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为揭示流场中粘性引起的边界层分离与自发凝结相互作用的机理,对缩放喷管和汽轮机叶栅中的自发凝结两相流动进行了数值模拟.气相采用N-S方程,液相凝结过程采用对多阶复合参数进行积分的方法求解.通过比较粘性流动和非粘性流动中液相参数分布的差异,分析了边界层分离和尾迹涡扰动与凝结相互作用的机理.结果表明:凝结的存在使得湿蒸汽流动中叶栅吸力面边界层的分离程度远大于过热蒸汽流动中的分离程度,边界层分离产生的损失不可忽视.对边界层分离和尾迹涡产生叶型损失的原因进行了分析,结果表明:尾迹涡的扰动作用使得成核过程发生了变化,且改变了水滴数和湿度的分布.
In order to reveal the mechanism of interaction between boundary layer separation and spontaneous condensation caused by viscous flow in flow field, the numerical simulation of spontaneous condensed two-phase flow in scaled nozzle and steam turbine cascade is carried out. The NS equation is adopted for the gas phase, The multi-order complex parameters are solved by integral method.The mechanism of interaction between boundary layer separation and wake vortex perturbation and coagulation is analyzed by comparing the difference of liquid phase parameter distribution in viscous flow and non-viscous flow.The results show that the existence of coagulation makes wet The separation of the boundary layer of the suction surface of the cascade in the steam flow is much greater than that of the superheated steam flow, and the loss caused by the boundary layer separation can not be neglected. The reasons for the loss of the boundary layer separation and wake vortex generation are analyzed. The wake vortex perturbation causes the nucleation process to change, and changes the distribution of water droplet number and humidity.