低温液体流动沸腾数值计算中的动量模拟

采用双流体模型计算了液氮在垂直管内的过冷流动沸腾过程,着重考察了相间动量传输模型对数值预测结果准确性的影响。研究表明,相间非曳力,尤其是壁面润湿力对于数值预测的准确性有着决定性的作用。此外,正确地估计沸腾系统中气泡的平均直径对于两相流传输特性的准确预测也有着十分重要的作用。

Modelling of Momentum Transport in Numerical Simulation of Flow Boiling of Cryogenic Liquids

Flow boiling of subcooled liquid nitrogen in a vertical tube was numerically simulated using the two-fluid model of two-phase flows. Special attention was paid to the term of inter-phase momentum transfer in the two-fluid model. It was shown that the non-drag forces, especially the wall lubrication force, play an important role in an accurate prediction of the transport of mass, momentum and energy between the phases. Also, accurate assess of the mean bubble diameter is necessary to a precise numerical prediction.