L. Bennamoun¹, A. Belhamri²

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.4, pp. 221-230, 2008, DOI:10.3970/fdmp.2008.004.221

Abstract This work focuses on tyipical heat and mass transfer phenomena during the processing of products in the context of the packed-bed drying method (products arranged in thick layers into dryers working in forced convection mode). The dryers are modeled as porous media at the macroscopic level. The simulations are carried out using the mass, momentum (written in the framework of the Darcy's law approximation) and energy equations applied for the different components. A diffusion model based on Fick's law is also used to take into account the drying kinetics. This approach allows monitoring of the variations of humidity and temperature… More >

A.A. Ivanova¹, V.G. Kozlov^1,2,3, D.A. Polezhaev¹, D. Pareau³, M. Stambouli³

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.3, pp. 211-220, 2008, DOI:10.3970/fdmp.2008.004.211

Abstract The problem for the optimization of mass-transfer on the interface of two immiscible liquids by means of vibrational hydromechanics is studied experimentally. A new vibrational cell of Lewis's type expressly conceived for such purposes is described. Flow is generated by activators in the form of disks inducing translational axial oscillations near the opposite end faces of the cavity. It is shown that such vibrating disks can lead to the onset of a large-scale toroidal whirlwind effectively mixing the liquid throughout the volume. According to the experiments, in particular, axisymmetrical radial flows are generated on both sides of the horizontal liquid… More >

K. Achoubir¹, R. Bennacer², A. Cheddadi¹, M. El Ganaoui³, E. Semma^3,4

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.3, pp. 199-210, 2008, DOI:10.3970/fdmp.2008.004.199

Abstract The present work is devoted to the numerical investigation of the interaction between thermal and solutal convection in enclosures used for modeling directional solidification. The full transient Navier--Stokes, energy and species conservation equations are solved numerically by using finite volumes technique. More >

Sayavur I. Bakhtiyarov¹, Dennis A. Siginer²

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.3, pp. 163-184, 2008, DOI:10.3970/fdmp.2008.004.163

Abstract This article has no abstract. More >

Pravin Subramanian¹, Abdelfattah Zebib¹

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.3, pp. 139-162, 2008, DOI:10.3970/fdmp.2008.004.139

Abstract A theoretical and computational study of solutocapillary driven Marangoni instabilities in small spherical shells is presented. The shells contain a binary fluid with an evaporating solvent. The viscosity is a strong function of the solvent concentration, the inner surface of the shell is assumed impermeable and stress free, while non-linear boundary conditions are modeled and prescribed at the receding outer boundary. A time-dependent diffusive state is possible and may lose stability through the Marangoni mechanism due to surface tension dependence on solvent concentration (buoyant forces are negligible in this micro-scale problem). The Capillary number (Ca) provides a measure of the… More >

I. Ueno¹, T. Kishida²

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.1, pp. 55-60, 2008, DOI:10.3970/fdmp.2008.004.055

Abstract Phenomenon known as `tears of wine' arises on an inclined plate partially submerged in a bulk of alcohol-water mixture. This phenomenon apparently exhibits a periodic ordered structure, the flow field itself evolves quite complex feature; especially in the vicinity of the tear. In the present study, the authors paid their special attention to this unique, complex flow field of O(1 mm) with deformable surface. The flow pattern and the spatio-temporal particle behavior in the tear were reconstructed by applying three-dimensional particle tracking velocimetry (3-D PTV). More >

V. Shevtsova^1,2, A. Mialdun¹, C. Ferrera^1,4, M. Ermakov^3,4, J. M. Montanero⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.1, pp. 43-54, 2008, DOI:10.3970/fdmp.2008.004.043

Abstract Dynamic free surface deformations induced by buoyant and thermocapillary convection in liquid bridges of 5cSt silicone oil are studied experimentally and numerically. The experiments are performed in ground conditions and static deformation is unavoidable. Convective motion starts in the liquid bridge as soon as ΔT ≠ 0 and initially leads to a stationary dynamic deformation of the free surface. Oscillatory motion starts at a critical value of ΔT and causes oscillations of the interface. The final supercritical shape of the free surface is a result of the static shape with superimposed subcritical stationary and oscillatory dynamic deformations. All these contributions… More >

Shuwang Li¹, Xiangrong Li¹, John Lowengrub^1,2, Martin Glicksman³

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.1, pp. 27-42, 2008, DOI:10.3970/fdmp.2008.004.027

Abstract In this paper, we suggest a deterministic mechanism for the generation and development of side-branches in dendritic growth. The present authors investigated recently [Glicksman, Lowengrub, and Li (2006)] the existence of such a deterministic branching mechanism induced through the Gibbs-Thomson-Herring (GTH [Herring (1951)]) anisotropic capillary boundary condition. In this paper, we focus our study on an anisotropic kinetic boundary condition. We develop and apply accurate boundary integral methods in 2D and 3D, in which a time and space rescaling scheme is implemented, that are capable of separating the dynamics of growth from those of morphology change. Numerical results reveal that… More >

I. Ueno¹, T. Konisho², T. Kawase³, T. Watanabe⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.1, pp. 21-26, 2008, DOI:10.3970/fdmp.2008.004.021

Abstract The present authors carried out an experimental study with a special interest upon the dynamics of the fluid in the vicinity of the boundary line of three phases; solid-liquid-gas interface, which is so-called `contact line.' The moving droplet on the solid substrate is accompanied with the movement of the boundary line of three phases; solid-liquid-gas interface, which is so-called macroscopic 'contact line.' Existing studies have indicated there is a thin liquid film known as 'precursor film' ahead the contact line of the droplet. In the present study the precursor film was detected by applying conventional ellipsometer, and its existing length… More >

Thomas Boeck¹, Alexander Nepomnyashchy^2,3, Ilya Simanovskii²

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.1, pp. 11-20, 2008, DOI:10.3970/fdmp.2008.004.011

Abstract Anticonvection in a two-layer system of mercury and water is studied using three-dimensional direct numerical simulations with a Fourier-Chebyshev spectral method. The two fluid layers have equal thicknesses and are uniformly heated from above. Interface deformations and surface tension gradients are neglected. The quiescent state is replaced by steady hexagons upon increasing the heating from above. We investigate the destabilization of this primary convective pattern in a small and in a large computational domain upon increasing the temperature difference across the two fluid layers. For the large domain the convection cells become disordered at about twice the critical temperature difference… More >