I’m in all sorts of trouble, I cannot get my model stable. I’ve tried playing with the HTab, the cross section intervals, the timesteps, you name it. I’m trying to break a dam and can’t get the model to run with the same parameters for 1D and be stable as 2D and be stable and 1D / 2D combined running at all.
have you tried reducing the cell size, for a dam break I assume you will get large flows coming down steep lopes at the dam interface that could be causing problems. The other thing to do is check the cells where the instabilities are forming to see the problem spots.