Numerical simulation of fire-induced flow through a stairwell.pdf

ARTICLE IN PRESS0360-1323/$ - se doi:10.1016/j.bu
Correspond 9045. E-mail addrBuilding and Environment 40 (2005) 183–194 /locate/buildenvNumerical simulation of fire-induced flow through a stairwell T.X. Qina, Y.C. Guoa, C.K. Chanb,
, K.S. Lauc, W.Y. Lina aDepartment of Engineering Mechanics, Tsinghua University, Beijing 100084, China bDepartment of Applied Mathematics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong cDepartment of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Received 5 February 2004; received in revised form 14 July 2004; accepted 21 July 2004Abstract Smoke movement and ambient airflow in a stairwell under fire scenarios are studied numerically using large eddy simulation. Numerical investigation is performed on a typical two-storey confined stairwell, with an open door on the top floor and a fire source on the ground floor. Results show the existence of fairly distinct layers of hot smoke and ambient air under different fire scenarios. It is found that heat release rate has a remarkable effect on distributions of smoke temperature, velocity and oxygen concentration. This paper indicates that detailed patterns of velocity, temperature and species concentration and their evolutions can be predicted by numerical simulation of a stairwell during a fire. r 2004 Elsevier Ltd. All rights reserved. Keywords: Fire-induced flow; Stairwell; Large eddy simulation1. Introduction During a fire, the stairwell joining different floors of a building takes the combustion products outside the building, and at the same time, draws air into the building. The chimney effect of the stairwell accelerates the spread of smoke. Experimental and numerical studies of buoyancy-driven flow in stairwells have been studied [1–4], and most of these efforts have been focused on gas flow in the stairwell by localized heating. It was found that a layer of smoke spreads in a typical stairwell with a clapboard structure, but li