对流梯形微通道内气液两相流动的数值研究

Numerical simulation of gas-liquid two-phase flow in a convection T-junction microchannels

采用VOF方法,对梯形微通道内不可压缩气液两相流动进行了数值模拟研究,详细分析了气泡形成过程,以及当量直径、截面形状、液体表面张力和粘度等对气泡液柱形成过程和长度的影响,拟合出微通道气泡液柱长度计算公式。结果表明:气泡液柱的长度受表观气速和表观液速的影响较大;表面张力对气泡尺寸的影响较小,当液体粘度增加为水粘度的10倍时,形成的气泡形状不规则。增大表面张力,形成气泡的时间增加;增大粘度,形成气泡的时间减小。

The numerical simulation was performed to investigate the incompressible gas -liquid flow in a T -junction with the method of VOF. The formation process of bubble was influenced by difference factors, such as hydraulic diameter, the shape of section, superficial velocity, surface tension and liquid viscosity. The formula calculating the length of bubble and liquid column was obtained. The numerical results show that both the hydraulic diameter and superficial velocity play an important role in the size of bubble, and the effect of surface tension is relatively small. At the same time, when the liquid viscosity is ten times larger than water, the bubble is not regular in shape. While the time of bubble formation increases when surface tension increase, and reduces when viscosity increase.