Author(s): D. A. Botelho; I. L. Teakle; M. Barnes; M. E. Barry; R. Baheerathan; G. Shiell; G. C. Collecut
Linked Author(s):
Keywords: Outfalls; Linkage techniques; CFD; Tuflow fv; Nearfield model; Farfield model
Abstract: One of the biggest challenges in ocean outfall modelling is the need to examine mixing and dispersion processes at contrasting spatial and temporal scales. These scales range from millimetres and seconds near a diffuser to kilometres and hours further afield, and describe both hydrostatic and non -hydrostatic processes. Common practice to date has been the use of separate nearfield and farfield models to support mixing assessments at small and large scales, respectively. One of the main shortcomings of this approach is the resultant poor representation of plume dilutions at intermediate spatial and temporal scales where both models have limitations, for example, around the simulation of unsteady flows. This can lead to inconsistency in process prediction. As a means of overcoming this inconsistency, techniques to dynamically link these models have been developed and tested on a real case study. This paper presents recent advancements in such techniques so as to incorporate spatially-and-temporally variant nearfeld model dilutions into farfield models at the same time mass (and heat) conservation are readily enforced. A study case is presented in which a Computational Fluid Dynamics (CFD) model was used to make predictions in the nearfield and the linkage technique is applied to provide realistic simulations of effluent concentrations in the farfield.
Year: 2016