OPEN ACCESS
An analysis was conducted on when aerial suppression through direct attack using a helicopter could be ineffective due to a high heat release rate of the wildfire. The analysis consisted of a numerical estimate and where the results were compared with existing operational thresholds on aerial wildfire suppression. It was found that up to a heat release rate of 10000 kW, practically all droplet paths effectively penetrated the plume region. At heat release rates of 12500 and 23000 kW, only the path at an angle to the centreline effectively penetrated the plume region. The calculated results of the analysis were compared with suppression thresholds and found to correspond well in the vertical trajectory case. The findings of the paper could serve as starting point for the development of decision support for aerial wildfire suppression.
aerial, fire suppression, plume, water, wildfire.
[1] Plucinski, M., Gould, J., McCarthy, G. & Hollis, J., The Effectiveness and Efficiency of Aerial Firefighting in Australia, Part 1. Bushfire CRC Technical Report Number A0701, 2007.
[2] Andersen, W.H., Brown, R.E., Kato, K.G. & Louie, N.A., Investigation of Rheological Properties of Aerial-Delivered Fire Retardant – Final Report. USDA Forest Service, Intermountain Research Station, Report 8990–04, 1974.
[3] Andersen, W.H., Brown, R.E., Louie, N.A., Blatz, P.J. & Burchfield, J.A., Investigation of Rheological Properties of Aerial-Delivered Fire Retardant Extended Study – Final Report. USDA Forest Service, Intermountain Research Station, Report 8990–05, 1974.
[4] Andersen, W.H., Brown, R.E., Louie, N.A., Kato, K.G., Burchfield, J.A., Dalby, J.D. & Zernow, L., Correlation of Rheological Properties of Liquid Fire Retardant With Aerially Delivered Performance – Final Report. USDA Forest Service, Intermountain Research Station, Report 8990–08, 1976.
[5] George, C.W. & Blakely, A.D., An Evaluation of The Drop Characteristics and Ground Distribution Patterns Of Forest Fire Retardants. Research paper INT-134, USDA Forest Service, Ogden, 1973.
[6] Stechishen, E., CL-215 Air Tanker Modifications Improve Drop Pattern. Information report FF-X-61, Forest Fire Institute, Ottawa, 1976.
[7] Swanson, D.H., & Helvig, T.N., High-altitude retardant drop mechanization study. Honeywell Inc., Government and Aeronautical Products Division, Final Report, vol. 1, contract 26–2888, 1973.
[8] Swanson, D.H., & Helvig, T.N., Extended high-altitude retardant drop mechanization study. Honeywell Inc., Government and Aeronautical Products Division, Final Report, contract 26–2888, 1974.
[9] Swanson, D.H., Luedecke, A.D., Helvig, T.N. & Parduhn, F.J., Development of User Guidelines for Selected Retardant Aircraft. Final report, contract 26–3332. Honeywell Inc., Government and Aeronautical Products Division, 1975.
[10] Swanson, D.H., Luedecke, A.D., Helvig, T.N. & Parduhn, F.J., Supplement to Development of User Guidelines for Selected Retardant Aircraft. Honeywell Inc., Government and Aeronautical Products Division, Final report, contract 26–3332, 1977.
[11] Swanson, D.H., Luedecke, A.D. & Helvig, T.N., Experimental Tank and Gating System (ETAGS). Honeywell Inc., Government and Aeronautical Products Division, Final report, contract 26–3425, 1978.
[12] Newstead, R.G. & Lieskovsky, R.J., Air Tanker and Fire Retardant Drop Patterns. Northern Forest Research Centre, Canadian Forestry Service, Edmonton, 1985.
[13] Amorim, J.H., Numerical modelling of the aerial drop of firefighting agents by fixedwing aircraft. Part I: model development. Int J of Wildland Fire, 20, pp. 384–393, 2011. https://doi.org/10.1071/wf09122
[14] Hansen, R., Estimating the amount of water required to extinguish wildfires under different conditions and in various fuel types. Int J of Wildland Fire, 21, pp. 525–536, 2012. https://doi.org/10.1071/wf11022
[15] Penney, G., Habibi, D., Cattani, M. & Carter, M., Calculation of critical water flow rates for wildfire suppression. Fire 2019, 2, 3; doi:10.3390/fire2010003.
