NUMERICAL SIMULATION OF ATMOSPHERIC POLLUTION DURING AN EXTREME SITUATION AT A CHLORINE OVERFLOW STATION

Abstract

Problem statement. The problem of forecasting the dynamics of the formation of zones of chemical pollution due to accidental emissions of chlorine at the chlorine overflow station is considered. There is a large village near this chlorine overflow station, so in case of an emergency there is a risk of toxic damage to people. From this point of view, the development of effective multidimensional mathematical models to predict the formation of zones of chemical contamination is of great relevance. The purpose of the article. Development of a numerical multi-parameter model and computer program for forecasting the dynamics of air pollution due to accidental leakage of chlorine at the chlorine station. Methodology. For mathematical modeling of the propagation of a chemically hazardous substance, a three-dimensional equation of mass transfer is used (the equation of G.I. Marchuk). This modeling equation takes into account different wind directions, changes in the vertical coefficient of atmospheric diffusion with height, the intensity of the release of a chemically hazardous substance, and the location of the emission source. For the numerical integration of the three-dimensional mass transfer equation, finite-difference splitting schemes are used. First, for the modeling equation of mass transfer, its physical splitting is carried out: the equations of transfer due to velocity and due to diffusion are considered separately. Also, a separate step is to change the concentration of a chemically hazardous substance due to the action of a pollution source. Next, a difference splitting scheme is constructed. At each step of the splitting, the value of the concentration of a chemically hazardous substance is determined according to an explicit scheme. Scientific novelty. A numerical model is proposed to calculate the dynamics of accidental air pollution due to the release of chemically hazardous substances. The mathematical model takes into account the physical factors that significantly affect the process of distribution of chemically hazardous substances in the atmosphere. Practical significance. Based on the developed model, a code is created that allows you to quickly calculate the process of accidental air pollution. The mathematical model can be used in developing an emergency response plan. Conclusions. The developed mathematical model and the computer code that implements it allow us to study the dynamics of the spread of chemically hazardous substances in the air. The developed computer program can be implemented on low and medium power computers. The results of a computational experiment are presented.