Nguyen X. Numerical simulation for unsteady pollution processes in rivers

Object - flows and pollution spreading in rivers. The purpose - to obtain mathematical models, methods and algorithms for investigation of unsteady hydrodynamical and hydromigration processes of pollution spreading in rivers. The mathematical model is basing on the 2-D depth averaged system equations of river hydraulics and the planed equation of convective-diffusive pollution transfer. The numerical methodology is based on the idea of splitting the convective matrixes into the sign-defined ones, suitable for applying the stable up-wind differential scheme. Computational algorithm is characterized by using marker's system to identify geometric form of the computational domain. The obtained program is able to afford at new level to predict water quality in real rivers taking into account almost important factors that affect the hydrodynamic regime as well as the process of migration of polluted substances in river such as: the presence of isles, hydro-technical structures, inflows, water taking away, irregularity of water depth, etc. Numerous results of computational experiments have been presented concerning prediction of pollution spreading in parts of the Dniepr-Samara Rivers as well as the Kilchen River of the Dniepropetrovsk city. The scientific results have found aplication in practices.