FDS and Smokeview

Fire Dynamics Simulator is a CFD solver built specifically for fires: it computes hot gas flow, heat release rate, temperatures, species concentrations and visibility, at room and whole-building scale. Smokeview is the companion viewer that renders the result as a 3D animation of flame, smoke and gas layers.

This is the tool behind most engineering fire safety calculations worldwide — smoke extraction in underground car parks, atrium smoke control, evacuation time against fire spread. It is developed by NIST and validated against a large body of fire experiments.

What is missing: input is a text file, and setting up a complex case takes expertise. Commercial products in this field are largely graphical front ends around the same engine.