Parametric evaluation of heat transfer mechanisms in a WUI fire scenario

Background. Wildland-urban interface (WUI) fires are becoming more frequent and catastrophic as they are associated with the effects of climate change, demographic pressure, human activities, abandonment of rural areas and activities promoting dangerous fuel continuity. For example, in the central regions of Portugal, Chile and California, severe direct and indirect impacts have been observed, with a catastrophic number of fatalities. Aims. Mitigating and reducing the impacts of wildfires in the WUI requires understanding heat transfer mechanisms from forest fires and understanding how structures ignite is crucial to define and implement new mitigation strategies. Methods. Adopting Computational Fluid Dynamics is essential to assess the WUI fire problem by simulating fire behaviour and quantifying its characteristics. In this paper, a building is exposed to several wildfire scenarios, assessing the influence of parameters such as materials, fuels, topography and meteorological conditions. Key results. The investigated scenarios were developed considering validated Fire Dynamics Simulator (FDS) models of single trees on fire and the influence of governing parameters was quantified. Conclusions. For the selected scenarios, the impacts on the building were assessed and compared, quantifying heat release rates, radiative heat flux and adiabatic surface temperature. Implications. This research contributes to a Performance-Based Design (PBD) approach for buildings in the WUI.