Abstract

The flow and heat transfer characteristics of gas-liquid Taylor flows in a horizontal tube with 3.12 mm inner diameter were studied numerically with the volume of fluid method. The bubbles are patched using the user defined functions based on the experimental volumes and formation frequencies. Numerical results agree well with the experimental results and empirical correlations. The results indicate that the gravity plays an important role in the Taylor flow in mini tubes. The bubble shape is asymmetric and the normalized film thickness is larger at the tube bottom. The wall shear stress in the liquid region remains approximately unchanged, while there is a sharp increase near the tail and nose of bubbles. The pressure distribution is divided into four parts, and the presence of air increases the pressure gradient. The internal recirculation in the liquid slug can enhances the heat transfer coefficients.

摘要

用流体体积法数值研究了内径为3.12 mm的水平管中气液泰勒流的流动和传热特性。根据实验体积和形成频率，使用用户定义的函数修补气泡。数值结果与实验结果和经验相关性非常吻合。结果表明重力在微型管中的泰勒流中起重要作用。气泡形状不对称，管底归一化膜厚较大。液体区域的壁面剪应力基本保持不变，而气泡尾部和鼻子附近则急剧增加。压力分布分为四个部分，空气的存在增加了压力梯度。