Fire and Smoke Simulator (FSSIM) Version 1 - Theory Manual

Abstract : There currently exists a number of computational tools for examining the effects of a fire that can be applied to a ship and its crew. One could use hand calculations for examining simple scenarios in single compartments. Simple rules can be used to extend this approach to multiple compartments. Zone models are suitable for examining somewhat more complex, time-dependent scenarios involving multiple compartments and levels, but stability can be a problem for multi-level scenarios with Heating, Ventilation, and Air Conditioning (HVAC) systems, and for post- flashover conditions. Computational fluid dynamics (CFD) models can yield detailed information about temperatures, heat fluxes, and species concentrations; however, the time penalty of this approach currently makes using CFD unfeasible for long periods of real time or large computational domains. There is another class of models that have traditionally played supporting roles in fire modeling. This class is constituted by a variety of network models, which are used for ventilation systems in buildings or fluid flow in piping networks. These models, however, lack specific physics required for fire modeling. To meet the computational speed and algorithm requirements, it was decided to develop Fire and Smoke Simulator (FSSIM) as a network fire model. This document (Theory Manual) describes the equations solved, and the solution algorithm for the heat and mass transfer along with the equations and algorithms for FSSlM sub-models.