某小型风扇内进口总压畸变引起流动损失分析

采用数值模拟方法对方波形式的进口总压畸变对风扇流场的影响进行了全三维非定常数值模拟.详细分析了畸变造成的动静叶栅流道内部流动损失的形式和原因.分析表明,动静叶流道内的损失在畸变和非畸变区域向下游疏运的方式不同.在动叶根部和中径区域流动损失的主要形式是疏运损失和掺混损失.畸变会使多种损失相叠加.在静叶中,畸变会在中径以下区域造成大范围的漩涡,造成回流,从而使损失增加.

Analysis of flow loss induced by inlet total pressure distortion in a small fan

Numerical simulation of the unsteady flow field in a small fan using time-accurate three-dimensional Navier-Stokes solver was carried out.The numerical simulation focused on a small fan with inlet square wave total pressure distortion.The pattern and causation of flow loss caused by the pressure distortion in rotor and stator were analyzed.It is found that the influence of distortion is different at different radial positions.In the hub area,transportation-loss and mixing-loss are the main loss patterns.Distortion not only complicates them but also strengthens them.Especially in stator,inlet total pressure distortion induces large-scale vortex,which causes backflow and increases the loss.Finally,the details of flow loss both distorted and non-distorted flow fields are described and analyzed.