abstract:

In order to further explore the mechanism of unsteady pulsed suction (UPS) to control flow separations in a highly loaded compressor cascade and investigate the adaptability and flexibility of UPS under different incidence angles, the effects of UPS on flow field performances under different incidence angles are studied systemically by numerical simulation, and the comparative analysis between UPS and conventional steady contant suction (SCS) is carried out. The results show that the control effect of flow separations for UPS under the designed incidence angle is obviously better than that for SCS with the same time-averaged suction flow rate. UPS shows better performances in a given range of excitation frequency with the time-averaged suction flow rate m_s=0.4%, based on the optimum excitation frequency for UPS, the loss is reduced by 9.4% and the static pressure rise coefficient increased by 12.9%, and compared to SCS, the loss is reduced by 4.2% and the static pressure rise coefficient increased by 4.7%. UPS has still a greater advantage compared to SCS in a given range of excitation frequency under different incidence angles， however, the control effects of UPS and SCS are decreased under a large incidence angle.