Numerical simulations of flow and contaminant transport using multiple depthaveraged two-equation turbulence models in the Solimões river near the Anamã city

This paper reports a quasi 3D numerical simulation in a curved river reach of the Solimões River near The Anamã City, Brazil, aiming to develop a numerical tool for modeling turbulentflows and pollutant transport in complex natural waters. The recently built depth-averaged two-equation turbulence  ~~ k  model, together with  ~ ~ k  and k w~ ~  models were used to close non-simplified quasi 3D hydrodynamic fundamental governing equations. The discretized equations were solved byadvanced multi-grid iterative method under non-orthogonal bodyfitted coarse and fine two-levels’ grids with collocated variable arrangement. Except for steady flow and transport computation, the processes of contaminant inpouring and plume development,caused by the side-discharge from a tribytary, also have been investigated numerically. The used three closure approaches are suitable for modeling strong mixing turbulence. The established  ~ ~ k  model with higher order of magnitude of transported variable  ~ provides a possibility to elevate the computational precision. Based on the developed hydrodynamic model, a CFD (Computational Fluid Dynamics) software, namely Q3drm1.0, wasdeveloped. This tool focuses on the refined simulations of the steady and unsteady problems of flow and temperature/contaminant transports in complicated computational domains with the strong ability to deal with different types of discharges: side-discharge, point-source discharge/point-sink, and area-source discharge from the slope along bank. In this paper, only the study of side-discharge is presented.

Keywords:

Depth-averaged turbulence models , Contaminant transport , Numerical modeling , River modeling , Multi-grid iterative method , Side-discharge