A depth integrated numerical model has been refined to simulate the tidal flows in a model square harbour. The harbour entrance width is narrow and of similar dimensions to the mean water depth. The advective accelerations and the turbulence stress terms of the governing hydrodynamic equations are therefore significant in describing the complex flow patterns. A split-operator approach is employed in the model with the advective terms solved by the minimax-characteristics method. The turbulence stress terms have been examined in detail and three important components established, including: bottom generated turbulence, jet induced turbulence and momentum dispersion due to the vertical integration of the secondary motion arising from the horizontal curved flow. An order of magnitude estimation has shown that the momentum dispersion is of primary importance. A simple zero order turbulence model has been used to account for the three mechanisms, with a semi-slip boundary condition being included to cater for the wall shear. Convergence of the solution has been achieved by successively reducing the time step and grid size. The computed results have been shown to compare well with experimental measurements.
ASJC Scopus subject areas
- Civil and Structural Engineering
- Water Science and Technology