Book contents
- Wildland Fire Dynamics
- Wildland Fire Dynamics
- Copyright page
- Contents
- Contributors
- 1 Wildland Fire Combustion Dynamics
- 2 The Structure of Line Fires at Flame Scale
- 3 Energy Transport and Measurements in Wildland and Prescribed Fires
- 4 Fire Line Geometry and Pyroconvective Dynamics
- 5 Firebrands
- 6 Re-envisioning Fire and Vegetation Feedbacks
- 7 Wind and Canopies
- 8 Coupled Fire–Atmosphere Model Evaluation and Challenges
- Index
- References
2 - The Structure of Line Fires at Flame Scale
Published online by Cambridge University Press: 16 June 2022
Book contents
- Wildland Fire Dynamics
- Wildland Fire Dynamics
- Copyright page
- Contents
- Contributors
- 1 Wildland Fire Combustion Dynamics
- 2 The Structure of Line Fires at Flame Scale
- 3 Energy Transport and Measurements in Wildland and Prescribed Fires
- 4 Fire Line Geometry and Pyroconvective Dynamics
- 5 Firebrands
- 6 Re-envisioning Fire and Vegetation Feedbacks
- 7 Wind and Canopies
- 8 Coupled Fire–Atmosphere Model Evaluation and Challenges
- Index
- References
Summary
We present a discussion of the structure of line fires, a canonical configuration in wildland fire research. This configuration allows detailed studies of the effects of wind and sloped terrain on heat transfer and fire spread mechanisms at flame scale. We emphasize in the discussion the existence of two limiting flame regimes in line fires: the plume-dominated regime, in which the flame is detached from the ground, and the wind or slope-driven regime, in which the flame is attached to that surface. These two regimes correspond to dramatically different flame structures, flow patterns, modes of heat transfer, and flame spread mechanisms. The transition between the two flame regimes is discussed in terms of critical values of Byram's convection number or slope angle. We limit our discussion to a simplified configuration corresponding to gas-fueled flames. Hence the heat release rate of the flame is controlled and the flame is non-spreading; difficulties associated with real wildland fuel are left out of the discussion. The structure of the line fires is discussed through results from high-resolution simulations of laboratory-scale flames based on a large eddy simulation (LES) approach. Additional insight is also obtained through a scaling analysis based on an integral model.
Keywords
- Type
- Chapter
- Information
- Wildland Fire DynamicsFire Effects and Behavior from a Fluid Dynamics Perspective, pp. 35 - 62Publisher: Cambridge University PressPrint publication year: 2022
References
Albini, FA (1981) A model for the wind-blown flame from a line fire. Combustion and Flame 43, 155–174.CrossRefGoogle Scholar
Canfield, JM, Linn, RR, Sauer, JA, Finney, M, Forthofer, J (2014) A numerical investigation of the interplay between fireline length, geometry, and rate of spread. Agricultural and Forest Meteorology 189 –190, 48–49.Google Scholar
Chai, J, Patanka, S (2006) Discrete-ordinates and finite-volume methods for radiation heat transfer. In: Minkowycz, WJ, Sparrow, EM, Murthy, JY, eds. Handbook of Numerical Heat Transfer. Hoboken, NJ: John Wiley & Sons, pp. 297–323.Google Scholar
Clark, TL, Coen, J, Latham, D (2004) Description of a coupled atmosphere–fire model. International Journal of Wildland Fire 13(1), 49–64.CrossRefGoogle Scholar
Coen, JL, Cameron, M, Michalakes, J, Patton, EG, Riggan, PJ, Yedinak, KM. (2013) Wrf-fire: Coupled weather–wildland fire modeling with the weather research and forecasting model. Journal of Applied Meteorology and Climatology 52(1), 16–38.CrossRefGoogle Scholar
Dold, JW, Zinoviev, A (2009) Fire eruption through intensity and spread rate interaction mediated by flow attachment. Combustion Theory and Modelling 13(5), 763–793.CrossRefGoogle Scholar
Drysdale, DD, Macmillan, AJR (1992) Flame spread on inclined surfaces. Fire Safety Journal 18, 245–254.CrossRefGoogle Scholar
Dupuy, J-L, Maréchal, J (2011) Slope effect on laboratory fire spread: Contribution of radiation and convection to fuel bed preheating. International Journal of Wildland Fire 20(2), 289–307.CrossRefGoogle Scholar
Dupuy, J-L, Maréchal, J, Portier, D, Valette, J-C (2011) The effects of slope and fuel bed width on laboratory fire behaviour. International Journal of Wildland Fire 20(2), 272–288.Google Scholar
