Analysis of one-dimensional models for exchange flows under strong stratification

Autor: Vincenzo Armenio, Herman Clercx, Koen J. van de Wal, Steven J. Kaptein, Matias Duran-Matute, Leon P. J. Kamp
Přispěvatelé: Fluids and Flows, Applied Physics and Science Education, EIRES Eng. for Sustainable Energy Systems, Transport in Environmental Flows (Duran Matute), Transport in Turbulent Flows (Clercx), Kaptein, S. J., van de Wal, K. J., Kamp, L. P. J., Armenio, V., Clercx, H. J. H., Duran-Matute, M.
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Ocean Dynamics, 70(1), 41-56. Springer
ISSN: 1616-7228
1616-7341
Popis: One-dimensional models of exchange flows driven by horizontal density gradients are well known for performing poorly in situations with weak turbulent mixing. The main issue with these models is that the horizontal density gradient is usually imposed as a constant, leading to non-physically high stratification known as runaway stratification. Here, we propose two new parametrizations of the horizontal density gradient leading to one-dimensional models able to tackle strongly stratified exchange flows at high and low Schmidt number values. The models are extensively tested against results from laminar two-dimensional simulations and are shown to outperform the models using the classical constant parametrization for the horizontal density gradients. Four different flow regimes are found by exploring the parameter space defined by the gravitational Reynolds number Reg, the Schmidt number Sc, and the aspect ratio of the channel Γ. For small values of RegΓ, when diffusion dominates, all models perform well. However, as RegΓ increases, two clearly distinct regimes emerge depending on the Sc value, with an equally clear distinction of the performance of the one-dimensional models.
Databáze: OpenAIRE
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