Simulation of precipitation/dissolution phenomena with large phase volume change using single-field C-CST model

This study presents a numerical approach for modelling diffusion-driven mass transfer in incompressible two-phase systems. We implemented the Compressive Continuous Species Transfer single-field formulation, utilising a Volume-of-Fluid approach with the CICSAM compressive scheme. While existing single-field methodologies successfully model dissolution phenomena, our investigation reveals that state-of-the-art discretisation approaches are inadequate for accurately modelling precipitation. Consequently, we introduced a shifted discretisation methodology, inspired by two-field formulation, for source terms involving mass transfer rate. This shifted method enables simulation of both dissolution and precipitation phenomena within the single-field framework. The approach is validated against analytical solutions across various dimensional scenarios, including novel theoretical solutions for 1D and 2D precipitation cases derived from existing 3D theoretical solutions. Finally, we demonstrate the method effectiveness by examining gas bubble mass transfer in creeping flow, comparing results with semi-analytical solutions and identifying limitations under high Péclet number conditions.