Abstract
The three-dimensional (3-D) modelling of water systems involving double-diffusive processes is challenging due to the large computation times required to solve the flow and transport of constituents. In 3-D systems that approach axisymmetry around a central location, computation times can be reduced by applying a 2-D axisymmetric model set-up. This article applies the Reynolds-averaged Navier–Stokes equations described in cylindrical coordinates and integrates them to guarantee mass and momentum conservation. The discretized equations are presented in a way that a Cartesian finite-volume model can be easily extended to the developed framework, which is demonstrated by the implementation into a non-hydrostatic free-surface flow model. This model employs temperature- and salinity-dependent densities, molecular diffusivities, and kinematic viscosity. One quantitative case study, based on an analytical solution derived for the radial expansion of a dense water layer, and two qualitative case studies demonstrate a good behaviour of the model for seepage inflows with contrasting salinities and temperatures. Four case studies with respect to double-diffusive processes in a stratified water body demonstrate that turbulent flows are not yet correctly modelled near the interfaces and that an advanced turbulence model is required.
Original language | English |
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Pages (from-to) | 521-540 |
Journal | Geoscientific Model Development |
Volume | 11 |
DOIs | |
Publication status | Published - 6 Feb 2018 |
Keywords
- axisymmetric model
- CFD modelling
- density-driven flow
- double diffusion
- double-diffusive convection
- heat transport
- non-hydrostatic model
- numerical modelling
- salt transport
- salt-fingers
- SWASH (Simulating WAves till SHore)
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An axisymmetric hydrodynamical model: model code and data
Hilgersom, K. P. (Creator), Zijlema, M. (Creator) & van de Giesen, N. C. (Creator), TU Delft - 4TU.ResearchData, 3 Apr 2017
DOI: 10.4121/UUID:95227D5D-2CF0-44EC-AB2D-705A626DCDF4
Dataset/Software: Dataset