摘要
针对离心压气机在近失速工况点运行时,扩压器进口气流角为正攻角,造成其吸力面发生流动分离,从而导致压气机发生失速甚至喘振等问题,为进一步扩大离心压气机的稳定工作范围,需对扩压器近失速工况点的流动分离进行抑制。以某高负荷离心压气机为研究对象,利用经过校核的数值模拟方法开展了扩压器叶片前缘开槽的参数化研究,详细探讨了开槽长度、深度对离心压气机性能、稳定裕度的影响规律,归纳总结了离心压气机扩压器的最佳开槽参数。研究结果表明:随着开槽深度、长度的增加,失速裕度有所提高但压气机性能有所下降;实际设计中开槽深度不应超过叶片高度的9%,最佳开槽长度不应超过叶片弦长的6%~12%;当扩压器开槽深度为叶片高度的3%、开槽长度为叶片弦长的6%~12%时,压气机性能最佳。扩压器开槽可有效抑制其通道内的流动分离,并提高压气机的失速裕度。
When a centrifugal compressor operates near the stall point, the positive incidence angle at the diffuser inlet makes flow separation appear near the diffuser suction side, leading to compressor stall and surge. The leading edge structure of diffuser has an important effect on the compressor’s performance and flow field. To extend stable operating range of centrifugal compressors, the flow separations within the diffuser passage near stall point need to be suppressed. In this research, numerical simulations were performed for a highly loaded centrifugal compressor to investigate the design method of slotted diffuser and discuss the influences of slot length and depth on the stage performance and stall margin. The results indicate that the compressor performance is deteriorated with the increase of slot length and depth, although the stall margin is expanded. In conclusion, the slot depth should not exceed 9% of the diffuser vane height, and the optimal slot length should not be more than 6%-12% of the diffuser chord length, which provides a guideline for slotted diffuser design. When the slot depth is 3% of the diffuser vane height and slot the length is in the range of 6%-12% of the diffuser chord length, the compressor performance is the best. Adopting slotted diffuser is an effective passive flow control strategy for suppressing flow separation in diffuser and expanding compressor stall margin.
作者
张英杰
韩戈
董旭
赵胜丰
张燕峰
卢新根
ZHANG Yingjie;HAN Ge;DONG Xu;ZHAO Shengfeng;ZHANG Yanfeng;LU Xingen(Institute of Engineering Thermophysics,Chinese Academy of Sciences,Beijing 100190,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2019年第9期34-41,共8页
Journal of Xi'an Jiaotong University
基金
国家自然科学基金资助项目(51606187)
关键词
离心压气机
扩压器开槽
数值模拟
失速裕度
centrifugal compressor
slotted diffuser
numerical simulation
stall margin
