孔口出流气泡运动特性数值模拟

为了研究连续供气条件下,气泡运动特性与孔口进气速度、孔口直径的关系,对孔口出流气泡在静水中上升运动过程进行了研究,采用OpenFoam开源程序计算得到的静水中气泡上升运动模拟结果与试验结果吻合较好。通过改变孔口进气速度、孔口直径,分析了气泡的脱离时间和脱离直径,对比了初始球型气泡与孔口出流气泡的上升运动差异,提出可将相对速度B用于描述初始气泡终速度与孔口进气速度的关系,并采用不同无量纲参数对气泡运动相对速度进行了预测。结果表明:We数及Re数对气泡运动相对速度B的预测效果较好,气泡初始状态对气泡运动轨迹影响较大。研究成果进一步丰富了气泡运动相关领域的成果,为下一步精细刻画气泡复杂运动开创了思路。

Numerical Simulation of Bubble Characteristics of Outlet Bubbles in Orifices

In order to study the relationship between bubble motion characteristics and orifice gas inflow velocity or hole diameter under continuous gas supply conditions, we investigated the movement of the outlet bubbles in a still water. The bubble rise motion in still water simulated by using the OpenFoam of open source program is in consistence with experimental measurements. By adjusting the orifice gas inflow velocity and the hole diameter, we examined the detachment time and the diameter of the bubble and compared the difference of upward movement between initial spherical bubble and orifice outlet bubble. We proposed to describe the relationship between initial bubble velocity and gas inflow velocity by using relative velocity B of bubble motion. By using different dimensionless parameters, we predicted the value of B. Simulation and analysis results show that the We and Re numbers accurately predict the relative velocity B of bubble motion. The initial state of the bubble has a great influence on the trajectory of the bubble. The research results have further enriched the results in the related fields of bubble motion, and created ideas for the next step to finely characterize the complex motion of bubbles.