Adaptive Mesh Refinement: Quantitative Computation of a Rising Bubble using COMSOL Multiphysics®

To accurately measure the variation of the unknowns, a relevant mesh should have a high density of degrees of freedom in regions where the norm of the gradient of the quantity of interest is significant. Fine meshes, on the other hand tend to induce long computational times, especially when complex 3D physics (fluid mechanics, electromagnetism …) are involved.  The Adaptive Mesh Refinement (AMR) method implemented in COMSOL Multiphysics® can help to mitigate computational time while maintaining precision. Instead of using a fixed mesh throughout the simulation, the initial mesh is adapted to the solution while the simulation is computed.

In this paper, the rising of a gas bubble in a liquid is modelled with the finite element (FE) software COMSOL Multiphysics® using a two-phase flow approach. Results from literature are compared with results obtained using both fixed and adaptive meshes. The results from the AMR method available in COMSOL Multiphysics® are then compared with results obtained with different software: NaSt3D and OpenFOAM.