Open Access

ARTICLE

Edwin Jim ´enez¹, Mark Sussman², Mitsuhiro Ohta³
FDMP-Fluid Dynamics & Materials Processing, Vol.1, No.2, pp. 97-108, 2005, DOI:10.3970/fdmp.2005.001.097
Abstract The aim of this paper is to utilize a numerical model to compute bubble motion in quiescent Newtonian and viscoelastic liquids. For our numerical method, we use a coupled level set and volume-of-fluid method with a second order treatment for the jump conditions related to surface tension. We investigate axisymmetric gas-liquid systems with large density and viscosity ratios as well as buoyancy-driven flows with complex changes in topology. We present comparisons to previous computational results as well as experimental results. More >

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1139

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ARTICLE

Cosmina S. Hogea¹, Bruce T. Murray¹, James A. Sethian^2,3
FDMP-Fluid Dynamics & Materials Processing, Vol.1, No.2, pp. 109-130, 2005, DOI:10.3970/fdmp.2005.001.109
Abstract A computational framework for simulating growth and transport in biological materials based on continuum models is proposed. The advantages of the finite difference methodology employed are generality and relative simplicity of implementation. The Cartesian mesh/level set method developed here provides a computational tool for the investigation of a host of transport-based tissue/tumor growth models, that are posed as free or moving boundary problems and may exhibit complicated boundary evolution including topological changes. The methodology is tested here on a widely studied "incompressible flow" type tumor growth model with a numerical implementation in two dimensions; comparisons with results obtained from a… More >

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1580

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ARTICLE

O.M. Lavrenteva¹, D. Tsemakh, A. Nir
FDMP-Fluid Dynamics & Materials Processing, Vol.1, No.2, pp. 131-152, 2005, DOI:10.3970/fdmp.2005.001.131
Abstract We have studied the motion of a drop, induced by the internal secretion of a surface-active substance, in the vicinity of solid walls or non-deformable liquid-liquid interface under micro-gravity conditions. The secreted substance renders a non-uniform distribution of surfactant along the outer surface that, in turn, results in interfacial stress variation that ultimately leads to a surface motion and to locomotion of the drop. Cases of plane and spherical boundaries have been considered as well as cases of linear and non-linear dependence of the interfacial tension on concentration of surfactant. The dependence of the drop migration velocity on the location… More >

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1136

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N.I. Wakayama¹, D.C. Yin², J.W. Qi³
FDMP-Fluid Dynamics & Materials Processing, Vol.1, No.2, pp. 153-170, 2005, DOI:10.3970/fdmp.2005.001.153
Abstract The production of crystals of adequate size and high quality is the "bottleneck'' for three-dimensional structure analysis of protein crystals. In this work, in order to shed additional light on the (still controversial) beneficial effect of microgravity on crystal growth, we focus on recent advanced experimental and theoretical research about the effects of buoyancy-driven convection on protein crystallization. In the light of the numerical studies the following major outcomes can be highlighted: (1) when the crystal size exceeds several dozens of µm, buoyancy-driven convection dominates solute transport near the growing crystal and the crystal growth rate becomes larger than that… More >

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1110

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ARTICLE

Marcello Lappa¹
FDMP-Fluid Dynamics & Materials Processing, Vol.1, No.2, pp. 171-188, 2005, DOI:10.3970/fdmp.2005.001.171
Abstract The paper presents a comparative and critical analysis of some theoretical/experimental/numerical arguments concerning the possible stabilization of the surface-tension-driven (Marangoni) flow in the Floating Zone technique and in various related fluid-dynamic models. It is conceived as a natural extension of the focused overview published in Cryst. Res. Tech. 40(6), 531, (2005) where much room was devoted to discuss the intrinsic physical mechanisms responsible for three-dimensional and oscillatory flows in a variety of technological processes. Here, a significant effort is provided to illustrate the genesis of possible control strategies (many of which are still in a very embryonic condition), the underlying… More >

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1128

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D. E. Melnikov¹, V. M. Shevtsova²
FDMP-Fluid Dynamics & Materials Processing, Vol.1, No.2, pp. 189-200, 2005, DOI:10.3970/fdmp.2005.001.189
Abstract Buoyancy-driven convective flows are numerically analyzed in a cubic enclosure, containing a liquid subjected to a temperature difference between opposite lateral walls; all other walls are thermally insulated. The stationary gravity vector is perpendicular to the applied temperature gradient. The steady flow patterns are investigated within the framework of a liquid particles tracing technique. Three tracing techniques are compared: the first, based on a trilinear interpolation of the liquid velocity defined on the computational grid and an eighth order in time Runge-Kutta method; the second and the third, using a resampling the velocity field on a new approximately twice finer… More >

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1129