叶片难抛光区域粗糙度对压气机性能的影响∗

摘要

The influence of surface roughness in the difficult-to-polished blade regions,such as blade tip,blade fillet and hub,on the aerodynamic performance of the compressor rotor was investigated in order to define the required roughness in these regions for blade polishing.How the roughness in the above-men-tioned regions of the rotor affects pressure loss coefficient and outlet total pressure on conditions of 98%choke mass flow in different design speeds was analyzed with the numerical aerodynamic calculation of ro-tor 37 based on computational fluid dynamics (CFD)tools.The results show that the rotor losses increase with the roughness in the difficult-to-vlished regions of the blade,and the outlet total pressure increases with the roughness of blade tip but decreases with the roughness of blade fillet and hub.The surface roughness value 15 μm is considered as a turning point,because it affects the aerodynamic performance more significantly when it is greater than 15 μm.The aerodynamic performance is most affected by the hub roughness.The hub roughness reduces the rotor losses at 60% of the design speed,but increases the rotorlosses at 80%,100% of the design speed.%研究压气机转子中叶片叶顶、叶根倒圆、下端壁这类难以自动抛光区域的表面粗糙度对转子气动性能的影响规律，旨在为叶片抛光加工表面粗糙度目标的制定提供指导。基于计算流体动力学(CFD)对跨音速转子 rotor37进行气动计算，分析了98%阻塞流量工况不同转速下各部位表面粗糙度对转子的损失系数和出口总压的影响规律。结果表明，在设计转速下，叶片各部位的表面粗糙度增加均使转子损失增加，叶顶的表面粗糙度使出口总压升高，而叶根倒圆和下端壁表面粗糙度使出口总压降低；表面粗糙度15μm 是一个转折点，大于15μm 时表面粗糙度对气动性能的影响程度开始变大；下端壁表面粗糙度对性能的影响最大，在60%设计转速下，下端壁表面粗糙度使损失降低，但是在80%和100%设计转速下，则使损失增加。