Numerical simulations of grass fires using a coupled atmosphere-fire model: Basic fire behavior and dependence on wind speed

Rodman R. Linn, P. Cunningham

Research output: Contribution to journalArticle

94 Citations (Scopus)

Abstract

Numerical simulations using a fire model, FIRETEC, coupled to an atmospheric dynamics model, HIGRAD, are examined to investigate several fundamental aspects of fire behavior in grasslands, and specifically the dependence of this behavior on the ambient atmospheric winds and on the initial length of the fire line. The FIRETEC model is based on a multi-phase transport approach, and incorporates representations of the physical processes that govern wildfires, such as combustion and radiative and convective heat exchange. Results from the coupled model show that the forward spread of the simulated fires increases with increasing ambient wind speed, and the spread rates are consistent with those observed in field experiments of grass fires; however, the forward spread also depends significantly on the initial length of the fire line, and for a given ambient wind speed the spread rate for long (100 m) lines is greater than that for short (16 m) lines. The spread of the simulated fires in the lateral direction also depends on the ambient wind speed and the length of the fire line, and a possible explanation for this effect is given. For weak ambient winds, the shape of the fire perimeter is dramatically different from that seen with higher wind speeds. The shape of the fire perimeter is also shown to depend on the initial length of the fire line. These differences in fire behavior are attributed to the differences in the nature of the coupled atmosphere-fire interactions among these cases, and are described in terms of the complex interplay between radiative and convective heat transfer. Copyright 2005 by the American Geophysical Union.
Original languageEnglish
JournalJournal of Geophysical Research: Atmospheres
Volume110
Issue number13
Early online date6 Jul 2005
DOIs
Publication statusPublished - 16 Jul 2005

Fingerprint

fire behavior
wind velocity
atmosphere
simulation
grass fire
atmospheric dynamics
wildfire
heat transfer
combustion
grassland

Bibliographical note

Cited By :69

Export Date: 16 May 2017

Correspondence Address: Linn, R.R.; Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, United States; email: cunningham@met.fsu.edu

