Refined Numerical Simulation of Environmental Flow, Mixing and Transport in Amazon River Near Manaus City Closed by Multiple Turbulence Models

摘要

This paper reports a refined numerical simulation for Amazon River, aiming to develop a mathematical model and numerical tool for modeling and predicting turbulence flows and contaminant transport in complex natural waters. In the mathematical model, the depth-averaged two-equation closure turbulence k-ω model, together with k-ε model and k-w model, were used to close non-simplified quasi 3D hydrodynamic fundamental governing equations. The discretized equations, however, were solved by advanced multi-grid iterative method under coarse and fine two-levels' non-orthogonal body-fitted grids with collocated variable arrangement. Except for steady flow and transport computation, the processes of black-water inpouring and plume development, caused by the side-discharge from the Negro River, also have been numerically studied. The used three depth-averaged two-equation closure models are suitable for modeling strong mixing turbulence. The recently built k-ω turbulence model with higher order of magnitude of transported variable ω provides a possibility to enhance the computational precision. Based on the developed mathematical model, which can provide multiple turbulence two-equation closure models for quasi 3D modeling, a CFD software, namely Q3drm1.0 and Q3drm2.0, was developed. This numerical tool focuses on the refined numerical simulations of the steady and unsteady problems of flow and transports with the strong ability to deal with different tipes of discharges. In this paper, only the investigation of side-discharge is presented.