Advanced modeling of particle-laden gravity currents over flat and wavy surfaces using a residual-based variational multi-scale approach

Resumo

In this study, we introduce a numerical framework for simulating dilute particle-laden gravity currents at high Reynolds numbers (Re) using a residual-based variational multi-scale (RBVMS) approach. Our formulation effectively represents the coupling between velocity fine scales and the residual of the density concentration equation, ensuring a more accurate and robust representation of the underlying physical processes.We simulate lock-exchange particle-laden gravity currents across different Reynolds numbers to evaluate the proposed methodology. First, we validate the formulation by modelling gravity currents over flat terrain. Subsequently, we extend our analysis to particle-laden gravity currents over wavy terrains and varying wave heights to explore their influence on flow. Results indicate that floor roughness reduces the front velocity while significantly enhancing instabilities, leading to the earlier emergence of secondary instabilities. Additionally, roughness serves as an additional vorticity generation mechanism. Findings demonstrate that the (RBVMS) framework achieves high accuracy while requiring significantly low mesh resolution.