References: Alexander, M.E., Estimating the length-to-breadth ratio of elliptical forest fire patterns Proceedings of the Eighth Conference on Fire and Forest Meteorology, pp. 287-304. , edited by L. R. Donoghue und R. E. Martin, Soc. of Am. For., Bethesda. Md; Andersen, H.E., Aids to determining fuel models for estimating fire behavior Gen. Tech. Rep., INT-122, 22p. , U.S. Dep. of Agric. For. Serv., Ogden, Utah; Anderson, H.E., Predicting wind-driven wild land fire size and shape Res. Pap., INT-305, 26p. , U.S. Dep. of Agric. For. Serv., Ogden, Utah; Andrews, P.L., Bevins, C.D., Sell, R.C., BehavePlus fire modeling system, version 2.0: User's guide Gen., Tech. Rep, RMRS-GTR-106WWW, 132p. , U.S. Dep. of Agric. For, Serv., Ogden, Utah; Beer, T., The interaction of wind and fire Boundary Laer Meteorol., 54, pp. 287-308; Beer, T., The speed of a fire front and its dependence on wind speed Int. J. Widland Fire, 3, pp. 193-202; Burgan, R.E., Revisions to the 1978 National Fire-Danger Rating System Res. Pap., SE-273, 39p. , U.S. Dep. of Agric. For. Serv., Asheville, N. C; Carrier, G.F., Fendell, F.E., Wolff, M.F., Wind-aided firespread across arrays of discrete fuel elements, I. Theory Combust. Sci. Tech., 75, pp. 31-51; Catchpole, W.R., Catchpole, E.A., Butler, B.W., Rothermel, R.C., Morris, G.A., Latham, D.J., Rate of spread of free- Burning fires in woody fuels in a wind tunnel Combust. Sci. Tech., 131, pp. 1-37; Cheney, N.P., Could, J.S., Fire growth in grassland fuels Int. J. Wildland Fire, 5, pp. 237-244; Cheney, N.P., Sullivan, A., Crassfires: Fuel. Weather and Fire Behaviour, 112p. , CSIRO, Collingwood, Victoria, Australia; Cheney, N.P., Could, J.S., Catchpole, W.R., The influence of fuel, weather and fire shape variables on fire-spread in grasslands Int. J. Wildland Fire, 3, pp. 31-44; Cheney, N.P., Gould, J.S., Catchpole, W.R., Prediction of fire spread in grasslands Int. J. Wildland Fire, 8, pp. 1-13; Clark, T.L., Jenkins, M.A., Coen, J.L., Packham, D.R., A coupled atmosphere-fire model: Convective feedback on fire line dynamics J. Appl. Meteorol., 35, pp. 875-901; Clark, T.L., Jenkins, M.A., Coen, J.L., Packham, D.R., A coupled atmosphere-fire model: Role of the convective Froude number and dynamic fingering at the fireline Int. J. Wildland Fire, 6, pp. 177-190; Clark, T.L., Griffiths, M., Reeder, M.J., Latham, D., Numerical simulations of grassland fires in the Northern Territory, Australia: A new subgrid-scale fire parameterization J. Geophys. Res., 108 (D18), p. 4589. , doi:10.1029/2002JD003340; Clark, T.L., Coen, J.L., Latham, D., Description of a coupled atmosphere-fire model Int. J. Wildland Fire, 13, pp. 49-63; Cunningham, P., Goodrick, S.L., Hussaini, M.Y., Linn, R.R., Coherent vortical structures in numerical simulations of buoyant plumes from wildland fires Int. J. Wildland Fire, 14, pp. 61-75; Drysdale, D., An Introduction to Fire Dynamics, 2nd Ed., 470p. , John Wiley, Hoboken, N. J; Finney, M.A., FARSITE: Fire area simulator - Model development and evaluation Res. Pap., RMRS-RP-4, 47p. , U.S. Dep. of Agric. For. Serv., Ogden, Utah; Fons, W.T., Analysis of fire spread in light forest fuels J. Agric. Res., 72, pp. 93-121; Grishin, A.M., Mathematical Modeling of Forest Fires and New Methods of Fighting Them, 390p. , edited by F. A. Albini, Tomsk State Univ., Tomsk, Russia; Heilman, W.E., Fast, J.D., Simulations of horizontal roll vortex development above lines of extreme surface heating Int. J. Wildland Fire, 2, pp. 55-68; Larini, M., Giroud, F., Porterie, B., Loraud, J.-C., A multiphase formulation for fire propagation in heterogeneous combustible media Int. J. Heat Mans Transf., 41, pp. 881-897; Linn, R.R., A transport model for prediction of wildfire behavior Sci. Rep., LA-13334-T, 195p. , Los Alamos Natl. Lab., Los Alamos, N. M; Linn, R.R., Harlow, F.H., Mixing-limited transport model used for description of wildfires Computational Technologies for Fluid/Thermal/Structural/Chemical Systems with Industrial Applications, 377 (2), pp. 161-168. , PVP edited by C. R. Kleijn, S. Kawano, and V. V. Kudriavtsev, Am. Soc. of Mech. Eng., New York; Linn, R.R., Reisner, J.M., Colman, J.J., Winterkamp, J., Studying wildfire behavior using FIRETEC Int. J. Wildland Fire, 11, pp. 233-246; Morvan, D., Dupuy, J.-L., Modeling of fire spread through a forest fuel bed using a multiphase formulation Cambust. Flame, 127, pp. 1981-1994; Porterie, B., Morvan, D., Loraud, J.-C., Larini, M., Firespread through fuel beds: Modeling of wind-aided fires and induced hydrodynamics Phys. Fluids, 12, pp. 1762-1782; Rehm, R.G., Evans, D.D., Mell, W.E., Hostikka, S., McGrattan, K.B., Forney, G.P., Bouldin, C., Baker, E., Neighborhood-scale fire spread 5th Symposium on Fire and Forest Meteorology, , paper presented, Am. Meteorol. Soc., Orlando, Fia., 16-20 Nov; Reisner, J.M., Wynne, S., Margolin, L., Linn, R.R., Coupled atmospheric fire modeling employing the method of averages Mon. Weather Rev., 128, pp. 3683-3691; Rothermel, R.C., A mathematical model for predicting fire spread in wildland fuels Res. Pap., INT-115, 40p. , U.S. Dep. of Agric. For. Serv., Ogden, Utah; Sneeuwjagt, R.J., Frandsen, W.H., Behavior of experimental grass fires vs. predictions based on Rothennel's fire model Can. J. For. Res., 7, pp. 357-367; Stephens, G.L., The parameterization of radiation for numerical weather prediction and climate models Mon. Weather Rev., 112, pp. 827-867; Weise, D.R., Modelling Wind and Slope-induced Wildland Fire Behavior, 130p. , Ph.D. dissertation, Univ. of Calif, Berkeley; Wilson, C.C., Sorenson, J.C., Some common denominators of fire behavior on tragedy and near-miss forest fires Publ. NA-GR-8, 31p. , U.S. Dep. of Agric. For. Serv., Broomall, Pa; Wolff, M.F., Carrier, G.F., Fendell, F.E., Wind-aided firespread across arrays of discrete fuel elements. II. Experiment Combust. Sci. Tech., 77, pp. 261-289

