Effect of Winglet Geometry Arrangement and Incidence on Tip Clearance Control in a Compressor Cascade

• Published in: Journal of thermal science Vol. 23; no. 4; pp. 381 - 390
• Main Authors: Han, Shaobing, Zhong, Jingjun, Lu, Huawei, Kan, Xiaoxu, Yang, Ling
• Format: Journal Article
• Language: English
• Published: Heidelberg Science Press 01.08.2014
• Subjects: Classical and Continuum Physics; Engineering Fluid Dynamics; Engineering Thermodynamics; Heat and Mass Transfer; Physics; Physics and Astronomy; 几何布置; 压力损失系数; 压气机叶栅; 发病率; 叶尖泄漏涡; 翼梢小翼; 间隙控制; 非设计条件; tip clearance flow; compressor cascade; incidence; blade tip winglet
• ISSN: 1003-2169; 1993-033X
• DOI: 10.1007/s11630-014-0721-7

An experimental study is conducted to investigate the influences of blade tip winglet on the flow field of a compressor cascade. The tests are performed in a low speed linear cascade with stationary endwall, with three blade tip configurations, including the baseline tip, the suction-side winglet tip and the pressure-side winglet tip. The fiowfield downstream of the cascade is measured using five-hole probe, from which the three-dimensional velocity field, vorticity field and pressure field are obtained. Static pressure measurements are made on the endwall above the blade row using pressure taps embedded in the plywood endwall. All measurements are made at both design and off-design conditions for tip clearance level of about 2 percent of the blade chord. The results revealed the incidence variation significantly affects the secondary flow and the associated loss field downstream of the cascade, where the tip leakage vortex and passage vortex exist as the major contributors on the field. The winglet geometry arrangements can change the trajectory of the tip leakage vortex. The suction-side winglet tip blade provides a lower overall total pressure loss coefficient when compared to the baseline tip blade and pressure-side winglet tip blade at all incidence angles.