论文部分内容阅读
用数值计算方法对水平传热管外过冷水垂下液膜的强制对流显热换热特性进行了研究．计算采用层流流动模型，将液膜流动区分为管顶部的滞止区和侧部的自由绕流区分别计算．滞止区计算采用Ｇｏｅｒｔｌｅｒ变换方法，绕流区计算采用自由流函数变换方法．结果证明，在喷嘴尺寸固定时，换热努塞尔特数除与膜雷诺数、普朗特数有关外，与反映管径尺寸的无量纲数、阿基米德数也相关．因此，在膜雷诺数１０３～１０４和普朗特数２～７内，得到了近似拟合公式．该公式和以往的经验公式吻合，较好地预示了文中的实验结果．为实际管排式蒸发器研究提供了依据．
The forced convection sensible heat transfer characteristics of the liquid film suspended by the supercooled water outside the horizontal heat transfer tube were studied by numerical calculation method. The laminar flow model was used to calculate the liquid film flow as the stagnation zone at the top of the pipe and the free flow around the side respectively. The stagnant zone calculation using Goertler transformation method, around the flow area calculation using free flow function transformation method. The results show that the heat transfer Nusselt number is related to the Reynolds number and the Prandtl number, and the Dimensionless number and the Archimedes number which reflect the size of the pipe when the nozzle size is fixed. Therefore, in the film Reynolds number 103 ~ 104 and Prandtl number 2 ~ 7, the approximate fitting formula was obtained. The formula is consistent with the previous empirical formula, which better predicts the experimental results in this paper. The actual tube row evaporator provided the basis.