Keywords

  • Computer simulation
  • Fires
  • Heat convection
  • Mathematical models
  • Numerical analysis
  • Wind effects
  • atmospheric modeling
  • combustion
  • grassland
  • heat transfer
  • numerical method
  • radiative forcing
  • thermal convection
  • wildfire
  • wind velocity

Cite this

Numerical simulations of grass fires using a coupled atmosphere-fire model : Basic fire behavior and dependence on wind speed. / Linn, Rodman R.; Cunningham, P.

In: Journal of Geophysical Research: Atmospheres, Vol. 110, No. 13, 16.07.2005.

Research output: Contribution to journalArticle

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title = "Numerical simulations of grass fires using a coupled atmosphere-fire model: Basic fire behavior and dependence on wind speed",
abstract = "Numerical simulations using a fire model, FIRETEC, coupled to an atmospheric dynamics model, HIGRAD, are examined to investigate several fundamental aspects of fire behavior in grasslands, and specifically the dependence of this behavior on the ambient atmospheric winds and on the initial length of the fire line. The FIRETEC model is based on a multi-phase transport approach, and incorporates representations of the physical processes that govern wildfires, such as combustion and radiative and convective heat exchange. Results from the coupled model show that the forward spread of the simulated fires increases with increasing ambient wind speed, and the spread rates are consistent with those observed in field experiments of grass fires; however, the forward spread also depends significantly on the initial length of the fire line, and for a given ambient wind speed the spread rate for long (100 m) lines is greater than that for short (16 m) lines. The spread of the simulated fires in the lateral direction also depends on the ambient wind speed and the length of the fire line, and a possible explanation for this effect is given. For weak ambient winds, the shape of the fire perimeter is dramatically different from that seen with higher wind speeds. The shape of the fire perimeter is also shown to depend on the initial length of the fire line. These differences in fire behavior are attributed to the differences in the nature of the coupled atmosphere-fire interactions among these cases, and are described in terms of the complex interplay between radiative and convective heat transfer. Copyright 2005 by the American Geophysical Union.",
keywords = "Computer simulation, Fires, Heat convection, Mathematical models, Numerical analysis, Wind effects, atmospheric modeling, combustion, grassland, heat transfer, numerical method, radiative forcing, thermal convection, wildfire, wind velocity",
author = "Linn, {Rodman R.} and P. Cunningham",
note = "Cited By :69 Export Date: 16 May 2017 Correspondence Address: Linn, R.R.; Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, United States; email: cunningham@met.fsu.edu References: Alexander, M.E., Estimating the length-to-breadth ratio of elliptical forest fire patterns Proceedings of the Eighth Conference on Fire and Forest Meteorology, pp. 287-304. , edited by L. R. Donoghue und R. E. Martin, Soc. of Am. For., Bethesda. Md; Andersen, H.E., Aids to determining fuel models for estimating fire behavior Gen. Tech. Rep., INT-122, 22p. , U.S. Dep. of Agric. For. Serv., Ogden, Utah; Anderson, H.E., Predicting wind-driven wild land fire size and shape Res. Pap., INT-305, 26p. , U.S. Dep. of Agric. For. Serv., Ogden, Utah; Andrews, P.L., Bevins, C.D., Sell, R.C., BehavePlus fire modeling system, version 2.0: User's guide Gen., Tech. Rep, RMRS-GTR-106WWW, 132p. , U.S. Dep. of Agric. For, Serv., Ogden, Utah; Beer, T., The interaction of wind and fire Boundary Laer Meteorol., 54, pp. 287-308; Beer, T., The speed of a fire front and its dependence on wind speed Int. J. Widland Fire, 3, pp. 193-202; Burgan, R.E., Revisions to the 1978 National Fire-Danger Rating System Res. Pap., SE-273, 39p. , U.S. Dep. of Agric. For. Serv., Asheville, N. C; Carrier, G.F., Fendell, F.E., Wolff, M.F., Wind-aided firespread across arrays of discrete fuel elements, I. Theory Combust. Sci. Tech., 75, pp. 31-51; Catchpole, W.R., Catchpole, E.A., Butler, B.W., Rothermel, R.C., Morris, G.A., Latham, D.J., Rate of spread of free- Burning fires in woody fuels in a wind tunnel Combust. Sci. Tech., 131, pp. 1-37; Cheney, N.P., Could, J.S., Fire growth in grassland fuels Int. J. Wildland Fire, 5, pp. 237-244; Cheney, N.P., Sullivan, A., Crassfires: Fuel. Weather and Fire