文献类型：期刊文献

中文题名：Numerical Investigation on the Self-Induced Unsteadiness in Tip Leakage Flow of a Micro-Axial Fan Rotor

英文题名：Numerical Investigation on the Self-Induced Unsteadiness in Tip Leakage Flow of a Micro-Axial Fan Rotor

作者：Chen Jinxin[1];Lai Huanxin[1]

机构：[1]E China Univ Sci & Technol, Sch Mech & Power Engn, Shanghai 200237, Peoples R China

年份：2015

卷号：24

期号：4

起止页码：334

中文期刊名：Journal of Thermal Science

外文期刊名：JOURNAL OF THERMAL SCIENCE

收录：;EI(收录号：20153001051675);Scopus;WOS:【SCI-EXPANDED(收录号:WOS:000357442500004)】；CSCD:【CSCD2015_2016】；

基金：This study is funded by the National Natural Science Foundation of China under Grant 50876031 and by Shanghai Municipal Education Commission under Grant 10ZZ40.

语种：英文

中文关键词：micro-axial fan; tip leakage flow （TLF）; self-induced unsteadiness; secondary flow; mechanism.

外文关键词：micro-axial fan; tip leakage flow (TLF); self-induced unsteadiness; secondary flow; mechanism

摘要：The self-induced unsteadiness in tip leakage flow(TLF)of a micro-axial fan rotor is numerically studied by solving Reynolds-averaged Navier-Stokes equations.The micro-axial fan,which is widely used in cooling systems of electronic devices,has a tip clearance of 6%of the axial chord length of the blade.At the design rotation speed,four cases near the peak efficiency point(PEP)with self-induced unsteadiness and four steady cases which have much weaker pressure fluctuations are investigated.Using the"interface"separating the incoming main flow and the TLF defined by Duet al.[1],an explanation based on the propagation of the low energy spot and its multi-passing through the high gradient zone of the relative total pressure,is proposed to clarify the originating mechanism of the unsteadiness.At the operating points near the PEP,the main flow is weaker than the TLF and the interface moves upstream.The low energy spot which propagates along in the close behind of the interface has opportunity to circulate in the circumferential direction and passes through the sensitive interfaces several times,a slight perturbation therefore may be magnified significantly and develops into the self-induced unsteadiness.The explanation is demonstrated by numerical results.
The self-induced unsteadiness in tip leakage flow (TLF) of a micro-axial fan rotor is numerically studied by solving Reynolds-averaged Navier-Stokes equations. The micro-axial fan, which is widely used in cooling systems of electronic devices, has a tip clearance of 6% of the axial chord length of the blade. At the design rotation speed, four cases near the peak efficiency point (PEP) with self-induced unsteadiness and four steady cases which have much weaker pressure fluctuations are investigated. Using the "interface" separating the incoming main flow and the TLF defined by Du et al. [1], an explanation based on the propagation of the low energy spot and its multi-passing through the high gradient zone of the relative total pressure, is proposed to clarify the originating mechanism of the unsteadiness. At the operating points near the PEP, the main flow is weaker than the TLF and the interface moves upstream. The low energy spot which propagates along in the close behind of the interface has opportunity to circulate in the circumferential direction and passes through the sensitive interfaces several times, a slight perturbation therefore may be magnified significantly and develops into the self-induced unsteadiness. The explanation is demonstrated by numerical results.