Pyroconvective interactions and spot fire dynamics

Hazard Note 61 details pioneering research that is developing the first, two-dimensional fire simulation model that can operate in faster than real time, while incorporating intrinsic, fire line dynamics.

Fires that burn in close proximity can influence each other due to pyroconvective interactions between individual fires. The same processes can apply to different parts of a single fire line. A typical example is when intense spotting causes many fires to form and coalesce. Interactions between individual spot fires and other parts of the main fire perimeter can increase local rates of spread, in unexpected directions, potentially producing broad, flaming zones that can entrap firefighters, and increase the likelihood of extreme bushfires.

By combining advanced mathematical modelling with laboratory and numerical experimentation, this research is providing insights into the physical drivers of these interactions. In particular, it elevates the critical role of pyroconvective interactions in many aspects of fire propagation.

These findings are the basis of computationally efficient modelling techniques that enable pyroconvective effects and dynamic fire behaviours to be included in two-dimensional, fire spread simulators. More cost-effective than current simulators, they could ultimately help protect firefighters, communities at risk and property.

Further reading

Hilton JE, Sullivan AL, Swedosh W, Sharples JJ & Thomas CM, (2018) Incorporating convective feedback in wildfire simulations using pyrogenic potential, Environmental Modelling and Software, 107:12-24

Hilton JE, Sharples, JJ, Sullivan AL & Swedosh W, (2017) Simulation of spot fire coalescence with dynamic feedback, in 22nd International Congress on Modelling and Simulation, Hobart, Tasmania, Australia

Next generation fire modelling, (2016), Bushfire and Natural Hazards CRC Hazard Note 21

Sullivan AL, Cruz M, Ellis P, Gould J & Pluinski M, (2014), Fire cycle insights aid in bushfire battle, Bushfire CRC Fire Note 127

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