关于叶片前缘加工缺陷及气动合格性的探讨

Discussion on Machining Defects of Blade Leading Edge and Aerodynamic Qualification

为了指导压气机叶片前缘的精细化加工,以某高亚声速压气机叶型为研究对象,基于叶片前缘的实际加工过程,建立“过切前缘”与“欠抛前缘”2类典型加工缺陷模型,并采用数值模拟方法研究了不同形式、不同大小、不同位置的前缘缺陷对气动合格性的影响。研究结果表明:前缘过切角度是影响叶片气动合格性的重要因素。随着过切角度的减小,叶片的气动不合格性逐渐增大。不同位置的前缘缺陷对叶片气动合格性的影响与来流攻角有关。叶片前缘双侧加工缺陷对气动合格性的影响要高于单侧前缘加工缺陷。对于“过切”和“欠抛”前缘缺陷,均存在前缘实际轮廓满足加工公差要求,但叶片气动合格性不满足设计期望的情况。所获得的前缘加工缺陷影响规律可用于指导前缘精细化加工以及制定叶片前缘质量评判标准。

In order to guide the fine machining of the leading edge of compressor blades,a high subsonic compressor blade was taken as the research object.Based on the actual machining process of the leading edge,two typical machining defect models of over cutting and under polishing leading edge were established.The effects of machining defects of leading edges with different forms,sizes and positions on aerodynamic qualification were studied by numerical simulations.The results show that the over cutting angle is an important factor affecting the aerodynamic qualification of the blade.With the decrease of over cutting angle,the aerodynamic disqualification of blade gradually increases.The impacts of leading edge defects with different positions on aerodynamic qualification are related to incoming incidence.The influence of bilateral machining defects of leading edges on aerodynamic qualification is higher than that of unilateral machining defects.For over cutting and under polishing machining defects,the actual leading edge meets the machining tolerance requirements,but the aerodynamic qualification may not meet the design expectations.The results of machining defects of leading edge can be used to guide the fine machining of leading edge and establish the quality evaluation standard.