Behaviour, 112p. , CSIRO, Collingwood, Victoria, Australia; Cheney, N.P., Could, J.S., Catchpole, W.R., The influence of fuel, weather and fire shape variables on fire-spread in grasslands Int. J. Wildland Fire, 3, pp. 31-44; Cheney, N.P., Gould, J.S., Catchpole, W.R., Prediction of fire spread in grasslands Int. J. Wildland Fire, 8, pp. 1-13; Clark, T.L., Jenkins, M.A., Coen, J.L., Packham, D.R., A coupled atmosphere-fire model: Convective feedback on fire line dynamics J. Appl. Meteorol., 35, pp. 875-901; Clark, T.L., Jenkins, M.A., Coen, J.L., Packham, D.R., A coupled atmosphere-fire model: Role of the convective Froude number and dynamic fingering at the fireline Int. J. Wildland Fire, 6, pp. 177-190; Clark, T.L., Griffiths, M., Reeder, M.J., Latham, D., Numerical simulations of grassland fires in the Northern Territory, Australia: A new subgrid-scale fire parameterization J. Geophys. Res., 108 (D18), p. 4589. , doi:10.1029/2002JD003340; Clark, T.L., Coen, J.L., Latham, D., Description of a coupled atmosphere-fire model Int. J. Wildland Fire, 13, pp. 49-63; Cunningham, P., Goodrick, S.L., Hussaini, M.Y., Linn, R.R., Coherent vortical structures in numerical simulations of buoyant plumes from wildland fires Int. J. Wildland Fire, 14, pp. 61-75; Drysdale, D., An Introduction to Fire Dynamics, 2nd Ed., 470p. , John Wiley, Hoboken, N. J; Finney, M.A., FARSITE: Fire area simulator - Model development and evaluation Res. Pap., RMRS-RP-4, 47p. , U.S. Dep. of Agric. For. Serv., Ogden, Utah; Fons, W.T., Analysis of fire spread in light forest fuels J. Agric. Res., 72, pp. 93-121; Grishin, A.M., Mathematical Modeling of Forest Fires and New Methods of Fighting Them, 390p. , edited by F. A. Albini, Tomsk State Univ., Tomsk, Russia; Heilman, W.E., Fast, J.D., Simulations of horizontal roll vortex development above lines of extreme surface heating Int. J. Wildland Fire, 2, pp. 55-68; Larini, M., Giroud, F., Porterie, B., Loraud, J.-C., A multiphase formulation for fire propagation in heterogeneous combustible media Int. J. Heat Mans Transf., 41, pp. 881-897; Linn, R.R., A transport model for prediction of wildfire behavior Sci. Rep., LA-13334-T, 195p. , Los Alamos Natl. Lab., Los Alamos, N. M; Linn, R.R., Harlow, F.H., Mixing-limited transport model used for description of wildfires Computational Technologies for Fluid/Thermal/Structural/Chemical Systems with Industrial Applications, 377 (2), pp. 161-168. , PVP edited by C. R. Kleijn, S. Kawano, and V. V. Kudriavtsev, Am. Soc. of Mech. Eng., New York; Linn, R.R., Reisner, J.M., Colman, J.J., Winterkamp, J., Studying wildfire behavior using FIRETEC Int. J. Wildland Fire, 11, pp. 233-246; Morvan, D., Dupuy, J.-L., Modeling of fire spread through a forest fuel bed using a multiphase formulation Cambust. Flame, 127, pp. 1981-1994; Porterie, B., Morvan, D., Loraud, J.-C., Larini, M., Firespread through fuel beds: Modeling of wind-aided fires and induced hydrodynamics Phys. Fluids, 12, pp. 1762-1782; Rehm, R.G., Evans, D.D., Mell, W.E., Hostikka, S., McGrattan, K.B., Forney, G.P., Bouldin, C., Baker, E., Neighborhood-scale fire spread 5th Symposium on Fire and Forest Meteorology, , paper presented, Am. Meteorol. Soc., Orlando, Fia., 16-20 Nov; Reisner, J.M., Wynne, S., Margolin, L., Linn, R.R., Coupled atmospheric fire modeling employing the method of averages Mon. Weather Rev., 128, pp. 3683-3691; Rothermel, R.C., A mathematical model for predicting fire spread in wildland fuels Res. Pap., INT-115, 40p. , U.S. Dep. of Agric. For. Serv., Ogden, Utah; Sneeuwjagt, R.J., Frandsen, W.H., Behavior of experimental grass fires vs. predictions based on Rothennel's fire model Can. J. For. Res., 7, pp. 357-367; Stephens, G.L., The parameterization of radiation for numerical weather prediction and climate models Mon. Weather Rev., 112, pp. 827-867; Weise, D.R., Modelling Wind and Slope-induced Wildland Fire Behavior, 130p. , Ph.D. dissertation, Univ. of Calif, Berkeley; Wilson, C.C., Sorenson, J.C., Some common denominators of fire behavior on tragedy and near-miss forest fires Publ. NA-GR-8, 31p. , U.S. Dep. of Agric. For. Serv., Broomall, Pa; Wolff, M.F., Carrier, G.F., Fendell, F.E., Wind-aided firespread across arrays of discrete fuel elements. II. Experiment Combust. Sci. Tech., 77, pp. 261-289",
year = "2005",
month = "7",
day = "16",
doi = "10.1029/2004JD005597",
language = "English",
volume = "110",
journal = "Journal of Geophysical Research: Atmospheres",
issn = "2169-897X",
publisher = "American Geophysical Union",
number = "13",

