Guidelines for the Use of CFD Simulations for Fire and Smoke Modeling

摘要

This paper presents a "back to basics "examination of CFD techniques as they relate to the modeling of fire development and smoke production. The paper aims at providing a better understanding of fundamental fire dynamics concepts and their limitations and impact on model predictions. Key issues examined include grid resolution, plume entrainment rates, combustion models, smoke modeling, radiative fraction, non-orthogonal geometries, interface height calculation, and boundary layer modeling. Guidelines for the proper treatment of each issue are given as well as advice on avoiding common pitfalls. The NIST Fire Dynamics Simulator (FDS) software is discussed in detail; however, many of the issues, results, and discussions are applicable to other CFD models. The fire scenarios considered deal with fires in compartments and atria due to their relevance to ASHRAE members. Where appropriate, comparative results based on the sample models provided with FDS are presented.