[16] Plucinski, M.P., Fighting flames and forging firelines: wildfire suppression effectiveness at the fire edge. Current Forestry Reports, 5, pp. 1–19, 2019. https://doi.org/10.1007/s40725-019-00084-5
[17] Baum, H.R. & McCaffrey, B.J., Fire induced flow field – theory and experiment. Fire Safety Science – Proceedings of the Second International Symposium, Tokyo, Japan, pp. 129–148, 1989.
[18] Tihay, V., Santoni P-A., Simeoni A., Garo J-P. & Vantelon J-P., Skeletal and global mechanisms for the combustion of gases released by crushed forest fuels. Combust Flame, 156, pp. 1565–1575, 2009. https://doi.org/10.1016/j.combustflame.2009.05.004
[19] Heskestad, G., Fire plumes, flame heights, and air entrainment. In The SFPE Handbook of Fire Protection Engineering, fourth edition (eds: DiNenno P.J. et al.); NFPA, Quincy, 2008.
[20] McCaffrey, B.J., Purely buoyant diffusion flames: Some experimental results, national bureau of standards, NBSIR 79–1910, 1979.304 R. Hansen, Int. J. of Safety and Security Eng., Vol. 9, No. 4 (2019)
[21] Boysan, F., Ayers, W.H., Swithenbank, J., Pan Z., Three-Dimensional Model of Spray Combustion in Gas Turbine Combustors. Journal of Energy, 6, pp. 368–375, 1982. https://doi.org/10.2514/3.62618
[22] Link, E.D., The interaction of sprinkler sprays and fire plumes. Dissertation, University of Maryland, College Park, 2017.
[23] Van Meter, W.P., & George, C.W., Correlating laboratory air drop data with retardant rheological properties. Research Paper INT-278, USDA, Ogden, 1981.
[24] Jain, M., Prakash, R.S., Tomar, G. & Ravikrishna, R.V., Secondary breakup of a drop at moderate Weber numbers. Proc R Soc Lond, 471, 20140930, 2015. https://doi.org/10.1098/rspa.2014.0930
[25] Beyler, C.L., The interaction of fire and sprinklers. NBS GCR 77–105, National Bureau of Standards, Washington, DC, 1977.
[26] Hsiang, L.P. & Faeth, G.M., Near-limit drop deformation and secondary breakup. Int J Multiphase Flow, 18, pp. 635–652, 1992. https://doi.org/10.1016/0301-9322(92)90036-g
[27] Turns, S.R., An Introduction to Combustion: Concepts and Applications, 2nd ed., McGraw-Hill, Singapore, 2000.
[28] Tamimi, A., Rinker, E.B. & Sandall, O.C., Diffusion coefficients for hydrogen sulphide, carbon dioxide, and nitrous oxide in water over the temperature range 293–368 K. J Chem Eng Data, 39, pp. 330–332, 1994. https://doi.org/10.1021/je00014a031
[29] Andrews, P.L. & Rothermel, R.C., Charts for interpreting wildland fire behavior characteristics. General Technical Report INT-131, USDA, Ogden, 1982.
[30] Loane, I.T. & Gould, J.S., Aerial suppression of bushfires: cost-benefit study for Victoria. National Bushfire Research Unit, CSIRO Division of Forest Research, Canberra, 1986.
[31] Thomas, P.H., The size of flames from natural fires. Proceedings of the 9th International Symposium on Combustion, Ithaca, USA, 27 August–1 September 1963; The Combustion Institute: Pittsburgh, PA; pp. 844–859, 1963.
[32] Van Meter, W.P., Using Rheology to estimate short-term retardant droplet sizes. research Note INT-327, USDA, Ogden, 1983.
[33] Gould, J.S., Knight, I. & Sullivan, A.L., Physical Modelling of Leaf Scorch Height from Prescribed Fires in Young Eucalyptus sieberi Regrowth Forests in South-eastern Australia. Int J of Wildland Fire, 7, pp. 7–20, 1997. https://doi.org/10.1071/wf9970007