ALOFT-FTTM Smoke Plume Trajectory Model for Personal Computers
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. Measurements and observations at experimental fires have shown that the downwind distribution of smoke is a complex function of the fire parameters, meteorological conditions and topographic features. To incorporate these features, NIST has developed a smoke plume trajectory model that solves the fundamental fluid dynamic equations for the smoke plume and its surroundings. ALOFT-FT is the public domain version of the model for flat terrain using windows based personal computers. 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.
ALOFT-FT was developed to aid in the planning process for the intentional burning of crude oils spills on water. The program may also be useful in predicting the smoke plume trajectory from other large outdoor fires particularly liquid pool fires.
How ALOFT-FT Differs From Other Models:
Most smoke plume models use relatively simple correlations to describe a smoke plume. These correlations usually produce a Gaussian profile of downwind smoke concentration. While these models may be useful in some circumstances, measurements and observations at experimental burns have shown that the downwind distribution of smoke is not Gaussian. The simple smoke plume models do not capture the observed plume features such as the twin counter-rotating vortices frequently observed. ALOFT-FT solves the fundamental Navier-Stokes equations using an eddy viscosity over a uniform grid which spans the smoke plume and its surroundings. The model inputs include wind speed and variability, atmospheric temperature profile, number of fires, fuel parameters and emission factors. The output is the average concentration of combustion products in each of the computational cells from ground level to the top of the plume. The output can be displayed as downwind, crosswind and vertical concentration contours.
Sample Input Screens
Input Screen for Fire Parameters
Input Screen for Wind Parameters
Input Screen for Temperature Parameters
Input Screen for Fuel Parameters
Sample Output Screens
Summary Output Screen
Horizontal Concentration Output Screen
Downwind Vertical Concentration Output Screen
Vertical Crosswind Concentration Output Screen
For further assistance with viewing this page, contact Kevin B. McGrattan at firstname.lastname@example.org.
Type of software: .exe
Windows 98/ME/NT4/2000/XP® required. The graphics may not work on some Windows 95 computers. The program is a 32 bit application and will NOT run under Window 3.X with win32. There are no plans to support Windows 3.X, Macintosh® or UNIX at this time.
15 MB free disk space to download and install.
Pentium® or better processor recommended.
ALOFT-FT™ is a contribution of the National Institute of Standards and Technology (U.S.) and is not subject to copyright.
ALOFT-FT may be freely distributed.
The runtime libraries distributed with the program are copyrighted and may be used without fees only in conjunction with this program.
As with any research product, it is recommended that the programs be used only by individuals who are knowledgeable concerning the assumptions and limitations. The National Institute of Standards and Technology makes no warranties, either expressed or implied, with respect to the software and documentation, including but not limited to the implied warranties of suitability and fitness for a particular purpose.
Every effort has been made to ensure the accuracy and correctness of the programs and information.
All files are in self-extracting compressed file format. To expand the file, copy it to a empty directory. Execute the file either by double clicking on the file name from Windows Explorer or other file manager, or enter <FILENAME>.EXE from the RUN command line with appropriate drive and path name.
To start the installation either execute SETUP.EXE or use the Add/Remove Programs feature in the Control Panel folder. When you see the statement "Windows was unable to locate the installation program…" use the browse feature to locate the folder you created for the program and select SETUP.EXE.
For Windows98/ME/NT4/2000/XP only!
AFT310CD.EXE (7,880 Kb)
Same files in zip format.
AFT310CD.ZIP (7,850 Kb)
Sample Data and Output Files:
AFTDATA.EXE is a self-extracting compressed file containing sample ALOFT-FT input data and output files. To expand the file, copy it to a empty directory. Execute AFTDATA.EXE either by double clicking on the file name from Windows Explorer or other file manager, or enter AFTDATA.EXE from the RUN command line with appropriate drive and path name. If you open the sample data file with ALOFT-FT, you can view an example of the graphical output without having run the computational part of the program for your own case which may take 10 minutes or more.
AFTDATA.EXE (406 KB)
Same files in zip format.
AFTDATA.ZIP (377 KB)
The principal technical reference for ALOFT-FT is provided in self-expanding compressed format. Once expanded the document is in PDF format. To read this document you will need a PDF viewer such as the Adobe® Acrobat® Reader which may be downloaded at http://www.adobe.com/products/reader.html. Additional ALOFT references may be found in Publications by searching under the author name McGrattan.
NISTIR 5958 Smoke Plume Trajectory From In Situ Burning of Crude Oil in Alaska: Field Experiments and Modeling of Complex Terrain. McGrattan, K. B.; Baum, H. R.; Walton, W. D.; Trelles, J. J.
NISTIR 5958 includes the equations and comparison of model results with experiments for ALOFT-FT and ALOFT-CT. This is a comprehensive reference but it is a large file.
NISTIR_5958.PDF (15,189 KB)
For further information, consult the Frequently Asked Questions page.
Kevin B. McGrattan