[rupak504]

hello

I am simulating a two-phase air-water flow using the VOF method. It's a very simple problem, air bubble rising up under buoyancy force. For Dynamic meshing, I am using Adaption by Gradient, where I am using this setting Grad_adaption.jpg, with this setting I am getting this refined at middle.PNG, but what I want is this octree.jpg.


Any help would be highly appreciated

regards

[vinerm]

You may be using wrong values for the threshold. Do note that volume fraction is bounded between 0 and 1 but not its gradient. You should first plot the gradient contours and then check the values around the bubble. Within a particular phase, gradient is always 0, so, around the bubble it would have some value. But if you use very small value, then it would refine most of the domain.