Numerical study on thermocapillary convection in liquid bridge under surrounding shear gas stream

Ruquan Liang,Limin Kong,Fuqiang Yan,Shuo Zhang,Di Bei,G.A Chang,G Chen,S Arumuga Perumal,M Ma

doi:10.1051/matecconf/20164006001

Abstract

In this paper, a numerical simulation on the flow of liquid bridge and gas flow channel has been conducted to analyze the effect of airflow velocity on the isothermal liquid bridge free surface and the flow pattern in liquid bridge. The results show that the different pressure makes the lower part of liquid bridge shrink but makes the upper expand for the silicone oil liquid bridge of volume ratio V = 1, aspect ratio τ =1. It will cause volatility in surface when shear gas stream just acting on the free surface of liquid bridge. When the shear gas stream acting on the free surface lasts 0.14s, the fluctuation of free surface reaches a steady state, and the fluctuation of surface is less than 0.5μm. In the process of free surface wave, the maximum value of deformation usually appears in the bumps or the pits, and the deformation of the point near z = d / 2 is always zero.

Highlights

A new direction of studying floating zone method is using shear gas stream to restrain the effect of thermocapillary
The results show that the different pressure makes the lower part of liquid bridge shrink but makes the upper expand for the silicone oil liquid bridge of volume ratio V = 1, aspect ratio τ =1
The reason was that the vast majority of studies used a simplified model and didn’t take into account the deformation of liquid bridge free surface caused by shear gas stream, which set the free surface of liquid bridge to be non-deformable cylindrical or non-deformable surface by fluid volume and Young-Laplace equation[4-5], affecting the accuracy of the findings

Summary

Introduction

A new direction of studying floating zone method is using shear gas stream to restrain the effect of thermocapillary. This article aims to study the deformation of liquid bridge surface caused by shear stream and the changes of temperature filed in internal flow field, which is under normal gravity conditions. Based on the basic knowledge of two-phase flow, we investigate the effect of air stream for isothermal liquid bridges. It directly services for the melt crystal growth of float zone on the ground, aiming at improving the quality of existing materials and processes, and it will further enriches the relevant research results of thermocapillary convection and small two-phase flow

The physical model

The influence of shear airflow on isothermal liquid bridge

Conclusions