Abstract. In this paper, a three-dimensional two-phase flow solver, SedFoam-2.0, is presented for sediment transport applications. The solver extended from twoPhaseEulerFoam available in the 2.1.0 release of open-source CFD (computational fluid dynamics) toolbox OpenFOAM. approach phase modeled as continuum, and constitutive laws have to be prescribed stresses. proposed two different intergranular stress models are implemented: kinetic theory granular flows dense rheology μ(I). For stress,...

In this work, the modelling of collisional bedload transport is investigated with a focus on continuum granular flow. For purpose, frictional–collisional approach, combining Coulomb model kinetic theory flows, developed. The methodology based comparison coupled fluid–discrete simulations that classical fails to reproduce. This inaccuracy may be explained by assumptions negligible interparticle friction and absence saltation in approach. order provide guidelines for modelling, fluctuating...

Abstract. In this paper, an Eulerian two-phase flow model, sedFoam, is extended to include air phase together with its water and sediment phases. The numerical model called sedInterFoam implemented using the open-source library OpenFOAM. includes previous features of sedFoam for transport modeling also solves air–water interface volume-of-fluid method coupled waves2Foam toolbox free-surface wave generation absorption. Using sedInterFoam, four test cases are successfully reproduced validate...

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...

The flow of a hyperpycnal river plume into lake with an inclined bed and without any lateral confinement is common occurrence in nature.  A characteristic example such geophysical fluid system the one  sediment-laden dense inflows freshwater lakes (e.g. Rhone - Geneva). In this case, plunging process close to mouth, as well its dependence on properties inflow, affect critically subsequent hydrodynamics lake. better understanding these processes therefore significant for...

We have investigated the modeling of collisional bed-load transport with a focus on continuum approaches for granular flow. A frictional-collisional framework, combining Coulomb model and kinetic theory flows, is proposed to address limitations classical theory, which fails accurately reproduce results from coupled fluid–discrete simulations. These discrepancies are attributed assumptions negligible interparticle friction absence saltation in formulations. To guide...

This paper presents a numerical investigation of the scour phenomenon around submarine pipeline. The simulations are performed using SedFoam, two-phase flow model for sediment transport implemented in open source Computational Fluid Dynamics (CFD) toolbox OpenFOAM. focuses on sensitivity granular stress and turbulence with respect to predictive capability model. quality simulation results is estimated statistical estimator: Brier Skill Score. show no However, strongly depend choice model,...

In submerged sandy slopes, soil is frequently eroded as a combination of two main mechanisms: breaching, which refers to the retrogressive failure steep slope forming turbidity current, and instantaneous sliding wedges, known shear failure, that also contribute shape morphology deposit. Although there are several modes failures, in this paper we investigate breaching failures granular columns using two-fluid approach. The numerical model first applied simulate small-scale column collapses...

Abstract State-of-the-art technologies for wind and tidal energy exploitation focus mostly on axial turbines. However, cross-flow hydrokinetic turbines possess interesting features, such as higher area-based power density in array installations shallow water, well a generally simpler design. Up to now, the highly unsteady flow conditions cyclic blade stall have hindered deployment at large scales because of resulting low single-turbine efficiency fatigue failure challenges. Concepts exist...

When a deposited layer of granular material fully immersed in liquid is suddenly inclined above certain critical angle, it starts to flow down the slope. The initial dynamics these underwater avalanches strongly depends on volume fraction. If bed initially loose, i.e. looser than state, avalanche triggered almost instantaneously and exhibits strong acceleration, whereas for an dense bed, denser avalanche's mobility remains low some time before flowing normally. This behaviour can be...

In this paper, two-phase flow simulations of oscillatory sheet experimental configurations involving medium and fine sand using a turbulence-resolving two-fluid model are presented. The reproduces the differences behaviour observed between whereas turbulence-averaged models require an almost systematic tuning empirical coefficients for turbulence–particle interactions. explicitly resolves these interactions can be used to study in detail experimentally. Detailed analysis concentration...

Abstract Placing two counter-rotating rotors of a Vertical Axis Wind Turbine (VAWT) can lead to significant power enhancement and faster wake resorption. This global output is directly related the spacing between both permitting mutual confinement effect. In addition, relative direction angular velocity strongly impact overall performances machine. A range two-dimensional (2D) Unsteady Reynolds Averaged Navier-Stokes (URANS) simulations has been managed in order study aerodynamic...

Abstract. In this paper, a three-dimensional two-phase flow solver, SedFoam-2.0, is presented for sediment transport applications. The solver extended upon twoPhaseEulerFoam available in the 2.1.0 release of open-source CFD toolbox OpenFOAM. approach phase modeled as continuum, and constitutive laws have to be prescribed stresses. proposed two different inter-granular stress models are implemented: kinetic theory granular flows dense rheology μ(I). For fluid stress, laminar or turbulent...

Abstract

FluidDyn is a project to foster open-science and open-source in the fluid dynamics community. It thought of as research channel dynamics, methods tools do science. We propose set Python packages forming framework study with different methods, particular laboratory experiments (package fluidlab), simulations (packages fluidfft, fluidsim fluidfoam) data processing fluidimage). In present article, we give an overview specialized then focus on base package called fluiddyn, which contains common...

Population extinction due to the accumulation of deleterious mutations has only been considered occur at small population sizes, large sexual populations being expected efficiently purge these mutations. However, little is known about how mutation load generated by segregating affects size and, eventually, extinction. We propose a simple analytical model that takes into account both demographic and genetic evolution populations, linking size, density dependence, load, self-fertilisation....

Abstract The characteristics of the fluid–structure interaction on flexible blades a horizontal-axis water turbine are studied; this bioinspired technology features mechanical simplicity, performance and lifetime improvement, low fish impact risk, all truly sustainable renewable energy exploitation. A surface-tracking method synchronized with force measurements was applied surrogate model single-bladed, vertical-axis in channel. This allows for characterization structural deformations their...