Transport phenomena of turbulent fire spread through compartment connected to vertical shaft in tall building

Abstract

The purpose of this paper is to understand the growth and spread of fire through compartment connected to vertical shaft in tall building. The transport phenomena due to fire have been modeled as buoyancy induced turbulent flow in tall building. The governing equations comprise the Reynolds averaged Navier–Stokes (RANS) equations with the K–ɛ turbulence model in a stream function–vorticity formulation approach. The governing equations are solved by high accuracy compact finite difference schemes with the four stage Runge–Kutta method for time integration. Results are reported for two different Grashof numbers Gr = 1010 and 1011. The effects of vertical passage between compartment and shaft, multiple vertical vents and significance of flow through ceiling vent in tall building are presented. The thermal plume growth rate, the ambient entrainment flow rate and the bidirectional oscillatory nature at the vent openings are reported. A significant change in the flow behavior is observed by varying the size of vertical passage between compartment and shaft. The flow behavior through vertical and ceiling vents is presented. The flow patterns in the shaft show complex flow structure with multi-recirculating convective cells. The present results are matching with the numerical and experimental results available in the literature.