Open Access

ARTICLE

G.Pétré¹, K.Tshinyama, A. Azouni², S. Van Vaerenbergh¹
FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.1, pp. 1-10, 2008, DOI:10.3970/fdmp.2008.004.001
Abstract This study illustrates a relevant and practical method to determine the effective surface tension gradient in a layer subjected to a lateral temperature difference. In general, this can be hardly performed in situ without perturbing the flow. For this reason we rely on an indirect determination approach. A simple model is developed that relates the surface tension gradient to other quantities that can be measured without introducing significant disturbances in the system. Measurements of these quantities are performed in a set-up where the flow corresponds with a good approximation to a one-dimensional model. A previously used More >

View

1403

Download

1117

Open Access

ARTICLE

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 More >

View

1645

Download

1144

Open Access

ARTICLE

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 More >

View

1682

Download

1233

Open Access

ARTICLE

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 More >

View

1603

Download

1221

Open Access

ARTICLE

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. More >

View

1573

Download

1111

Open Access

ARTICLE

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 >

View

1676

Download

1168