Taylor bubble migration velocity prediction model based on energy conservation under countercurrent condition

Key words:  countercurrent flow  Taylor bubble  speed prediction model  velocity field  energy conversion

Abstract:

Based on the analysis of Taylor bubble migration behavior under countercurrent condition and considering the characteristic constitutive equation of fluid, the calculation method of pipe flow field and velocity field around Taylor bubble was proposed, and the energy dissipation model of bubble resistance based on the velocity field model was established. On the bases of the energy conservation analysis, a unified Taylor bubble rising velocity prediction model (Model T) suitable for different rheological types was put forward to explore the law of Taylor bubble migration under countercurrent conditions. The results show that compared with the public experimental data, the prediction error of model T for the turning point of Taylor bubble migration velocity under countercurrent conditions is less than 7.35%. With the increase of bubble volume, the energy dissipation ratio of nose region and wake region decreases, and the energy dissipation ratio of the liquid film region increases. With the increase of bubble volume, the work proportion of yield stress, inertial force and surface tension decreases, and the proportion of viscous dissipation increases. The reason for restricting the increase of bubble rising speed is that the positive work value of bubble buoyancy is offset by the increased energy dissipation in the liquid film area.