[keepfit]

Hi Foamers,

When I was calculating the surface integral of Tau (the stress tensor field) on an internal region ABCD (rectangle here) using Gauss's theorem, some significant error was found between the calculated and the analytical result.

The region ABCD (rigid solid body) is treated as fluid material m2. When it is located between the phases 1 (material m1) and 2 (material m2), the volume integral over the region ABCD can be problematic, because in this case the material inside the sub-region AD-ef is still m2.

Fig. 1: Problem domain.




Fig. 2: Regular internal region (rectangle here) composed of two different materials: m1 and m2, where the interface e-f between them is irregular.





Instead, if we can find the boundary cell-faces that encompass ABCD, we can do surface integral directly, and the error might be reduced.

The question now is: how do we efficiently find all the boundary cell-faces of an continuous internal region (e.g. using topoSet boxToCell)?

Thanks in advance,


David