离心压气机无叶扩压段流场的建模仿真与优化设计

Centrifugal Compressor Optimization Design and Flow Field Modeling Simulation

摘要: 研究无叶扩压段对压气机性能的影响，从而得到离心压气机设计点处性能变化的规律。首先，利用Vista CCD软件建立叶轮模型，再用Bladegen建立有叶扩压器的模型，然后与不同长度的无叶扩压段配合，利用CFX软件对其进行数值分析，发现一定限度内无叶扩压段越长，则压气机扩压能力越好。改变无叶扩压段机匣形状，设计了缩放型无叶扩压段，并且利用CFX对不同缩放程度的无叶扩压段进行仿真对比分析，结果表明收缩型的无叶扩压段对叶轮出口处分离涡的形成有抑制作用，无叶扩压段中段高度h为4.7 mm时，缩放型的无叶扩压段性能最优。

Abstract: In order to study the effect of the vaneless diffuser on the performance of the compressor, the im-peller and diffuser models of the same centrifugal compressor were first matched to different lengths of the vaneless diffuser, and then the impeller and diffuser models are matched with the same length and different shape of the vaneless diffuser sections. First, using the Vista CCD software to establish the impeller model, and then using Bladegen to establish a vaned diffuser, and then with different lengths of vaneless diffuser section, using CFX software for numerical analysis, it was found that the longer the leafless diffuser section, the better the compressor’s capacity for pressure expansion. The vaneless diffuser section is changed in shape, and the leafless diffuser section is designed to shrink first and then expand. The CFX is used to simulate and compare the vaneless diffuser sections with different scales. The results show that this leafless diffuser section has an inhibitory effect on the formation of the separation vortex at the impeller exit. When the height of the middle section of the non-leaf diffuser section is 4.7 mm, the scaled leafless diffuser section has the best performance.