Understanding of tip clearance flow structure in high speed mixed flow compressor

作     者：Hemant Kumar Chetan S.Mistry 

作者机构：Department of Aerospace EngineeringIndian Institute of TechnologyKharagpurWest Bengal 721302India 

出 版 物：《Propulsion and Power Research》 (推进与动力（英文）)

年 卷 期：2023年第12卷第3期

页      面：356-379页

核心收录：

学科分类：080704[工学-流体机械及工程] 080103[工学-流体力学] 08[工学] 0807[工学-动力工程及工程热物理] 0802[工学-机械工程] 0825[工学-航空宇航科学与技术] 0801[工学-力学（可授工学、理学学位）] 

主　　题：Recirculation zone Vortex breakdown Tip leakage flow Mixed-flow compressor Jet-wake flow Vaned-diffuser 

摘      要：This paper addresses the necessity to make a physical interpretation of a highly complex three-dimensional tip clearance flow field study for high-speed mixed-flow compressor having stage exit static pressure to inlet total pressure ratio of 3.8 with 39,836 rpm rotor *** four different tip configurations namely the constant(l Z 0.016 and 0.019)and variable(l Z 0.011(inlet)-0.019(exit)and 0.019(inlet)-0.022(exit))tip clearances were numerically analysed using available experimental *** numerical investigation reveals that in contrast to the classic jet-wake pattern,two anomalous velocity profiles formed at the impeller exit which results in pressure losses in the vaneless *** the impeller inlet,the tip leakage flow rolls up to discrete tip leakage vortex structure for each tip clearance *** results in the formation of a region of momentum deficit,recirculation zone,which gets weakened as it moves *** tip clearance configuration is observed to profoundly influence the extent and vorticity of the tip leakage *** the splitter blade passage,the tip leakage flow and Coriolis flow interact with passage flow,resulting in the formation of two secondary passage vortices that move downstream along the pressure and suction surface of the splitter *** tip clearance configuration directly influences the impeller exit jetwake pattern by modulating the secondary passage vortices trajectory and ***,off-design analysis for tip clearances l Z 0.016 and l Z 0.019,depict distinctive tip leakage vortex *** operating near the stall conditions(80%of design mass flow rate),l Z 0.019 exhibits bubble shape tip leakage vortex breakdown occurring near the impeller *** result in a substantial change in the tip leakage vortex nature;expansion of the recirculation zone and early weakening of the vorticity in the tip leakage *** is observed that vortex breakdown plays a vital role in characte