Patterns of Pollutants Distribution from Vehicles to the Roadside Ecosystems

This paper focuses on the determination of the motor vehicles pollutants emission and distribution in space and time within roadside ecosystems. The need for improvement of the mathematical model of emission distribution and the spreading of pollutants from highways is related to the non-stationary transport flow. The results of research show the spread of pollutants in the roadside ecosystem is carried out by the transfer of air flows (advective and convective components) and diffusion (fluctuation movements relative to the transfer process). Obtained analytical dependences for the forecast estimations of pollutants concentrations in the air allow to design a spatial concentration field at any atmospheric states and air flow velocity. The adequacy of the developed mathematical model was checked using instrumental methods. As exemplified by sulfur dioxide, it has been determined that its concentration in the air varies exponentially depending on the distance from the road and at a distance of 30 m is reduced three-fold, reaching the level of 0.8 mg/m³. The Ansys 17.0 software visualized the distribution of waste gases from a truck and determined that the bulk of pollutants deposited at a distance of 30 m from the road. The fields of concentration of the respective harmful substances in the roadside zone were obtained and the places of secondary entry of settled harmful impurities from the roadway were determined again in the atmospheric air.