Slope effect on junction fire with two non-symmetric fire fronts
Carlos Ribeiro
A * , Domingos Xavier Viegas A , Jorge Raposo A , Luís Reis A and Jason Sharples B C
+ Author Affiliations
- Author Affiliations
A Univ Coimbra, ADAI, Department of Mechanical Engineering, Rua Luís Reis Santos, Pólo II, 3030‐788 Coimbra, Portugal.
B School of Science, University of New South Wales (UNSW), Canberra, ACT, Australia.
C Bushfire and Natural Hazards Cooperative Research Centre, East Melbourne, Vic., Australia.
* Correspondence to: carlos.ribeiro@adai.pt
International Journal of Wildland Fire 32(3) 328-335 https://doi.org/10.1071/WF22152
Submitted: 13 July 2022 Accepted: 18 December 2022 Published: 23 January 2023
© 2023 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of IAWF. This is an open access article distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND)
Abstract
Background: In Pedrógão Grande on 17 June 2017, two fire fronts merged and the propagation of the fire was influenced by the interaction of these non-symmetric fire fronts.
Aims: This wildfire motivated us to study a junction fire with two non-symmetrical fire fronts. The analysis of the movement of the intersection point and the angle (γ) between the bisector of the fire lines and the maximum rate of spread (ROS) direction is of particular relevance.
Methods: The study was carried out at Forest Fire Laboratory of the University of Coimbra in Lousã (Portugal) with laboratory experiments.
Key results: We found that, for small rotation angles (δ), the non-dimensional ROS of the intersection point depends on the slope angle (α) and the initial angle between fire fronts.
Conclusions: For high α, the non-dimensional ROS was highly influenced by the convection process and γ where the maximum ROS occurred, increased when δ increased. However, the radiation process was more relevant for lower α and influenced the non-dimensional ROS. For these cases, the maximum spread direction was close to that of the fire line bisector.
Implications: The present work aimed to explain fire behaviour during the Pedrógão Grande wildfire.
Keywords: convergent fire fronts, dynamic fire behaviour, extreme fire behaviour, fire acceleration, fire behaviour, fire growth, fire modelling, forest fires, junction fires, merging fires.
References
Andrade C (2019) The P Value and Statistical Significance: Misunderstandings, Explanations, Challenges, and Alternatives. Indian Journal of Psychological Medicine 41, 210–215.| The P Value and Statistical Significance: Misunderstandings, Explanations, Challenges, and Alternatives.Crossref | GoogleScholarGoogle Scholar |
Brown AA, Davis K (1973) ‘Forest Fire: Control and Use.’ (McGraw-Hill: New York)
Devore JL (2010) ‘Probability and Statistics for Engineering and the Sciences’, 8th edn. (Ed. M Julet) (Brooks/Cole, Cengage Learning: Boston, MA, USA)
Dlugogorski BZ, Hirunpraditkoon S, Kennedy EM (2014) Ignition temperature and surface emissivity of heterogeneous loosely packed materials from pyrometric measurements. Fire Safety Science 11, 262–275.
| Ignition temperature and surface emissivity of heterogeneous loosely packed materials from pyrometric measurements.Crossref | GoogleScholarGoogle Scholar |
Doogan M (2006) ‘The Canberra Firestorm. Inquests and Inquiry into Four Deaths and Four Fires between 8 and 18 January 2003.’ (ACT Coroner’s Court: Canberra, ACT)
Filipe dos Santos Viana H, Martins Rodrigues A, Godina R, Carlos de Oliveira Matias J, Jorge Ribeiro Nunes L (2018) Evaluation of the physical, chemical and thermal properties of Portuguese maritime pine biomass. Sustainability 10, 2877
| Evaluation of the physical, chemical and thermal properties of Portuguese maritime pine biomass.Crossref | GoogleScholarGoogle Scholar |
Filkov A, Cirulis B, Penman T (2021) Quantifying merging fire behaviour phenomena using unmanned aerial vehicle technology. International Journal of Wildland Fire 30, 197–214.
| Quantifying merging fire behaviour phenomena using unmanned aerial vehicle technology.Crossref | GoogleScholarGoogle Scholar |
Hilton JE, Miller C, Sharples JJ, Sullivan AL (2016) Curvature effects in the dynamic propagation of wildfires. International Journal of Wildland Fire 25, 1238–1251.
| Curvature effects in the dynamic propagation of wildfires.Crossref | GoogleScholarGoogle Scholar |
Johansen RW (1984) Prescribed Burning with Spot Fires in the Georgia Coastal Plain. Georgia Forestry Commission 49, 1–8. Available at http://www.treesearch.fs.fed.us/pubs/36481
Liu N, Wu J, Chen H, Zhang L, Deng Z, Satoh K, Viegas DX, Raposo JR (2015) Upslope spread of a linear flame front over a pine needle fuel bed: The role of convection cooling. Proceedings of the Combustion Institute 35, 2691–2698.
| Upslope spread of a linear flame front over a pine needle fuel bed: The role of convection cooling.Crossref | GoogleScholarGoogle Scholar |
Pastor E, Zárate L, Planas E, Arnaldos J (2003) Mathematical models and calculation systems for the study of wildland fire behaviour. Progress in Energy and Combustion Science 29, 139–153.
