Author(s): Shuen Law; Mark Davidson; Craig Mcconnochie; Daniel Lagrava

Linked Author(s): Mark Davidson

Keywords: Marine discharge; Negatively buoyant jets; Buoyancy-induced instabilities; Large eddy simulations; Adaptive mesh

Abstract: Flows generated from the marine outfalls of large-scale desalination plants are often in the form of inclined negatively buoyant jets (INBJs) prior to reaching the sea-bed. Integral models are commonly used to predict the behavior of these discharges for environmental impact assessments and are considerably less resourceintensive when compared to CFD (computational fluid dynamics) simulations. However, significant discrepancies between the integral model outputs and experimental data remain. Computational fluid dynamics simulations potentially offer the opportunity to analyse these flows in more detail because they provide the freedom to extract 3-D information in various forms, which can drive further improvements to the relatively simple integral models. In this study, the outputs from a high-resolution large eddy simulations (LES) of INBJ are analysed. The LES made use of a Lagrangian dynamic sub-grid scale model and an adaptive meshing system with a novel refinement criterion. The simulation results have been validated against published 2-D experimental data and is shown to provide improved predictions relative to existing numerical models. This paper discusses the potential of this Adaptive LES approach in offering additional insights into the buoyancy-induced detrainment highlighted in previous studies of INBJs.

DOI: https://doi.org/10.3850/978-90-833476-1-5_iahr40wc-p0651-cd

Year: 2023