}

TY - JOUR

T1 - Numerical simulations of grass fires using a coupled atmosphere-fire model

T2 - Basic fire behavior and dependence on wind speed

AU - Linn, Rodman R.

AU - Cunningham, P.

N1 - Cited By :69 Export Date: 16 May 2017 Correspondence Address: Linn, R.R.; Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, United States; email: cunningham@met.fsu.edu References: Alexander, M.E., Estimating the length-to-breadth ratio of elliptical forest fire patterns Proceedings of the Eighth Conference on Fire and Forest Meteorology, pp. 287-304. , edited by L. R. Donoghue und R. E. Martin, Soc. of Am. For., Bethesda. Md; Andersen, H.E., Aids to determining fuel models for estimating fire behavior Gen. Tech. Rep., INT-122, 22p. , U.S. Dep. of Agric. For. Serv., Ogden, Utah; Anderson, H.E., Predicting wind-driven wild land fire size and shape Res. Pap., INT-305, 26p. , U.S. Dep. of Agric. For. Serv., Ogden, Utah; Andrews, P.L., Bevins, C.D., Sell, R.C., BehavePlus fire modeling system, version 2.0: User's guide Gen., Tech. Rep, RMRS-GTR-106WWW, 132p. , U.S. Dep. of Agric. For, Serv., Ogden, Utah; Beer, T., The interaction of wind and fire Boundary Laer Meteorol., 54, pp. 287-308; Beer, T., The speed of a fire front and its dependence on wind speed Int. J. Widland Fire, 3, pp. 193-202; Burgan, R.E., Revisions to the 1978 National Fire-Danger Rating System Res. Pap., SE-273, 39p. , U.S. Dep. of Agric. For. Serv., Asheville, N. C; Carrier, G.F., Fendell, F.E., Wolff, M.F., Wind-aided firespread across arrays of discrete fuel elements, I. Theory Combust. Sci. Tech., 75, pp. 31-51; Catchpole, W.R., Catchpole, E.A., Butler, B.W., Rothermel, R.C., Morris, G.A., Latham, D.J., Rate of spread of free- Burning fires in woody fuels in a wind tunnel Combust. Sci. Tech., 131, pp. 1-37; Cheney, N.P., Could, J.S., Fire growth in grassland fuels Int. J. Wildland Fire, 5, pp. 237-244; Cheney, N.P., Sullivan, A., Crassfires: Fuel. Weather and Fire Behaviour, 112p. , CSIRO, Collingwood, Victoria, Australia; Cheney, N.P., Could, J.S., Catchpole, W.R., The influence of fuel, weather and fire shape variables on fire-spread in grasslands Int. J. Wildland Fire, 3, pp. 31-44; Cheney, N.P., Gould, J.S., Catchpole, W.R., Prediction of fire spread in grasslands Int. J. Wildland Fire, 8, pp. 1-13; Clark, T.L., Jenkins, M.A., Coen, J.L., Packham, D.R., A coupled atmosphere-fire model: Convective feedback on fire line dynamics J. Appl. Meteorol., 35, pp. 875-901; Clark, T.L., Jenkins, M.A., Coen, J.L., Packham, D.R., A coupled atmosphere-fire model: Role of the convective Froude number and dynamic fingering at the fireline Int. J. Wildland Fire, 6, pp. 177-190; Clark, T.L., Griffiths, M., Reeder, M.J., Latham, D., Numerical simulations of grassland fires in the Northern Territory, Australia: A new subgrid-scale fire parameterization J. Geophys. Res., 108 (D18), p. 4589. , doi:10.1029/2002JD003340; Clark, T.L., Coen, J.L., Latham, D., Description of a coupled atmosphere-fire model Int. J. Wildland Fire, 13, pp. 49-63; Cunningham, P., Goodrick, S.L., Hussaini, M.Y., Linn, R.R., Coherent vortical structures in