[Arcannys]

Hello,

I'm new to the forum.
I'm trying to simulate katabatic winds flowing trough a valley. The first thing i tried was to just try to simulate downward winds due to a regular temperature gradient in free atmosphere setting (cold air falls because of higher density etc..) as well as a normal ISA pressure gradient with no initial speed. But i'm getting really weird results (flow going upwards and faster than speed of light????).

I have a feeling i'm not setting my boundary conditions correctly, but i have no clue what exactly am I doing wrong. I've been trying this in Fuent, would it be a better idea to try it in OpenFoam?

Does anyone have experience in simulating free atmosphere with no wind speed? what boundary conditions should i use?

thanks in advance,
Arcannys~