向心透平蜗壳轴向对称性影响的数值模拟研究

基于三维Naiver-Stokes方程组，采用分块结构化网格，用数值计算的方法模拟了矩形截面轴向对称和非对称蜗壳内气体的流动．湍流模型采用Baldwin—Lomax代数模型．模拟的结果表明，对称蜗壳和非对称蜗壳在出口气流特征上基本一致，非对称蜗壳气流的周向均匀性要优于对称蜗壳；非对称涡壳的后1／4流程出现了横向压力梯度，这个梯度容易引起二次流动损失．

Investigation of the effect of section axisymmetry in a radial inflow turbine scroll

The flow in symmetrical and nonsymmetrical rectangular section scroll is studied by numerical simulation method based on 3-D N-S equation and structured multi-grid.Baldwin-Lomax model is adopted for turbulence enclosure.Results show that: flow features at the scroll outlet are fundamentally similar for axisymmetric and non-axisymmetric configuration.Peripheral uniformity in non- axisymmetric scroll is somewbat better than that in axisymmetric one.in non-axisymmetric scroll pressure gradients appear on the cross sections in the later 1/4 flow channel,which are responsible for the secondary flow losses.