numerical simulations of buoyant plumes from wildland fires Int. J. Wildland Fire, 14, pp. 61-75; Drysdale, D., An Introduction to Fire Dynamics, 2nd Ed., 470p. , John Wiley, Hoboken, N. J; Finney, M.A., FARSITE: Fire area simulator - Model development and evaluation Res. Pap., RMRS-RP-4, 47p. , U.S. Dep. of Agric. For. Serv., Ogden, Utah; Fons, W.T., Analysis of fire spread in light forest fuels J. Agric. Res., 72, pp. 93-121; Grishin, A.M., Mathematical Modeling of Forest Fires and New Methods of Fighting Them, 390p. , edited by F. A. Albini, Tomsk State Univ., Tomsk, Russia; Heilman, W.E., Fast, J.D., Simulations of horizontal roll vortex development above lines of extreme surface heating Int. J. Wildland Fire, 2, pp. 55-68; Larini, M., Giroud, F., Porterie, B., Loraud, J.-C., A multiphase formulation for fire propagation in heterogeneous combustible media Int. J. Heat Mans Transf., 41, pp. 881-897; Linn, R.R., A transport model for prediction of wildfire behavior Sci. Rep., LA-13334-T, 195p. , Los Alamos Natl. Lab., Los Alamos, N. M; Linn, R.R., Harlow, F.H., Mixing-limited transport model used for description of wildfires Computational Technologies for Fluid/Thermal/Structural/Chemical Systems with Industrial Applications, 377 (2), pp. 161-168. , PVP edited by C. R. Kleijn, S. Kawano, and V. V. Kudriavtsev, Am. Soc. of Mech. Eng., New York; Linn, R.R., Reisner, J.M., Colman, J.J., Winterkamp, J., Studying wildfire behavior using FIRETEC Int. J. Wildland Fire, 11, pp. 233-246; Morvan, D., Dupuy, J.-L., Modeling of fire spread through a forest fuel bed using a multiphase formulation Cambust. Flame, 127, pp. 1981-1994; Porterie, B., Morvan, D., Loraud, J.-C., Larini, M., Firespread through fuel beds: Modeling of wind-aided fires and induced hydrodynamics Phys. Fluids, 12, pp. 1762-1782; Rehm, R.G., Evans, D.D., Mell, W.E., Hostikka, S., McGrattan, K.B., Forney, G.P., Bouldin, C., Baker, E., Neighborhood-scale fire spread 5th Symposium on Fire and Forest Meteorology, , paper presented, Am. Meteorol. Soc., Orlando, Fia., 16-20 Nov; Reisner, J.M., Wynne, S., Margolin, L., Linn, R.R., Coupled atmospheric fire modeling employing the method of averages Mon. Weather Rev., 128, pp. 3683-3691; Rothermel, R.C., A mathematical model for predicting fire spread in wildland fuels Res. Pap., INT-115, 40p. , U.S. Dep. of Agric. For. Serv., Ogden, Utah; Sneeuwjagt, R.J., Frandsen, W.H., Behavior of experimental grass fires vs. predictions based on Rothennel's fire model Can. J. For. Res., 7, pp. 357-367; Stephens, G.L., The parameterization of radiation for numerical weather prediction and climate models Mon. Weather Rev., 112, pp. 827-867; Weise, D.R., Modelling Wind and Slope-induced Wildland Fire Behavior, 130p. , Ph.D. dissertation, Univ. of Calif, Berkeley; Wilson, C.C., Sorenson, J.C., Some common denominators of fire behavior on tragedy and near-miss forest fires Publ. NA-GR-8, 31p. , U.S. Dep. of Agric. For. Serv., Broomall, Pa; Wolff, M.F., Carrier, G.F., Fendell, F.E., Wind-aided firespread across arrays of discrete fuel elements. II. Experiment Combust. Sci. Tech., 77, pp. 261-289

