正倾斜叶片压气机叶栅二次流的数值研究

应用Beam-Warming近似隐式因子分解格式以及MML代数湍流模型,采用拟压缩性方法求解雷诺平均拟压缩N－S方程组,对正倾斜叶片压气机叶栅内三维粘性流场进行了数值研究,并与直叶栅进行了对照。结果发现,正倾斜叶栅中上、下通道涡的发生、发展过程与直叶栅存在明显的差异,这导致正倾斜侧二次流减弱,负倾斜侧二次流高损失区扩大,流动状况恶化,叶栅顶部区域的附面层分离发展成一个向叶栅中部扩展的更大的区域。计算与实验结果比较,两者吻合较好。

Numerical Investigation of Secondary Flows in a Compressor Cascade with Positively leaned Blades

With the help of Beam-Warming's approximate and implicit factorization scheme and a MML algebraic turbulence model and by using the method of quasi-compressibility for the solution of a Reynolds-average quasi-compressibility N-S equation a numerical investigation was performed of the three-dimensional viscid flow field of a compressor cascade with positively leaned blades. The results of the investigation were compared with those of a linear cascade. It has been found that the generation and development process of the upper and lower channel vortex of the positively leaned cascade is distinctly different from that of the linear cascade. This has led to a weakening of the secondary flow at the positively leaned side, an expansion of the secondary-flow high loss zone at the negatively leaned side and a deterioration of the flow conditions. The separation of the boundary layer at the cascade top region has developed into a greater zone expanding to the cascade middle portion. The calculated results agree relatively well with the experimental ones.