叶顶间隙对跨音速离心压气机气动性能影响分析

基于控制变量法对某跨音速离心压气机进行数值模拟,研究了叶轮尾缘叶间隙改变对其气动性能的影响。仅改变该离心叶轮的尾缘叶顶间隙,在设计转速下进行全三维黏性数值模拟,对相关气动参数进行分析。计算结果表明,相较于小流量工况,尾缘叶顶间隙的改变对离心压气机大流量工况的气动性能影响更大;在设计流量下,离心叶轮的压比、效率与叶轮尾缘出口间隙大小之间具有一定的线性关系,随着叶尖间隙增大,叶轮叶尖泄漏流的强度明显增强,导致叶轮的增压能力下降。

Analysis of The Influence of Tip Clearance on Aerodynamic Performanceof Transonic Centrifugal Compressor

Based on the control variable method,a transonic centrifugal compressor was numerically simulated.Only the tip clearance of the trailing edge of the centrifugal impeller was changed,and the full three-dimensional viscosity numerical simulation was carried out at the design speed to analyze the relevant aerodynamic parameters.The results show that the aerodynamic performance of the centrifugal compressor under high flow condition is greatly affected by the tip clearance of the trailing edge,compared with small flow condition;At the design flow rate,there is a strong linear relationship between the pressure ratio and efficiency of the centrifugal impeller and the size of the outlet clearance at the trailing edge of the impeller,as the tip clearance increases,the strength of the tip leakage flow of the impeller increases significantly,leading to a decline in the impeller's supercharging ability.