| Mathematical models and calculation systems for the study of wildland fire behaviour.Crossref | GoogleScholarGoogle Scholar |
Pinto P, Silva ÁP, Viegas DX, Almeida M, Raposo J, Ribeiro LM (2022) Influence of Convectively Driven Flows in the Course of a Large Fire in Portugal: The Case of Pedrógão Grande. Atmosphere 13, 414
| Influence of Convectively Driven Flows in the Course of a Large Fire in Portugal: The Case of Pedrógão Grande.Crossref | GoogleScholarGoogle Scholar |
Pyne SJ (1984) ‘Introduction to wildland fire: Fire Management in the United States.’ (John Wiley and Sons: New York)
Raposo JRN (2016) Extreme Fire Behaviour Associated with the Merging of Two Linear Fire Fronts. PhD Thesis, Department of Mechanical Engineering of the Faculty of Science and Technology, University of Coimbra. Available at http://hdl.handle.net/10316/31020
Raposo JR, Cabiddu S, Viegas DX, Salis M, Sharples J (2015) Experimental analysis of fire spread across a two-dimensional ridge under wind conditions. International Journal of Wildland Fire 24, 1008–1022.
| Experimental analysis of fire spread across a two-dimensional ridge under wind conditions.Crossref | GoogleScholarGoogle Scholar |
Raposo JR, Viegas DX, Xie X, Almeida M, Figueiredo AR, Porto L, Sharples J (2018) Analysis of the physical processes associated with junction fires at laboratory and field scales. International Journal of Wildland Fire 27, 52–68.
| Analysis of the physical processes associated with junction fires at laboratory and field scales.Crossref | GoogleScholarGoogle Scholar |
Rodrigues A, Ribeiro C, Raposo J, Viegas DX, André J (2019) Effect of canyons on a fire propagating laterally over slopes. Frontiers in Mechanical Engineering 5, 402–409.
| Effect of canyons on a fire propagating laterally over slopes.Crossref | GoogleScholarGoogle Scholar |
Sharples JJ, Towers IN, Wheeler G, Wheeler V-M, Mccoy JA (2013) Modelling fire line merging using plane curvature flow. In ‘MODSIM2013, 20th International Congress on Modelling and Simulation’. (Eds J Piantadosi, RS Anderssen, J Boland) pp. 256–262. Available at
| Crossref |
Sullivan AL (2009) Wildland surface fire spread modelling, 1990–2007. 3: Simulation and mathematical analogue models. International Journal of Wildland Fire 18, 387–403.
| Wildland surface fire spread modelling, 1990–2007. 3: Simulation and mathematical analogue models.Crossref | GoogleScholarGoogle Scholar |
Sullivan AL, Swedosh W, Hurley RJ, Sharples JJ, Hilton JE (2019) Investigation of the effects of interactions of intersecting oblique fire lines with and without wind in a combustion wind tunnel. International Journal of Wildland Fire 28, 704–719.
| Investigation of the effects of interactions of intersecting oblique fire lines with and without wind in a combustion wind tunnel.Crossref | GoogleScholarGoogle Scholar |
Thomas CM, Sharples JJ, Evans JP (2015) Pyroconvective interaction of two merged fire lines: curvature effects and dynamic fire spread. In ‘MODSIM2015, 21st International Congress on Modelling and Simulation’. (Eds T Weber, MJ McPhee, RS Anderssen) pp. 312–318. Available at
| Crossref |
Thomas CM, Sharples JJ, Evans JP (2017) Modelling the dynamic behaviour of junction fires with a coupled atmosphere-fire model. International Journal of Wildland Fire 26, 331–344.
| Modelling the dynamic behaviour of junction fires with a coupled atmosphere-fire model.Crossref | GoogleScholarGoogle Scholar |
Viegas DX (2006) Parametric study of an eruptive fire behaviour model. International Journal of Wildland Fire 15, 169–177.
| Parametric study of an eruptive fire behaviour model.Crossref | GoogleScholarGoogle Scholar |
Viegas DX, Pita LP (2004) Fire spread in canyons. International Journal of Wildland Fire 13, 253–274.
| Fire spread in canyons.Crossref | GoogleScholarGoogle Scholar |
Viegas DX, Raposo JR, Davim DA, Rossa CG (2012) Study of the jump fire produced by the interaction of two oblique fire fronts. Part 1. Analytical model and validation with no-slope laboratory experiments. International Journal of Wildland Fire 21, 843–856.
| Study of the jump fire produced by the interaction of two oblique fire fronts. Part 1. Analytical model and validation with no-slope laboratory experiments.Crossref | GoogleScholarGoogle Scholar |
Viegas D, Raposo J, Figueiredo A (2013) Preliminary analysis of slope and fuel bed effect on jump behavior in forest fires. Procedia Engineering 62, 1032–1039.
| Preliminary analysis of slope and fuel bed effect on jump behavior in forest fires.Crossref | GoogleScholarGoogle Scholar |
Viegas DXFC, Raposo JRN, Ribeiro CFM, Reis LCD, Abouali A, Viegas CXP (2021) On the non-monotonic behaviour of fire spread. International Journal of Wildland Fire 30, 702–719.
| On the non-monotonic behaviour of fire spread.Crossref | GoogleScholarGoogle Scholar |
Viegas DXFC, Raposo JRN, Ribeiro CFM, Reis L, Abouali A, Ribeiro LM, Viegas CXP (2022) On the intermittent nature of forest fire spread – Part 2. International Journal of Wildland Fire 31, 967–981.
| On the intermittent nature of forest fire spread – Part 2.Crossref | GoogleScholarGoogle Scholar |
Viegas DX (2004) A Mathematical Model For Forest Fires Blowup. Combustion Science and Technology 177, 27–51.
| A Mathematical Model For Forest Fires Blowup.Crossref | GoogleScholarGoogle Scholar |
Xie X, Liu N, Viegas DX, Raposo JR (2014) Experimental Research on Upslope Fire and Jump Fire. Fire Safety Science 11, 1430–1442.
| Experimental Research on Upslope Fire and Jump Fire.Crossref | GoogleScholarGoogle Scholar |
