2-ZONE MODEL FOR A SINGLE-ROOM FIRE

Frequently, computational models are used to predict fire temperatures and the migration of smoke which result from a single room fire. Many of these models, commonly called two-zone models, assume a smoky layer accumulates at the ceiling and a relatively clear air layer exists near the floor. This paper describes an improved two-zone fire model and a computer program called GTFIRE which studies the effects of room geometry and fire characteristics on the air temperature and pressure within the room and on the smoke movement from the room. Unlike existing models, this program includes a more exact energy analysis, assumes the air in the room has variable specific heats, and accounts for pressure changes in the air with respect to height. GTFIRE is executed for a number of fire scenarios to show how the placement of vents in the room and changes in room geometry affect the movement and development of smoke during the fire. Finally, program output is compared with existing two-zone models to establish how the mathematical formulation improves the accuracy of fire predictions.