应用 TVD 格式求解 N-S 方程预测透平叶栅二次流损失

NUMERICAL PREDICTION OF SECONDARY FLOW LOSS IN A TURBINE CASCADE BY USING TVD SCHEME TO SOLVE N-S EQUATIONS

应用ＴＶＤ格式和Ｂａｌｄｗｉｎ－Ｌｏｍａｘ代数紊流模型求解三维Ｎ－Ｓ方程，详细模拟出了一个直列透平叶栅中二次流及其损失在叶栅通道中的产生和发展过程，并给出了叶栅损失的分布状况，其结果深刻揭示了透平叶栅二次流损失的产生发展机制。本文计算得到的叶栅损失的栅距平均值沿叶高的分布曲线与实验值吻合良好，表明格式求解精度较高。

Harten's TVD scheme and Baldwin-Lomax turbulence model are applied to solving 3D N-S Equations for simulation of emergence and development of secondary flow and its loss in a rectilinear turbine cascade at a-8° incidence.The computation simulates successfully the vortex structure of the secondary flow and its loss distribution in the cascade passage.The predicted pitch averaged cascade distribution along blade height is consistent with the experimental data well.The mechanism of secondary flow loss emergence and development is revealed.It is found out that the incoming endwall boundary layer,the horse shoe vortex and its induced separation,and the shear motion of the horse shoe vortex with that of passage vortex are the major sources of the loss production,and the cascade boundary layer development and the passage vortex play an important role in the cascade loss development and redistribution.As a result,the numerical technique developed by the authors has a high accuracy and resolution,and can be adopted in the engineering application.