PY - 2005/7/16

Y1 - 2005/7/16

N2 - Numerical simulations using a fire model, FIRETEC, coupled to an atmospheric dynamics model, HIGRAD, are examined to investigate several fundamental aspects of fire behavior in grasslands, and specifically the dependence of this behavior on the ambient atmospheric winds and on the initial length of the fire line. The FIRETEC model is based on a multi-phase transport approach, and incorporates representations of the physical processes that govern wildfires, such as combustion and radiative and convective heat exchange. Results from the coupled model show that the forward spread of the simulated fires increases with increasing ambient wind speed, and the spread rates are consistent with those observed in field experiments of grass fires; however, the forward spread also depends significantly on the initial length of the fire line, and for a given ambient wind speed the spread rate for long (100 m) lines is greater than that for short (16 m) lines. The spread of the simulated fires in the lateral direction also depends on the ambient wind speed and the length of the fire line, and a possible explanation for this effect is given. For weak ambient winds, the shape of the fire perimeter is dramatically different from that seen with higher wind speeds. The shape of the fire perimeter is also shown to depend on the initial length of the fire line. These differences in fire behavior are attributed to the differences in the nature of the coupled atmosphere-fire interactions among these cases, and are described in terms of the complex interplay between radiative and convective heat transfer. Copyright 2005 by the American Geophysical Union.

AB - Numerical simulations using a fire model, FIRETEC, coupled to an atmospheric dynamics model, HIGRAD, are examined to investigate several fundamental aspects of fire behavior in grasslands, and specifically the dependence of this behavior on the ambient atmospheric winds and on the initial length of the fire line. The FIRETEC model is based on a multi-phase transport approach, and incorporates representations of the physical processes that govern wildfires, such as combustion and radiative and convective heat exchange. Results from the coupled model show that the forward spread of the simulated fires increases with increasing ambient wind speed, and the spread rates are consistent with those observed in field experiments of grass fires; however, the forward spread also depends significantly on the initial length of the fire line, and for a given ambient wind speed the spread rate for long (100 m) lines is greater than that for short (16 m) lines. The spread of the simulated fires in the lateral direction also depends on the ambient wind speed and the length of the fire line, and a possible explanation for this effect is given. For weak ambient winds, the shape of the fire perimeter is dramatically different from that seen with higher wind speeds. The shape of the fire perimeter is also shown to depend on the initial length of the fire line. These differences in fire behavior are attributed to the differences in the nature of the coupled atmosphere-fire interactions among these cases, and are described in terms of the complex interplay between radiative and convective heat transfer. Copyright 2005 by the American Geophysical Union.

KW - Computer simulation

KW - Fires

KW - Heat convection

KW - Mathematical models

KW - Numerical analysis

KW - Wind effects

KW - atmospheric modeling

KW - combustion

KW - grassland

KW - heat transfer

KW - numerical method

KW - radiative forcing

KW - thermal convection

KW - wildfire

KW - wind velocity

U2 - 10.1029/2004JD005597

DO - 10.1029/2004JD005597

M3 - Article

VL - 110

JO - Journal of Geophysical Research: Atmospheres

JF - Journal of Geophysical Research: Atmospheres

SN - 2169-897X

IS - 13

ER -