叶片表面粗糙度对压气机叶栅内三维角区分离及损失研究

The compressor blade surface roughness is easily deteriorated by deposits of ash and sand, as well as corrosion at wet environment, which results in the failure of aerodynamic behavior for compressor failed. Meanwhile, the three-dimensional (3D) separation near the hub causes large performance loss for compressor. Thus, a low-Reynolds compressor cascade was studied to investigate that whether the roughness on the blade can promote the 3D separation and make a difference on all type of the loss in the cascade or not by CFX. In this study, the Gamma transition model was introduced to investigate the influence of blade surface roughness to transition phenomenon. It can be concluded that the blade surface roughness has more effect on the separation transition and the bypass transition than the reverse transition. Furthermore, a detailed loss sources analysis model was used to study the loss influenced by the surface roughness, which divided the total loss in the cascade into the leading edge loss, the surface friction loss, the secondary flow loss and the wake flow loss. The results show that the total loss increases to 9.6% at large scale of corner separation condition when the equivalent sand grain roughness in the blades increases to 50μm. And the leading edge loss is most sensitive to the surface roughness. With the help of the topology analysis method, it can be found that the movement of the separation bubble is the most obvious phenomenon in the field as the roughness increasing.