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采用层流和紊流两种模型对水平管外垂下液膜的强制对流蒸发换热性能进行了数值计算 .计算中 ,对管顶部的冲击滞止区和管侧部的自由绕流区分别采用不同的坐标变换方法进行微分方程组简化 .根据滞止区计算结果确定自由绕流区的初始边界条件 ,排除了以前类似计算中人为假定计算边界条件的缺陷 .紊流计算采用壁面函数法 .计算结果和作者的单管和管排实验数据及其他研究的实验数据进行了比较 ,结果表明 ,实验值处于层流解和紊流解之间 ,更靠近紊流解 .实验证明 ,单管和三管管排的平均换热系数十分接近 ,数值计算结果对管排中各管都能适用
The laminar flow and turbulent flow models were used to calculate the forced convective heat transfer performance of the liquid film hanging down from the horizontal tube. In the calculation, the free flow around the impact stagnation zone and the tube side at the top of the tube were respectively Different coordinate transformation methods are used to simplify the differential equations.According to the calculation results of the stagnation zone, the initial boundary conditions of the free flow-around area are determined, and the defects of artificial assumption in the similar calculation are excluded.The turbulence calculation is based on the wall function method The results are compared with the experimental data of the single tube and the tube row of the author and experimental data of other studies. The experimental results show that the experimental values lie between the laminar and turbulent solutions and closer to the turbulent solution. The average heat transfer coefficient of the tube row is very close, the numerical calculation results can be applied to each tube in the tube row