Prediction of the air pollution in workplaces near railways

Abstract

Abstract.  Purpose. Development of a CFD model for estimating the level of air pollution in the working areas near the railroad during coal transportation. Methodology. To solve the problem, a CFD model based on the application of the equations of motion of inviscid incompressible fluid and mass transfer has been developed to determine the velocity field of the wind flow near the wagon and in the working area near the railway line. For numerical integration of the coal dust transfer equation, an implicit alternating-triangular difference scheme was used. When constructing a difference scheme, the transport equation is split, which makes it possible to construct an effective algorithm for solving a differential problem. The unknown value of the concentration of coal dust at each step of the splitting is determined by the explicit scheme – the running counting method, which ensures a simple numerical realization of the splitting equations. For the numerical integration of the equation for the velocity potential, the Richardson method is applied. The developed numerical models form the basis of the created package of applied programs. Based on the constructed numerical models, a 3D computational experiment was performed to estimate the level of atmospheric pollution during the removal of coal dust from a wagon. Findings. A 3D numerical model has been developed that belongs to the class of "diagnostic models". This model takes into account the main physical factors that affect the process of dispersal of coal dust in the work area near the railway line during the transportation of coal. The proposed model requires a small amount of computer time in practical implementation on small and medium power computers. This model can be used to perform calculations to assess the influence of various factors on the level of contamination of working areas near the railroad. Calculations have been performed to determine the concentration of coal dust in the working area near the railway car. The results of a laboratory experiment on the study of the formation of contamination zones near the car model are presented. Originality. A CFD model has been created that allows to take into account the significant factors that influence the process of coal dust dispersion in working areas near the railway main  Practical value. An effective CFD model for the express calculation of the level of air pollution in working areas near the railway line for the transportation of coal is considered. The model can be applied to the development of measures to protect workers of the mainland from dust pollution. The proposed model allows to calculate the 3D aerodynamics of the air flow and the process of scattering of coal dust on the mainland territory.