Assessment of the level of atmospheric pollution by railway in coal transportation

Abstract

Abstract. Purpose. The development of numerical models for the prediction of atmospheric pollution during transport of coal in the railway carriage. Methodology. To solve this problem developed numerical models based on the use of the equations of motion of an inviscid incompressible fluid and mass transfer, to determine the field of wind velocity near the wagons and dispersion of dust in the atmosphere. For the numerical integration of the transport equation of the pollutant used implicit alternating-triangular difference schemes. When constructing a difference scheme is carried out splitting the transport equation that allows us to construct an efficient algorithm for solving a differential problem. Unknown value at every step of splitting the pollutant concentration determined by the explicit scheme – the method of running account, which provides a simple numerical implementation splitting equations. For numerical simulations of implicit difference scheme is used for the velocity potential. The developed numerical models are the basis of established software package. On the basis of the constructed numerical models carried out a computational experiment to assess the level of air pollution when transporting bulk cargo by rail. Findings. Developed numerical models that belong to the class «diagnostic models». These models take into account the main physical factors affecting the process of dispersion of dust pollution in the atmosphere during transportation of bulk cargo, but require a small cost of the computer time in the practice of in the low and medium power machines. These models are used for serial calculations of various situations of scenarios related to issues of environmental protection and pollution intensity diagnostics for different weather conditions. Submitted computational calculations to determine pollutant concentrations and the formation of the zone of pollution near the train with bulk cargo in «microscale» scale. Originality. Created numerical models to take into account the relevant factors influencing the process of dispersion of pollutants in the atmosphere, and the formation of the zone of pollution during transport of bulk cargo by rail. Practical value. Considered efficient numerical models «diagnostic models» for rapid calculation of the level of pollution of the atmosphere during transportation of bulk cargo by rail. The models can be used in the development of environmental protection measures in the operation of rail transport. The proposed model allows to calculate the 2D hydrodynamics wind flow and the process of mass transfer of pollutants in the atmosphere.