A two-zone fire growth and smoke movement model for multi-compartment buildings

A ire growth and smoke movement model for a multi-compartment building has been developed at the National Research Council of Canada. This development is primarily intended to help evaluate the risk from fires in buildings. T his paper presents the related physical models, numerical methods, and some verification examples. The 2-zone ordinary differential equations (ODEs) a re derived for the compartments with fire or smoke. The four independent va riables for one compartment are selected as pressure, enthalpy of upper lay er, and mass of upper and lower layers. The implemented fire sub-models are introduced, including combustion, fluid flow and heat transfer models. For each compartment without smoke or fire, a non-linear algebraic equation ba sed on mass conservation is used instead of the ODEs. The numerical solutio n of the governing equations is obtained using a room by room iteration met hod. In this algorithm, an existing ODE solver, LSODA, has been modified an d used to solve the stiff ODEs, and the Steffensen Acceleration Method is u sed to solve the algebraic equations. Experimental data for single- and two -compartment fire tests are compared to the predictions of the model. The c omparison shows favourable results, especially for the upper layer gas temp erature, interface height, and vent flow rate. Crown copyright (C) 2000 Pub lished by Elsevier Science Ltd. All rights reserved.