Understanding small-scale turbulent mixing in the ocean is fundamental for accurately modeling oceanic processes, predicting currents, and managing marine ecosystems. Global regional models rely on parameterizing mixing, yet this remains a significant source of uncertainty due to technical constraints model-specific empirical assumptions. Furthermore, when coupled with biogeochemical models, uniform parameterization typically applied all tracers, overlooking distinct properties each. This...

In this contribution, we present 3D two-phase flow simulations of lock-release turbidity currents using sedFOAM. The Large Eddy Simulation is used for the turbulence modeling while granular stresses are modeled a frictional-collisional kinetic theory including interparticle friction (Chassagne et al., 2023). Simulations performed different bed slopes, initial volume fractions and particle diameter density. numerical results compared with experiments in terms front propagation current shape...

Abstract The interaction of quasi‐steady abyssal ocean flow with submarine topography is expected to generate turbulent mixing in the ocean. This may occur locally, close topography, or via breaking lee waves that can carry energy into interior. There currently no theoretical, empirically derived, prediction for relative amounts local and interior mixing. We report measurements rate laboratory experiments a topographic ridge towed through density stratification. span three parameter regimes...

Geophysical flows support the propagation of stable nonlinear internal waves (internal solitary or ISWs) with complex generation mechanisms. At least two regimes ISWs in pycnocline, both involving interaction between a tidal flow and bottom topography, are known ocean. They can either be directly induced above topographies (primary generation) by topographic wave beam impinging on pycnocline. This “secondary generation” process is subject-matter present study. The work relies direct...

We modeled internal tide generation above a high sinusoidal ridge in fluid with mid-depth pycnocline and developed an original method to quantify vertical mode amplitude two-dimensional-vertical simulations. Since lowest modes can propagate over considerable distances, while are more likely dissipate locally, estimating the tidal energy distribution among is necessary investigate spatial redistribution of energy. Our numerical approach allows expansion verification previous analytical...

This work presents a simple analytical model for the streamwise and radial variations of turbulent kinetic energy dissipation in an incompressible round jet. The key assumptions are: similarity axial velocity profile with Gaussian shape, axisymmetric flow dominance derivatives mean over direction (similar to boundary layer theory). Initially, simplified eddy-viscosity relation stresses is derived using algebraic stress by Gatski & Speziale ( J. Fluid Mech. , vol. 254, 1993, pp. 59–78)....

Internal solitary waves (ISWs) are large amplitude stable propagating in regions of high density gradients such as the ocean pycnocline. Their dynamics has often been investigated two-dimensional approaches, however, their three-dimensional evolution is still poorly known. Experiments have conducted stratified water tank CNRM-GAME to study generation ISWs two academic configurations inspired by oceanic regimes. First, ultrasonic probes used measure interfacial displacement configurations. In...

In the present work, we study flow of thixotropic yield stress fluids between two concentric cylinders. order to take into account thixotropy, constitutive relation uses a structural parameter which is driven by kinetic equation. Here, Houska's model considered. Depending on breakdown rate parameter, localization or shear-banding are observed. We show that for fragile structures, may be observed although stronger only localisation such as in Bingham fluids. Physical explanations discussed...

Numerical experiments have been carried out using a nonhydrostatic and non-Boussinesq regional oceanic circulation model to investigate the nonlinear processes generated by supercritical tidal flow in shallow straits. Our approach relies on idealized direct numerical simulations inspired observations. By analyzing large set of simulations, regime diagram is proposed for lee these The results show that topography shape strait plays crucial role formation internal solitary waves (ISWs)...

Abstract The energy pathways from propagating internal waves to the scales of irreversible mixing in ocean are not fully described. In interior, triadic resonant instability is an intrinsic destabilization process that may enhance cascade away topographies. present study focuses on integrated impact processes induced by a propagative normal mode‐1 over long‐term experiments idealized setup. wave dynamics and evolution density profile followed using light attenuation technique. Diagnostics...

Abstract The generation of topographic internal waves (IWs) by the sum an oscillatory and a steady flow is investigated experimentally with linear model. two forcing flows represent combination tidal constituent weaker quasi‐steady interacting abyssal hill. combined forcings cause coupling between tides lee that impacts their dynamics IWs as well energy carried away. An asymmetry observed in structure upstream downstream IW beams due to quasi‐Doppler shift effect. This enhanced for narrowest...

The present work investigates the dynamical characteristics of a gravity current produced by continuous and steady release dense fluid, with source density ρ0, into lighter ambient ρa < ρ0. A planar geometry is considered in which fluid initially at rest inside rectangular tank continuously released from located bottom-left corner tank.  propagates along horizontal bottom boundary domain displacing fluid. This configuration has been...

Particle-laden gravity currents (PLGCs) are driven by the mass difference between a heavy fluid-particle mixture and lighter ambient liquid. They often occur in natural industrial situations, among which typical situation is release of finite volume. Here, we focus on such `dam-break' studied using lock-release devices at laboratory scale. The objective presententation to provide description macroscopic scale early moments flow, namely slumping regime, with respect relevant dimensionless...

Earth and Space Science Open Archive This work has been accepted for publication in Journal of Geophysical Research - Oceans. Version RecordESSOAr is a venue early communication or feedback before peer review. Data may be preliminary. Learn more about preprints. preprintOpen AccessYou are viewing the latest version by default [v1]Asymmetric internal tide generation presence steady flowAuthors Yvan Dossmann iD Callum J. Shakespeare Kial Douglas Stewart Andrew McC. Hogg iDSee all authors...