Detailed 3D modelling of mass transfer processes in two phase flows with dynamic interfaces

In this work a model is presented which allows us to a priori compute mass transfer coefficients for bubbles (droplets) rising in quiescent Newtonian fluids. Our model is based on the front tracking technique and explicitly accounts for the bubble-liquid mass transfer process. The dissolved species concentration in the liquid phase is computed from a species conservation equation while the value of the concentration at the interface is imposed via an immersed boundary technique. In the present study, simulations are carried out to demonstrate the capabilities of the model to predict bubble shape, flow field as well as transport of species from bubbles to the liquid phase for a group of twelve bubbles. It is found that bubbles rising in the wake of other bubbles will experience an increase of rise velocity, while the mass transfer rate is decreased