Escudier, MP (1972) Aerodynamics of a burning turbulent gas jet in a crossflow. Combustion Science and Technology 4(1), 293–301.CrossRefGoogle Scholar
Escudier, MP (1975) Analysis and observations of inclined turbulent flame plumes. Combustion Science and Technology 10(3–4), 163–171.Google Scholar
Filippi, JB, Bosseur, F, Mari, C, Lac, C, Moigne, PL, Cuenot, B, Veynante, D, Cariolle, D, Balbi, J (2009) Coupled atmosphere–wildland fire modelling. Journal of Advances in Modeling Earth Systems 1(4), 11.Google Scholar
Filippi, JB, Pialat, X, Clements, CB (2013) Assesment of forefire/meso-nh for wildland fire/atmosphere coupled simulation of the fireflux experiment. Proceedings of the Combustion Institute 34(2), 2633–2640.Google Scholar
Finney, MA, Cohen, JD, Forthofer, JM, McAllister, SS, Gollner, MJ, Gorham, DJ, Saito, K, Akafuah, NK, Adam, BA, English, JD. (2015) Role of buoyant flame dynamics in wildfire spread. Proceedings of the National Academy of Sciences (USA) 112(32), 9833–9838.CrossRefGoogle ScholarPubMed
Finney, MA, Cohen, JD, McAllister, SS, Jolly, WM (2013) On the need for a theory of wildland fire spread. International Journal of Wildland Fire 22(1), 25–36.Google Scholar
Fureby, C, Tabor, G, Weller, HG, Gosman, AD (1997) A comparative study of subgrid scale models in homogeneous isotropic turbulence. Physics of Fluids 9(5), 1416–1429.Google Scholar
Hoult, DP, Fay, JA, Forney, LJ (1969) A theory of plume rise compared with field observations. Journal of the Air Pollution Control Association 19(8), 585–590.Google Scholar
Hu, L (2017) A review of physics and correlations of pool fire behaviour in wind and future challenges. Fire Safety Journal 91, 41–55.Google Scholar
Huang, X, Gollner, MJ (2014) Correlations for evaluation of flame spread over an inclined surface. Proceedings of the Eleventh International Symposium, International Association for Fire Safety Science (IAFSS) 13, 222–233.Google Scholar
Kochanski, AK, Jenkins, MA, Mandel, J, Beezley, JD, Clements, CB, Krueger, S (2013) Evaluation of wrf-sfire performance with field observations from the fireflux experiment. Geoscientific Model Development 6(4), 1109–1126.CrossRefGoogle Scholar
Krishnamurthy, R, Hall, JD (1987) Numerical and approximate solutions for plume rise. Atmospheric Environment 21(10), 2083–2089.Google Scholar
Lam, CS, Weckman, EJ (2015a) Wind-blown pool fire, Part I: Experimental characterization of the thermal field. Fire Safety Journal 75, 1–13.CrossRefGoogle Scholar
Lam, CS, Weckman, EJ (2015b) Wind-blown pool fire, Part II: Comparison of measured flame geometry with semi-empirical correlations. Fire Safety Journal 78, 130–141.Google Scholar
Linn, RR, Cunningham, P (2005) Numerical simulations of grass fires using a coupled atmosphere-fire model: Basic fire behavior and dependence on wind speed. Journal of Geophysical Research 110, D13107.Google Scholar
Magnussen, BF, Hjertager, BH (1976) On mathematical modeling of turbulent combustion with special emphasis on soot formation and combustion. Symposium (International) on Combustion 16(1), 719–729.Google Scholar
Mandel, J, Beezley, JD, Kochanski, AK (2011) Coupled atmosphere–wildland fire modeling with wrf 3.3 and sfire 2011. Geoscientific Model Development 4(3), 591–610.Google Scholar
Mell, W, Jenkins, MA, Gould, J, Cheney, P (2007) A physics-based approach to modeling grassland fires. International Journal of Wildland Fire 16(1), 1–22.CrossRefGoogle Scholar
Mercer, GN, Weber, RO (1994) Plumes above line fires in a cross wind. International Journal of Wildland Fire 4(4), 201–207.Google Scholar
Morandini, F, Silvani, X (2010) Experimental investigation of the physical mechanisms governing the spread of wildfires. International Journal of Wildland Fire 19(5), 570–582.Google Scholar
Morandini, F, Silvani, X, Dupuy, J-L, Susset, A (2018) Fire spread across a sloping fuel bed: Flame dynamics and heat transfers. Combustion and Flame 190, 158–170.Google Scholar
Morvan, D (2011) Physical phenomena and length scales governing the behavior of wildfires: A case for physical modelling. Fire Technology 47(2), 437–460.Google Scholar
Morvan, D, Dupuy, JL (2001) Modeling of fire spread through a forest fuel bed using a multiphase formulation. Combustion and Flame 127(1–2), 1981–1994.Google Scholar
