可变液膜厚度下垂直塞状流参数预测模型

基于流动机理的分析建立了塞状流参数预测模型;模型中考虑了液膜的厚度变化.分析了液膜厚度变化对预测结果产生的影响,并用公开发表的数据对模型进行了验证.分析表明,若忽略液膜厚度的变化,将Taylor泡简化为圆柱体,会使其长度的预测值偏小,导致压力梯度的预测出现正偏差,且偏差会随气相表观速度的增加而增大.新建模型反映了液膜的流动特性,可对不同来源的数据进行较为准确的预测.

Hydrodynamic Model of Slug Flow in Vertical Pipes Considering Variable Thickness of Liquid Film

Based on analysis of flow mechanism, a hydrodynamic model of slug flow in vertical pipes was developed considering the variable thickness of liquid film. Effects of film thickness on results were discussed and the model was evaluated with experimental data available from the literature. It was found that if the variation of thickness was neglected, and Taylor bubble was considered as a cylindrical bubble, the length of Taylor bubble would be under predicted. The simplification can also result in an over prediction of pressure gradient, and the deviation will increase as gas superficial velocity increases for a fixed liquid superficial velocity. The improved model takes into account the flow characteristic of liquid film, and can predict the data obtained from different sources with a fairly well accuracy.