Mathematical modeling and computation of fire induced turbulent flow in partial enclosures

The purpose of this paper is to understand the growth and spread of fires in ceiling vented enclosures. The transport phenomena due to fire have been modeled as buoyancy-induced turbulent flow in partial enclosures. The governing equations comprises the Reynolds averaged Navier–Stokes (RANS) equations with k–∊k–∊ turbulence model in stream function–vorticity formulation approach. The governing equations are solved by high accuracy compact finite difference schemes with four stage Runge–Kutta method for time integration. Results are reported for Grashof numbers varied from 108108 to 10101010. The effects of multiple heat sources in rectangular enclosure and ceiling vent aspect ratio in square enclosure are investigated. The thermal plume growth rate, ambient entrainment flow rate and the oscillatory nature at the vent opening are reported. As the Grashof number increases the effect of entrained ambient air is significant with higher volume flow rates through ceiling vent. A bidirectional flow is visualized at the ceiling opening. The distance between two heat sources governs the unified and independent behavior of thermal plumes. Present results are matching very well with the numerical and experimental results available in literature.