Investigation of non-uniform leading-edge tubercles in compressor cascade:Based on multi-objective optimization and data mining  

作　　者：Jiezhong DONG Wuli CHU Haoguang ZHANG Bo LUO Tianyuan JI Ziyun ZHANG 

机构地区：[1]School of Power and Energy,Northwestern Polytechnical University,Xi’an 710129,China

出　　处：《Chinese Journal of Aeronautics》2024年第7期134-152,共19页中国航空学报（英文版）

基　　金：support by the National Natural Science Foundation of China(No.52076179).

摘　　要：Corner stall receives noticeable attention in the aeroengine field as an important phenomenon in highly-load compressors.Non-uniform leading-edge tubercles,as an effective method to delay stall,are introduced into the compressor.In this paper,the shape of leading-edge tubercles was controlled by a third-order Fourier function.To judge corner stall,a more precise stall indicator for compressor cascade with flow control methods was defined.Besides,the total kinetic energy of the secondary flow at large incidence was adopted as a parameter for stall evaluation to save computing resources.The results of multiobjective optimization reveal that the loss coefficient exhibited negligible variation at design incidence,while the total kinetic energy of secondary flow showed a significant reduction at large incidence,resulting in a substantial increase in stall incidence.In the optimal profiling cases,the stall incidencewas delayed from 7.9°to 11.6°.The major purpose of the research is to provide proper design guidelines for nonuniformleading-edge tubercles and uncover the flow controlmechanisms of leading-edge profiling.Hence,the geometric features that meet different optimization objectives were extracted through geometric analysis near the Pareto Front and through Self-OrganizingMap(SOM)dataminingmethods in the optimization database.Besides,flow field analysis reveals the flow control mechanism of leading-edge tubercles.The convex-concave-convex structure at the 0%-70%blade height region can form two branches of leading-edge vortex pairs that are opposite in the rotation direction to the passage vortex.The two branches of leading-edge vortex pairs mixed with the leading-edge separation vortex to form two stronger mixed vortices,which can effectively suppress the development of passage vortex and delay stall incidence.

关 键 词：Corner stall Non-uniform leading-edge tubercles Stall indicator Stall evaluation parameter Mixed vortex 

分 类 号：V233[航空宇航科学与技术—航空宇航推进理论与工程]