叶片厚度分布对流道式叶片性能的影响分析

Influence of blade thickness distribution on performance of runner blade

基于三维可压缩流体N-S方程和Spalart-Allmaras湍流模型,对多级离心压缩机中间级进行数值计算,研究了不同叶片厚度分布规律对流道式叶片性能的影响。通过分析不同模型级设计工况和变工况的特性及压力场、速度场分布,获得流道式叶片效率和损失分布的变化规律。结果表明:0.6倍厚度(即9.00 mm)的叶片有最高的级效率82.82%和最大压比1.483,同原有叶片厚度的模型级相比较,整级效率增加1.46%。流道式叶片厚度的变化对压缩机稳定工况的范围影响不大。从近喘工况到堵塞工况,薄叶片在总体性能上优于厚叶片。在近喘工况下,旋涡区分布于叶片进口吸力面;近堵工况下,旋涡区分布于叶片压力面。

Based on the three-dimensional compressible fluid N-S equation and Spalart-Allmaras turbulence model,the numerical calculation of the intermediate stage of multi-stage centrifugal compressor was carried out.The influence of different blade thickness distribution on the performance of the runner blade was studied.By analyzing the characteristics of different model gradel design conditions and variable working conditions,the pressure field and the velocity field distribution,the variation law of the efficiency and loss distribution of the runner blade was obtained.The results show that the blade with 0.6 times thickness(i.e.9 mm)has the highest grade efficiency of 82.82%and the maximum pressure ratio of 1.483.Compared with the model grade of the original blade thickness,the whole stage efficiency increases by 1.46%.The change of blade thickness has little effect on range of stable working conditions of compressor.From near surge condition to blockage condition,the overall performance of thin blade is better than that of thick blade.The vortex region is distributed on the inlet suction surface of the blade under the condition of near surge,and on the pressure surface of the blade under the condition of blockage.