Fire Modeling Software

 

An image from a NIST computer model shows temperature levels during the 2007 Charleston Sofa Super Store fire. Dark blue is ambient temperature; bright red is about 800 degrees C (1500 degrees F). Credit: NIST

Fire Modeling Software

These fire simulation programs were developed or sponsored by the Fire Research Division at the NIST. The list of programs is divided into two broad categories below: currently-supported software and archival (unsupported) software. In order to get further information or to obtain one of the programs, click on the appropriate name.

Current Software

These models are being actively developed and supported by the laboratory. Details of the software, including download, development, and support information are included on the individual web pages for each model.

  • FDS (Fire Dynamics Simulator) is a computational fluid dynamics (CFD) model of fire-driven fluid flow. The software solves numerically a form of the Navier-Stokes equations appropriate for low-speed, thermally-driven flow, with an emphasis on smoke and heat transport from fires.
  • CFAST (Consolidated Model of Fire and Smoke Transport) is a two-zone fire model used to calculate the evolving distribution of smoke, fire gases and temperature throughout compartments of a building during a fire.

Archival Software

These models are included largely for reference or historical interest and span several decades of development of computational tools in fire research at NIST. As such, they are largely unsupported due to the age of the software.

  • ALOFT-FTTM (A Large Outdoor Fire plume Trajectory model – Flat Terrain) is a computer based model to predict the downwind distribution of smoke particulate and combustion products from large outdoor fires. It solves the fundamental fluid dynamic equations for the smoke plume and its surroundings with flat terrain. The program contains a graphical user interface for input and output and a user modifiable database of fuel and smoke emission parameters. The output can be displayed as downwind, crosswind and vertical smoke concentration contours. Information on using the program is available with on-line help commands in the program.
  • ASCOS (Analysis of Smoke Control Systems) is a program for steady air flow analysis of smoke control systems. This program can analyze any smoke control system that produces pressure differences with the intent of limiting smoke movement in building fire situations. The program is also capable of modeling the stack effect created in taller buildings during extreme temperature conditions. The program input consists of the outside and building temperatures, a description of the building flow network and the flows produced by the ventilation or smoke control system. The output consists of the steady state pressures and flows throughout the building. Another newer program, CONTAM, may be more appropriate to some applications than ASCOS.
  • ASET-B (Available Safe Egress Time – BASIC) is a program for calculating the temperature and position of the hot smoke layer in a single room with closed doors and windows. ASET-B is a compact easy to run program which solves the same equations as ASET. The required program inputs are a heat loss fraction, the height of the fire, the room ceiling height, the room floor area, the maximum time for the simulation, and the rate of heat release of the fire. The program outputs are the temperature and thickness of the hot smoke layer as a function of time.
  • ASMET (Atria Smoke Management Engineering Tools) consists of a set of equations and a zone fire model for analysis of smoke management systems for large spaces such as atria, shopping malls, arcades, sports arenas, exhibition halls and airplane hangers. ASMET is written in C++ language. For program documentation and a description of the input data, the user should refer to NISTIR 5516, Klote, J. H., Method of Predicting Smoke Movement in Atria with Application to Smoke Management, NIST.
  • BREAK1 (Berkeley Algorithm for Breaking Window Glass in a Compartment Fire) is a program which calculates the temperature history of a glass window exposed to user described fire conditions. The calculations are stopped when the glass breaks. The inputs required are the glass thermal conductivity, thermal diffusivity, absorption length, breaking stress, Young’s modulus, thermal coefficient of linear expansion, thickness, emissivity, shading thickness, half-width of window, the ambient temperature, numerical parameters and the time histories of flame radiation from the fire, hot layer temperature and emissivity, and heat transfer coefficients. The outputs are temperature history of the glass normal to the glass surface, and the window breakage time.
  • CCFM (Consolidated Compartment Fire Model version VENTS) is a two-layer zone-type compartment fire model computer code. It simulates conditions due to user-specified fires in a multi-room, multi-level facility. The required inputs are a description of room geometry and vent characteristics (up to 9 rooms, 20 vents), initial state of the inside and outside environment, and fire energy release rates as a functions of time (up to 20 fires). If simulation of concentrations of products of combustion is desired, then product release rates must also be specified (up to three products). Vents can be simple openings between adjacent spaces (natural vents) or fan/duct forced ventilation systems between arbitrary pairs of spaces (forced vents). For forced vents, flow rates and direction can be user-specified or included in the simulation by accounting for user-specified fan and duct characteristics. Wind and stack effects can be taken into account. The program outputs for each room are pressure at the floor, layer interface height, upper/lower layer temperature and (optionally) product concentrations.
  • DETACT-QS and DETACT-T2
