Comparison of a Diffusion Model with Dye Dispersion Measurements to Study Turbulence in Coastal Waters

摘要

The operation of a coastal power plant provides the opportunity to conduct studies, which deals with circulation and horizontal mixing in coastal waters near a power plant. This study was initiated with field experiments in which small quantities of rhodamine dye solution were dispersed in the inlet and outlet bays adjacent to the power station. Sequential aerial photographs permitted the estimation of the magnitude of horizontal mixing (diffusion) coefficients. The high cost of the dye, however, makes the utilization of diffusion models an attractive supplement to such studies, since the model can be run a number of times with varied parameters. The simulated concentration fields can then be compared with the field experiments. The simple diffusion model selected for this study is based on a point discharge of a dye solution. The model assumes an isotropic field with a diffusion coefficient constant over the period of the study. To simulate the two-dimensional dye patches, an equispaced grid (441 points) was used with 5m between grid points. The time step was set for 10 minute intervals. The results of the comparison between the numerical simulation and a dye experiment are discussed.