[Bido14]

I have a room ( Fire Compartment ) that is (2 x 2 x 2)m , it has four windows on the side walls, and a circular fuel inlet ( 18 mm diameter) in the center of the floor (Bottom).

what is the best way to mesh it?

100 or 50 mm grid size is preferred

[-mAx-]

post pictures please

[Bido14]

You can find attached a photo for the room ( 2x2x2 m) with 4 windows each (125 x 500 mm) , the fuel inlet is a circle at the bottom of diameter 18 mm or cm.

I need to ignite a stable fire from methane, and i am not sure of the mesh size or fuel size, Please help

[-mAx-]

if you don't need full hexa mesh, I would mesh it with tetra-hexcore and you can assign a size function in your inlet area.
Thus you need at least 8-10 cellls in your inlet diameter.