    DETACT-QS (DETector ACTuation – Quasi Steady) is a program for calculating the actuation time of thermal devices below unconfined ceilings. It can be used to predict the actuation time of fixed temperature heat detectors and sprinkler heads subject to a user specified fire. DETACT-QS assumes that the thermal device is located in a relatively large area, that is only the fire ceiling flow heats the device and there is no heating from the accumulated hot gases in the room. The required program inputs are the height of the ceiling above the fuel, the distance of the thermal device from the axis of the fire, the actuation temperature of the thermal device, the response time index (RTI) for the device, and the rate of heat release of the fire. The program outputs are the ceiling gas temperature and the device temperature both as a function of time and the time required for device actuation. DETACT-T2 (DETector ACTuation – Time squared) is a program for calculating the actuation time of thermal devices below unconfined ceilings. It can be used to predict the actuation time of fixed temperature and rate of rise heat detectors, and sprinkler heads subject to a user specified fire which grows as the square of time. CT-T2 assumes that the thermal device is located in a relatively large area, that is only the fire ceiling flow heats the device and there is no heating from the accumulated hot gases in the room. The required program inputs are the ambient temperature, the response time index (RTI) for the device, the activation and rate of rise temperatures of the device, height of the ceiling above the fuel, the device spacing and the fire growth rate. The program outputs are the time to device activation and the heat release rate at activation.
  • ELVAC (Elevator Evacuation) is an interactive computer program that estimates the time required to evacuate people from a building with the use of elevators and stairs. It is cautioned that elevators generally are not intended as a means of fire evacuation, and they should not be used during fires. However, it is possible to design elevator systems that for fire emergencies, and ELVAC can be used to evaluate the potential performance of such systems. ELVAC calculates the evacuation time for one group of elevators. If a building has more than one group of elevators, ELVAC can be run on each group separately. Input consists of floor to floor heights, number of people on floors, number of elevators in the group, elevator speed, elevator acceleration, elevator capacity, elevator door type and width, and various inefficiency factors. The output is a table of elevator travel time, round trip time, people moved, and number of round trips for each floor plus the total evacuation time.
  • FIRDEMND simulates the suppression of post flashover charring and non-charring solid-fuel fires in compartments using water sprays from portable hose-nozzle equipment used by the fire departments. The output of the Fire Demand Model (FDM) shows the extinguishing effects of water spray at various flow rates and droplet sizes. The calculations are based on a heat and mass balance accounting for gas and surface cooling, steam-induced smothering, water-spray induced air entrainment, direct extinguishment of the fire by water and the energy transport via inflow and outflow of heat and products of combustion.
  • FIRST (FIRe Simulation Technique) is the direct descendant of the HARVARD V program developed by Howard Emmons and Henri Mitler. The fire may be entered either as a user-specified time-dependent mass loss rate or in terms of fundamental properties of the fuel. In the latter case, the program will predict the fire growth rate by considering the changing oxygen concentration and smoke layer conditions in the room of fire origin. It can also predict the heating and possible ignition of up to three targets. The original fire and targets may also be user specified fires. The required program inputs are the geometrical data describing the rooms and openings, and the thermophysical properties of the ceiling, walls, burning fuel, and targets. The generation rate of soot must be specified, and the generation rates of other species may be specified as a yield of the pyrolysis rate. Among the program outputs are the temperature and thickness of, and species concentrations in, the hot upper layer and also in the cooler, lower layer in each compartment. Also given are wall surface temperatures, heat transfer rates and mass flow rates. MASBANK is used to create and maintain a data base of materials and their fire properties for use by the FIRST program. MASBANK can accommodate 20 properties for up to 50 materials. The program has the capability to add, delete, change, alphabetize and view the material properties in the data bank. Material properties from MASBANK may be transferred directly into the FIRST program.
  • Jet is a model for the prediction of detector activation and gas temperature in the presence of a smoke layer.
  • FPETool (Software and Documentation) is a set of engineering equations useful in estimating potential fire hazard and the response of the space and fire protection systems to the developing hazard. Version 3.2 incorporates an estimate of smoke conditions developing within a room receiving steady-state smoke leakage from an adjacent space. Estimates of human viability resulting from exposure to developing conditions within the room are calculated based upon the smoke temperature and toxicity.
  • LAVENT is a program developed to simulate the environment and the response of sprinkler links in compartment fires with draft curtains and fusible link operated ceiling vents. The model, used to calculate the heating of the fusible links, includes the effects of the ceiling jet and the upper layer of hot gases beneath the ceiling. The required program inputs are the geometrical data describing the compartment, the thermophysical properties of the ceiling, the fire elevation, the time dependent energy release rate of the fire, the fire diameter or energy release rate per area of the fire, the ceiling vent area, the fusible link response-time-index (RTI) and fuse temperature, the fusible link positions along the ceiling, the link assignment to each ceiling vent, and the ambient temperature. A maximum of five ceiling vents and ten fusible links are permitted in the compartment. The program outputs are the temperature, mass and height of the hot upper layer, the temperature of each link, the ceiling jet temperature and velocity at each link, the radial temperature distribution along the interior surface of the ceiling, the radial distribution of the heat flux to the interior and exterior surfaces of the ceiling, the fuse time of each link, and the vent area that has been opened.GRAPH is a graphics program which runs in conjunction with LAVENT. The results for LAVENT are sent to the data file, GRAPH.OUT, after each prescribed time step. GRAPH then allows the user to choose two sets of variables to be plotted on the screen and has the additional capability of hardcopy output.

