粗糙度对边界层流动及压气机气动性能的影响

摘要

为了研究叶片表面粗糙度对边界层流动及压气机气动性能的影响,本文以T3系列平板转捩实验为对象,通过构建Gauss型粗糙表面来验证等效砂粒模型计算方法的适用性,并采用商业软件ANSYS CFX对NASA Stage35型压气机进行了表面粗糙度的数值模拟研究.研究结果表明:采用等效砂粒模型进行表面粗糙度的数值研究能够满足工程要求;当动叶表面粗糙度ks由1 μm增大至100 μm时,压气机峰值效率减小3.5%,对应工况点的压比减小0.8%,总温比升高0.4%.同时,粗糙度增加后的压气机最大压比与光滑情况下相比减小4.5%;计算得到了总损失系数ω和效率损失系数ζ与叶片表面粗糙度的关系,具有一定的工程价值.%To study the degradation mechanism of a compressor caused by surface roughness,numerical research was conducted on the surface roughness on boundary-layer flow and characteristics of an axial compressor using commercial software.Herein,the applicability of the equivalent sand model method was verified through the construction of a Gauss roughness surface on a T3 plate.Then,numerical research of the surface roughness on the characteristics of the axial compressor was performed using commercial software ANSYS CFX.The numerical results indicated that the equivalent sand model was accurate enough for roughness research in practical engineering.When blade surface roughness increased from 1 μm to 100 μm,the peak efficiency of the compressor decreased by 3.5%,the pressure ratio at the corresponding point decreased by 0.8%,and the total temperature ratio increased by 0.4%.At the same time,the maximum pressure ratio decreased 4.5% when compared to the decrease in maximum pressure ratio of the smooth case.The relationship of surface roughness to the total pressure loss coefficient ω and the efficiency loss coefficient ζ was obtained.