Mathematical simulation of inert heating and pyrolysis of forest fuel under the influence of a forest fire front, if the process of sooting is taken into account

Introduction. Large amounts of pollutants, including carbonaceous particles of soot, are released into the atmosphere during a forest fire. High concentrations of these particles in the air can lead to the development of cardiorespiratory diseases or death. It has been noticed that a certain number of soot particles is produced at the stage of forest fuel pyrolysis. In this regard, it is advisable to study the processes of pyrolysis and sooting to develop effective methods of their prediction and prevention. Goal of the study. The goal of this study is the mathematical simulation of heat transfer in an element of standard forest fuel (a birch leaf), taking into account the thermal decomposition of dry organic matter and sooting. Materials and methods. Within the framework of the work, scenario modeling of heat and mass transfer processes in an element of forest fuel (a birch leaf), subjected to the influence of a high-temperature environment, was conducted. A one-dimensional heat transfer equation and a kinetic equation, having respective initial and boundary conditions, were solved by means of numerical simulation. The finite difference method was employed to solve the resulting system of differential equations. The calculations were conducted using the RAD Studio software package. Graphical results were processed using the OriginPro software package. Results. Scenario modeling took into account the type of forest fire, the period of the fire hazard season, forest fuel properties, the degree of the forest fuel dispersion, and the initial moisture content in a forest fuel element. The authors have found that the major influence is made by the extent of dispersion and the type of forest fire. The similarity of qualitative characteristics of sooting has also been established for all types of forest fires. Conclusion. The proposed mathematical model can be used in conjunction with geoinformation systems to visualize the initial and output information in the process of assessment, monitoring and forecasting of forest fires and their environmental consequences.