3rd International E-Conference on Engineering, Technology and Management - ICETM 2020
Author(s) : Domingos Xavier Viegas, EusÃ©bio ConceiÃ§Ã£o, JoÃ£o Gomes, Jorge Raposo, Maria Manuela LÃºcio, Maria Teresa Viegas
In this work a numerical model of the pine tree thermal behaviour, nearby a forest fire environment, is developed and applied. The pine tree thermal behaviour numerical model is based on energy balance integral equations for the tree elements and mass balance integral equations for the water in the tree elements. The numerical model considers the heat conduction through the tree elements, heat exchanges by convection between the external tree surfaces and the environment, heat exchanges by radiation between the flame and the external tree surfaces and water heat loss by evaporation from the tree to the environment. The numerical simulation applied in this study considers the mean fire front temperature of 500ÂºC, the air temperature of 40ÂºC, the air velocity of 10 m/s and the air relative humidity around the pine tree of 50%. The Mean Radiant Temperature (MRT) and the external surface temperatures, that each element (trunks, branches and leaves) of the pine tree is subjected, were calculated. The values of the MRT and surface temperatures of the pine tree are highest in the side of the fire front and decrease from the first level, located near the ground, to the last level, corresponding to the top of the pine tree.