[JM27]

Hi everyone,

This is my first time posting here and I am hoping some of the more-experienced users can help. I have some basic experience in Fluent but relatively new to STAR-CCM+.

I want to simulate single bubble collapse close to a wall boundary in STAR-CCM+ using VOF. To this, I am using the Eulerian multiphase model and implicit unsteady for time discretization. The flow is laminar and in my simulations I also account for the effect of surface tension between the bubble and the surrounding liquid through the phase interaction.

I initialise the gas-filled bubble of specific size at a certain position within a liquid domain by using a field function. This method is based on that shown in the STAR-CCM+ tutorial: Bubble formation in a fluidized bed. Unlike the tutorial, I do not want to model bubble formation but rather the collapse of a bubble which has already been initialised in the domain.

So far, I am using a trimmed mesh with volumetric controls for mesh refinement in the bubble region. Now, the problem with this mesh is that it is static, and in order to be able to capture bubble collapse the mesh must be moving so that it can follow the interface of the bubble and jet formation.

To start with, I have looked at the mesh provided in the bubble formation tutorial, but this is a quite generic static mesh with no such refinement and only suitable for tutorial purposes. I have looked through the STAR-CCM+ user guide and meshing tutorials several times and I am still confused as to how I can do this.
I have been through the tutorials on overset meshing but this technique requires more than region whereas I only have one in my simulation. I have also been through the DFBI tutorial, but from what I understand this is only suitable for rigid bodies (for example to model propeller rotation with respect to a hull) whereas in my case the interface of the bubble deforms due to compressibility. (In my simulations, I am modelling the gas phase within the bubble using the ideal gas law and the liquid as incompressible).

Any ideas on how this can be done ? Any tutorials which you think might be helpful in my case are also appreciated. I have been trying to find some literature on this because I think it have been done before but so far I have not come across anyone that has modelled something similar in STAR-CCM+.

Thanks in advance for your time.

[YeLingLang]

Overlapping meshes may be a good solution

[YeLingLang]

Adaptive overset mesh

[Aeronautics El. K.]

So, you need a CFD method capable of tracking the interface between 2 fluids?