Coupling of models for fire dynamics and pedestrian dynamics to estimate the required safe egress time (RSET)

Smoke from fires impairs visibility, endangering safe evacuation. Smoke can disorient occupants and obscure safety signs, typically assessed using Jin’s law. This method has limits as it assumes uniform smoke distribution, which is often not the case in actual fires.

This paper introduces visibility maps that use computational fluid dynamics (CFD) simulations to evaluate visibility in varying smoke conditions more accurately. The model refines Jin's law for non-uniform smoke by applying ray casting techniques and evaluates exit sign visibility along evacuation routes. It accounts for building design and other factors affecting sightlines.

Integrating these maps with JuPedSim, an open-source pedestrian simulation software, enhances agent decision-making based on visibility during fire events. The combined approach of fire and pedestrian dynamics models better estimates safe evacuation times, highlighting the complexities of modeling occupant behavior in fire emergencies.