Direct Link to NIST: http://www.nist.gov/el/fire_protection/buildings/fire-modeling-programs.cfm

These fire simulation programs were developed or sponsored by the Building and Fire Research Laboratory. In order to get further information or to obtain one of the programs, click on the appropriate name.

  • ALOFT-FTTM- A Large Outdoor Fire plume Trajectory model – Flat Terrain
  • ASCOS- Analysis of Smoke Control Systems
  • ASET-B- Available Safe Egree Time – BASIC
  • ASMET- Atria Smoke Management Engineering Tools
  • BREAK1- Berkeley Algorithm for Breaking Window Glass in a Compartment Fire
  • CCFM- Consolidated Compartment Fire Model version VENTS
  • CFAST- Consolidated Fire and Smoke Transport Model
  • DETACT-QS- Detector Actuation – Quasi Steady
  • DETACT-T2- Detector Actuation – Time squared
  • ELVAC- Elevator Evacuation
  • FASTLite- A collection of procedures which builds on the core routines of FIREFORM and the computer model CFAST to provide engineering calculations of various fire phenomena,
  • FIRDEMND- Handheld Hosestream Suppression Model
  • FIRST- FIRe Simulation Technique
  • FPETool- Fire Protection Engineering Tools (equations and fire simulation scenarios)
  • Jet- A Model for the Prediction of Detector Activation and Gas Temperature in the Presence of a Smoke Layer
  • LAVENT- Response of sprinkler links in compartment fires with curtains and ceiling vents
  • NIST Fire Dynamics Simulator and Smokeview – The NIST Fire Dynamics Simulator predicts smoke and/or air flow movement caused by fire, wind, ventilation systems etc. Smokeview visualizes the predictions generated by NIST FDS.

Using Fire Models to Understand Fire Behavior NIST’s fire modeling capabilities can help firefighters understand and predict fire conditions, HERE

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