A One-Cell Local Multigrid Method for Solving Unsteady Incompressible Multiphase Flows

Vincent, Stéphane; Caltagirone, Jean‐Paul

doi:10.1006/jcph.2000.6566

Cited by 66 publications

(45 citation statements)

References 39 publications

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“…The temporal discretization and the coupling between velocity and pressure are achieved using an augmented Lagrangian method. 10,11) The advection terms in (1), (3) are evaluated by a hybrid scheme 12) whereas a centered scheme is used for the other terms. The linear system is solved by an iterative Bi-Conjugate Gradient Stabilized technique.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Numerical Simulation of Gas-Jet Wiping in Steel Strip Galvanizing Process

Lacanette¹,

Vincent²,

Arquis³

et al. 2005

ISIJ Int.

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We have investigated the film thickness and thermal exchange occurring during the coating and cooling of a liquid film on a substrate. The aim of our study is to demonstrate the interest of Direct Numerical Simulation tools for Interfacial flows to understand, on the one hand, the mechanisms involved in the deposition of the film on the moving substrate, and on the other, to measure characteristic parameters of the process. The direct numerical simulation is presented here in two-dimensions based on the Navier-Stokes equations, generalized to free surface flows. They are approximated by VOF (Volume Of Fluid) methods. A Large Eddy Simulation (LES) model is used to take the turbulence into account. We attempt to define the governing parameters of the process and propose a description of the flow. The characteristic parameters of the wiping of the film and the associated thermal exchanges are presented in terms of wiping thickness, transfer coefficient, cooling rate and temperature gradient along the film.

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Section: Methodsmentioning

confidence: 99%

“…[11][12][13] Concerning the turbulence, the LES is based on a concept of scale separation in which the larger structures are solved (1)-(4) directly and the smaller ones are modeled (5), (6). From a numerical point of view, the scale separation is carried out on the local space scale through spatial filtering.…”

Section: Methodsmentioning

confidence: 99%

Numerical Simulation of Gas-Jet Wiping in Steel Strip Galvanizing Process

Lacanette¹,

Vincent²,

Arquis³

et al. 2005

ISIJ Int.

Self Cite

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“…The scheme reduces possible numerical oscillations and reduces the diffusion of the first order scheme. A three dimensional version of this VOF-TVD scheme was implemented in Thétis (Vincent, 1999;Vincent and Caltagirone, 2000). This method is fast and reproduces accurately the interface but diffusion of the interface might appear when breaking and rupture happen at the free surface (Lubin et al, 2006).…”

Section: Tvd Schemementioning

confidence: 99%

Effects of tidal bores on turbulent mixing: a numerical and physical study in positive surges

Simon

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Tidal bores are positive surges created by the flooding of tides inside estuaries and rivers. They propagate upstream in an estuary sometimes as several metre high waves. Tidal bores are fascinating phenomenon with some impact on the wildlife, the mixing and re-suspension of sediments, and river constructions. Field studies remain challenging due to the violent nature of some bores. Herein, the hydrodynamics of tidal bores was investigated in a complementary study with experimental measurements and numerical simulations of idealised models of tidal bores. While laboratory experiments offer an accurate way to measure the flow properties, numerical simulations provide rather detailed information on the hydrodynamics of bores. These simulations require detailed experimental data to accurately replicate the experiments and validate the numerical methods.Investigations were conducted at the University of Queensland in a large rectangular channel partially covered by a fixed gravel bed. The steady flow condition properties were investigated using a Pitot tube and acoustic Doppler velocimeters (ADVs). The unsteady flow conditions were obtained by the fast closure of a downstream gate, which led to an upstream propagating bore. Free surface characteristics were studied for several types of bores, from undular to breaking. Those measurements showed large free surface fluctuations during the bore passage in agreement with earlier findings. Velocity measurements were conducted at high frequency (200 Hz). In breaking bores, the ensemble averaged data exhibited large velocity reversals near the bed beneath the bore front and in its wake, whereas, in undular bores, a lesser deceleration was observed. The vertical velocity data trend closely followed the water depth time derivative for both breaking and undular bores. Overall, the velocity measurements displayed large velocity fluctuations during the passage of the bore which were believed to induce strong turbulent mixing. The turbulence was further investigated by a two point correlation technique to estimate both turbulent integral time and length scales. The turbulent integral length scales values were similar in the steady and unsteady flows, whereas the turbulent time scales were larger in the unsteady flow. The experiments were limited by the instrumentation since the ADV systems interacted with each other and lacked accuracy for measurements performed in the near vicinity of physical boundaries.A numerical investigation was then performed using the computational fluid dynamics (CFD) ii code Thétis developed in the I2M laboratory of the Université de Bordeaux. Numerical simulations reproduced experiments performed in laboratory prior to this study (Chanson, 2010a,b). The fluid was modelled by the Navier-Stokes equations in their incompressible two-phase form. The turbulence model used a large eddy simulation and the interface air-water was tracked by using a volume of fluid model. Two dimensional and three dimensional simulations were performed to study the comp...

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“…4(a)), the glass material was characterised by a regular grain size centred around a radius of 60 µm. The Navier Stokes resolution [16] of the microstructure evolution during sintering using the Front Tracking approach is presented in figure 5. The increase of the contact radius between particles until the contact coalescence as well as the pore closing is successfully modelled.…”

Section: Modelling Of a Real Arrangement Of Particles Extracted From mentioning

confidence: 99%

Towards 3D simulation of sintering processes

Bordère¹,

Bernard²,

Vincent³

et al. 2007

WIT Transactions on Engineering Sciences, Vol 57

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The Monte Carlo approach based on minimisation of a potential including interface and volume energies has been implemented in the framework of a Eulerian interface tracking method in order to deal with 3D sintering of complex powder compacts. First applied to the unique spherical particle system, these new developments lead to a surface tension-induced pressure close to that theoretically given by Laplace's law. The accuracy of this result is largely improved compared to those given by a classical fluid mechanics computation using the front tracking method. Our progress towards 3D modelling of sintering for realistic systems is illustrated by the computed stress gradients induced by surface curvature gradients within a small set of particles extracted from X-ray computed micro-tomography images of a real sample.

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A One-Cell Local Multigrid Method for Solving Unsteady Incompressible Multiphase Flows

Cited by 66 publications

References 39 publications

Numerical Simulation of Gas-Jet Wiping in Steel Strip Galvanizing Process

Numerical Simulation of Gas-Jet Wiping in Steel Strip Galvanizing Process

Effects of tidal bores on turbulent mixing: a numerical and physical study in positive surges

Towards 3D simulation of sintering processes

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