气泡在静水中上升破裂产生射流特性的数值模拟

Numerical simulation of bubbles rising and bursting under buoyancy effect in static water

为了研究不同直径参数对气泡上升、破裂及产生射流的影响,建立了二维旋转数学模型,选用SIMPLEC算法进行数值计算,对单个气泡在静水中运动进行了数值模拟.采用VOF界面几何重构方案,追踪气泡运动过程中气泡表面的变化,并监测气泡上升速度随时间的变化特性.探讨了气泡在抵达自由液面时的破裂机理以及气泡破裂时产生射流的特性.结果表明:气泡在上升过程中逐步由球形变为椭球状,在到达液面时破裂,并产生射流,随着气泡直径的增加,气泡上升速度逐渐增大,气泡破裂时喷射的射流也越高.

In order to investigate the effects of bubble diameters on bubbles rising,bursting and jetting,the two-dimension rotating mathematical model was established.The SIMPLEC algorithm was used to simulate a single bubble motion characteristic in static water.The VOF interface geometric reconstruction scheme was adopted to track the bubble surface change and monitor the rising bubble speed change characteristic.The characteristics of bubble in the free surface burst and the jet generate mechanism were discussed.The results show that the rising bubbles gradually become ellipsoid from spherical form during the rising process.When the bubble reaches to water surface,it bursts to generate jet.The rising velocity of bubbles are gradually increased with the increasing of bubble diameters,and the jet is sprayed higher when bubbles burst.