Ronan Paugam,
Researcher, Universitat Politecnica de Catalunya,
Barcelona, Catalunya, ES

"Airborne Observation from Experimental Fire: fire behavior metrics, plume simulation and synthetic IR image modelling"

Apr 19, 2023, Schedule:

Nespresso & Teatime 417 DSL - Commons

 

03:00 to 03:30 PM Eastern Time (US and Canada)

Colloquium - F2F  499 DSL / Virtual Zoom

 

03:30 to 04:30 PM Eastern Time (US and Canada)

Abstract:

Coupled fire-atmosphere systems are currently developed to respond to the need for operational systems in air quality and fire attack management. This presentation shows how Infra-Red airborne observation can be used to support this goal.

Using experimental fire of several hectares conducted in savanna type vegetation, IR images are collected both from a Middle Infra-Red (MIR) and Long Wave Infra-Red (LWIR) camera operated from hovering helicopter. Images are then postprocessed including orthorectification of images time series and fire front segmentation. Finally, fire behaviors metrics are extracted. Maps of fire intensity, Rate of Spread and Fire Radiative Power (FRP) at 1m spatial resolution and 1Hz are presented for 4 experimental burns ranging from 4 to 8 ha.

Using this fire behavior metrics and assumption on radiative/convective fraction, convective heat released are computed at a resolution of 2m. Using the so-called burner method that we implement in the MesoNH-ForeFire model, the plume dynamics is simulated over the duration of the whole fire progression. Such an approach can provide reference test cases for more complex coupled fire-atmosphere simulation. First sensitivity study on the effect of the cooling area on the plume dynamics is then discussed.

Finally, the presentation shows recent work on radiative transfer simulation in the context of fire scene based on the DART model. This supports an effort to develop an end-to-end simulation strategy capable of linking fire simulated scene and direct observable such as IR images. Using FDS simulation of grass land fire coupled with DART, we simulate synthetic IR ground and airborne MIR images. This development aims at better understanding active fire monitoring, in particular the effect of flames and plume geometry on the FRP computation.