Morvan, D, Dupuy, JL (2004) Modeling the propagation of a wildfire through a mediterranean shrub using a multiphase formulation, Combustion and Flame 138(3), 199–210.Google Scholar
Morvan, D, Frangieh, N (2008) Wildland fires behavior: Wind effect versus Byram’s convective number and consequences upon the regime of propagation. International Journal of Wildland Fire 27(9), 636–641.CrossRefGoogle Scholar
Morvan, D, Porterie, B, Larini, M, Loraud, JC. (1998) Numerical simulation of turbulent diffusion flame in cross flow. Combustion Science and Technology 140(1–6), 93–122.Google Scholar
Nelson, RM (1993) Byram’s derivation of the energy criterion for forest and wildland fires. International Journal of Wildland Fire 3(3), 131–138.Google Scholar
Nelson, RM (2002) An effective wind speed for models of fire spread. International Journal of Wildland Fire 11(2), 153–161.Google Scholar
Nelson, RM (2015) Re-analysis of wind and slope effects on flame characteristics of Mediterranean shrub fires. International Journal of Wildland Fire 24(7), 1001–1007.CrossRefGoogle Scholar
Nelson, RM, Butler, BW, Weise, DR (2012) Entrainment regimes and flame characteristics of wildland fires. International Journal of Wildland Fire 21(2), 127–140.CrossRefGoogle Scholar
Nicoud, F, Ducros, F (1999) Subgrid-scale stress modelling based on the square of the velocity gradient tensor. Flow, Turbulence and Combustion 62(3), 183–200.Google Scholar
Nmira, F, Consalvi, JL, Boulet, P, Porterie, B (2010) Numerical study of wind effects on the characteristics of flames from non-propagating vegetation fires. Fire Safety Journal 45(2), 129–141.CrossRefGoogle Scholar
Pagni, PJ, Peterson, TG (1973) Flame spread through porous fuels. Symposium (International) on Combustion 14(1), 1099–1107.Google Scholar
Piomelli, U, Balaras, E (2002) Wall-layer models for large-eddy simulations. Annual Review of Fluid Mechanics 34, 349–374.Google Scholar
Porterie, B, Morvan, D, Loraud, JC, Larini, M (2000) Firespread through fuel beds: Modeling of wind-aided fires and induced hydrodynamics. Physics of Fluids 12(7), 1762–1782.Google Scholar
Putnam, AA (1965) A model study of wind-blown free-burning fires. Symposium (International) on Combustion 10(1), 1039–1046.Google Scholar
Raupach, MR (1990) Similarity analysis of the interactions of bushfire plumes with ambient winds. Mathematical and Computer Modelling 13(12), 113–121.CrossRefGoogle Scholar
Ren, N, Wang, Y, Vilfayeau, S, Trouvé, A (2016) Large eddy simulation of turbulent vertical wall fires supplied with gaseous fuel through porous burners. Combustion and Flame 169(3), 194–208.Google Scholar
Sharples, JJ, Gill, AM, Dold, JW (2010) The trench effect and eruptive wildfires: Lessons from the King’s Cross underground disaster. Proceedings of the Australasian Fire and Emergency Service Authorities Council (AFAC) Conference, September, Darwin.Google Scholar
Smith, DA (1992) Measurements of flame length and flame angle in an inclined trench. Fire Safety Journal 18(3), 231–244.CrossRefGoogle Scholar
Sullivan, AL (2007) Convective froude number and Byram’s energy criterion of Australian experimental grassland fires. Proceedings of the Combustion Institute 31(2), 2557–2564.Google Scholar
Tang, W, Miller, CH, Gollner, MJ (2017) Local flame attachment and heat fluxes in wind-driven line fires. Proceedings of the Combustion Institute 36(2), 3253–3261.Google Scholar
Viegas, DX (2004) On the existence of a steady state regime for slope and wind driven fires. International Journal of Wildland Fire 13(1), 101–117.Google Scholar
Viegas, DX (2005) A mathematical model for forest fires blowup. Combustion Science and Technology 177(1), 27–51.Google Scholar
Vilfayeau, S, White, JP, Sunderland, PB, Marshall, AW, Trouvé, A (2016) Large eddy simulation of flame extinction in a turbulent line fire exposed to air–nitrogen co-flow. Fire Safety Journal 86, 16–31.Google Scholar
Woodburn, PJ, Drysdale, DD (1998) Fires in inclined trenches: The dependence of the critical angle on the trench and burner geometry. Fire Safety Journal 31, 143–164.CrossRefGoogle Scholar
Wu, Y, Xing, HJ, Atkinson, G (2000) Interaction of fire plume with inclined surface. Fire Safety Journal 35(4), 391–403.CrossRefGoogle Scholar
Yuan, L-M, Cox, G (1996) An experimental study of some line fires. Fire Safety Journal 27(2), 123–139.Google Scholar