Biomedical subjects

Jonathan Chin

Publications and source records attributed to Jonathan Chin.

5 recordsLinked to original sources

PubMed2005

WEDS: a Web services-based environment for distributed simulation.

Web services have the potential to radically enhance the ability of researchers to make use of distributed computing resources, but jargon and a plethora of standards make their use almost impossible for the scientist without prior experience of the necessary technologies. A powerful and simple WSRF-based middleware scheme is presented, designed to let scientists remotely deploy single or multiple instances of a pre-existing code across multiple resources, and giving steering, visualization and workflow functionality with only simple modifications to program code. It is hoped that the development and implementation of such a toolkit will be relevant not only to the problem of deploying workstation-class codes in real time, but also the move towards more tractable alternatives to the Globus toolkit for deployment of processes in a high-performance computing environment.

Computer Simulation↗

PubMed2005

Large-scale lattice Boltzmann simulations of complex fluids: advances through the advent of computational Grids.

During the last 2.5 years, the RealityGrid project has allowed us to be one of the few scientific groups involved in the development of computational Grids. Since smoothly working production Grids are not yet available, we have been able to substantially influence the direction of software and Grid deployment within the project. In this paper, we review our results from large-scale three-dimensional lattice Boltzmann simulations performed over the last 2.5 years. We describe how the proactive use of computational steering, and advanced job migration and visualization techniques enabled us to do our scientific work more efficiently. The projects reported on in this paper are studies of complex fluid flows under shear or in porous media, as well as large-scale parameter searches, and studies of the self-organization of liquid cubic mesophases.

Computer Graphics↗

PubMed2004

Structural and dynamical characterization of Hele-Shaw viscous fingering.

Viscous fingering occurs in the interfacial zone between two fluids confined between two plates with a narrow gap (Hele-Shaw geometry) when a highly viscous fluid is displaced by a fluid with relatively low viscosity. Using a mesoscopic approach--the lattice Boltzmann method--we investigate the dynamics of spatially extended Hele-Shaw flow under conditions corresponding to various experimental systems by tuning the 'surface tension' and the reactivity between the two fluids. We discuss the onset of the fingering instability (dispersion relation), analyse the structural properties (characterization of the interface) and the dynamical properties (growth of the mixing zone) of the Hele-Shaw systems, and show the effect of reactive processes on the structure of the interfacial zone.

Journal Article↗

PubMed2002

Lattice Boltzmann study of spinodal decomposition in two dimensions.

A lattice Boltzmann model using the Shan-Chen prescription for a binary immiscible fluid is described, and the macroscopic equations obeyed by the model are derived. The model is used to quantitatively examine spinodal decomposition of a two-dimensional binary fluid. This model allows examination of the early-time period corresponding to interface formation, and shows agreement with analytical solutions of the linearized Cahn-Hilliard equation, despite the fact that the model contains no explicit free-energy functional. This regime has not, to the knowledge of the authors, been previously observed using any lattice Boltzmann method. In agreement with other models, a scaling law with the exponent 2/3 is observed for late-time domain growth. Breakdown of scaling is also observed for certain sets of simulation parameters.

Journal Article↗

PubMed2002

Lattice Boltzmann simulation of the flow of binary immiscible fluids with different viscosities using the Shan-Chen microscopic interaction model.

We present a lattice Boltzmann study of the flow of a binary fluid where the fluid components have different viscosities. For this purpose, a microscopic interaction model (due to Shan & Chen) is used. The model is validated for Poiseuille flow of layered immiscible binary fluids and the dispersion of a capillary wave. We then study the unstable displacement of a viscous fluid by a less viscous fluid in a two-dimensional channel. Although a finger-like structure was observed in many simulations, it is not clear if this structure was produced due to viscous fingering or due to other effects.

Colloids↗