[markhi]

Dear COMSOL Community,

I hope this message finds you well. I am simulating the shrinking of gas bubbles in a stationary liquid due to gas diffusion from the bubble into the surrounding liquid.

I am employing the Moving Mesh (ALE) model alongside the Transport of Diluted Species (tds) model for this simulation. The simulation setup is a spherical bubble (with initial gas concentration, surface tension, and diffusion coefficient) in the middle of liquid ( with zero gas concentration and fixed temperature and pressure).

Despite setting up the models, I have encountered a significant issue: the moving mesh model does not update the bubble size over time, even though the gas concentration inside the bubble changes as expected. This suggests that while the gas is diffusing out of the bubble, the mesh is not reflecting the corresponding shrinkage of the bubble.

I have successfully observed mesh deformation and bubble size changes when coupling the moving mesh model with other models, such as laminar flow or heat transfer. This issue seems specific to the coupling between the moving mesh model and the Transport of Diluted Species model.

I have reviewed the COMSOL documentation and relevant forum posts, but this specific issue with the moving mesh model not updating the bubble size persists. Any insights, examples, or detailed guidance would be beneficial.

Thank you in advance for your help.