Hi
forces on boundaries is a waste subject. But it is an important one because often the solutions passes through these forces.
Mostly such forces re obtained by gradient integration over the boundary surfaces, but these gradients must be well defined to reach the desired precision.
in comsol V3.5 you have the surface force variales, specifically for this, but they apply only to external constraint surfaces, otherwise you must consider weak form terms (simple to turn on in the "physics" button) but still you need to adapt your model.
I can only suggest to read through the doc (I agree there are a lot to read, and its tough and dense, but here we are rewriting Physics), specially go through the models that apply to your case and your physics, check the discussion forum, the Model exchange, all the examples on the web, and come back here too
Good luck
Ivar
forces on boundaries is a waste subject. But it is an important one because often the solutions passes through these forces.
Mostly such forces re obtained by gradient integration over the boundary surfaces, but these gradients must be well defined to reach the desired precision.
in comsol V3.5 you have the surface force variales, specifically for this, but they apply only to external constraint surfaces, otherwise you must consider weak form terms (simple to turn on in the "physics" button) but still you need to adapt your model.
I can only suggest to read through the doc (I agree there are a lot to read, and its tough and dense, but here we are rewriting Physics), specially go through the models that apply to your case and your physics, check the discussion forum, the Model exchange, all the examples on the web, and come back here too
Good luck
Ivar
