Design of Three-Dimensional Pine Tree Geometry and the Radiation Heat Exchanges in Fire Environments
Authors: Eusébio Conceição, João Gomes, Maria Manuela Lúcio, Rafael Raposo, Xavier Viegas, Maria Teresa Viegas
Abstract: This work presents a design of a three-dimensional pine tree geometry and the ra-diation heat exchanges in forest fire environments. Using Computer Aided De-sign software, the pine tree geometry design is developed in this study. The radia-tion heat exchanges are evaluated between the pine tree and the forest fire plan surface. The geometry, applying mesh generation, is used to evaluate the view factors, which in turn are used to calculate the heat exchanges by radiation. The virtual pine tree geometry has a height of 7.5 m and is constituted by 8863 cylin-drical elements. The pine tree is constituted by trunks, branches and leaves. The fire front has 10 m long and 1 m high, which is located at a distance of 5 m from the virtual pine tree. The numerical results of the geometry, mesh generation, the view factors and Mean Radiant Temperature (MRT) are obtained. In this study, a statistical function was used to randomly place the leaves determined to be includ-ed in the numerical model of the pine tree. The results show that the use of a per-centage of 20% of the total number of leaves makes it possible to guarantee that the distribution of MRT in the various elements of the pine tree remains practical-ly equal to the use of the total number of leaves.
Keywords: Design, Forest Fire, Numerical Models, Tree Thermal Response
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