摘要
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．
Forced convective sensible heat transfer of subcooled falling water on the horizontal heated tube is studied by using numerical calculation and experiment to investigate the effects of flow conditions and tube diameter.The numerical analysis show that Nusselt number is governed by the three variables:film Reynolds number,Prantal number and Archimedes number.The calculation adopts a laminar flow model and divides the film flow zone into two calculating zones.One is the flow stagnation zone in which the Goertler change method is used,the other is the free film flow zone in which the free flow boundary conditions are changed to the mixed boundry conditions.By the numerical analytical results,a simple theoretical equation is proposed and it agrees well with the experimental data and experimental correlations presented by other researchers.
出处
《上海交通大学学报》
EI
CAS
CSCD
北大核心
1998年第7期70-74,共5页
Journal of Shanghai Jiaotong University
