[ThatGuy]

Hello all,

I'm tired of this, and there's no way I can get this big geometry to work. Would any of you bother to take a look at my file?

I'll try to explain the problem.

I want to simulate in a very simplicate way what does the air do inside a hot air balloon. I have 2 regions: 1 is for the environment, with some large walls in the bottom in order to simulate the "far region" where velocity goes to 0; 2 is for the flame region, where I put a volumetric heat source with some trial values in order to have a high temperature. Region 2 is porous (porosity 1). The interfaces are baffle porous, conducting. On parts in contact, I put some pressure outlet boundaries, even if in small geometry I tested everything works pretty much the same.
Physics model uses coupled energy, ideal steady (but i also tried implicit unsteady) gas, k-e turbulence, and gravity. Gravity is oriented along negative x. The sim is axisymmetric around x.
When something starts to work, I'll consider the convection alongside the balloon and some other minor tweaks.

Thank you to everyone who will take sometimes to have a look at this. Obviously, if you can think of a better way to do the whole thing, I'm open to every suggestion.

I could not upload the attachment, so I give you the dropbox link

https://www.dropbox.com/s/u6f1figgy3...ssa02.sim?dl=0