REASONABLE DERIVATION OF HYDRAULIC CONDITION FOR CFD IN Zhenjiang CITY

Abstract

It is with much frequency that we can't get enough field data to define boundary conditions for hydraulic calculations especially in developing countries. The authors faced this kind of problem in a research on water exchange of the Neijiang, a tideland located in the lower reach of the Changjiang in China. This paper presents a process to estimate the boundary conditions for quasi-3D numerical simulation from limited available data: The water exchange of the Neijiang is controlled by the flow rate and the water stage of Changjiang which are highly changed in a day by tidal waves going up from the river mouth. In this study, 1-D unsteady flow model was constructed and calibrated by using the monthly flow rate at a far upstream station free from the tidal effect and the hourly data of tidal level at the river mouth, and the flow rate and the water level near the tideland necessary for the quasi-3D calculation were estimated. The results were checked by the water level data at one of the mouths of the Neijiang.