Submitted to: Analytical Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/29/2007
Publication Date: 4/1/2007
Citation: Brewster, J.D. 2007. Lattice boltzmann simulations of three dimensional fluid flow on a desktop computer. Analytical Chemistry. 79:2965-2971. Interpretive Summary: Rapid assay methods now under development will be able to detect a wide variety of pathogens and toxins in a single sample using a miniaturized array of biosensors. These methods rely on a series of devices and operations to transform a raw sample containing several ounces of food into a single drop of liquid, free of particles and other interfering substances, for input to the biosensor. Optimizing these operations by building and testing devices is a tedious and lengthy process. Computer simulations of the sample processing and detection operations can significantly speed development of assay systems. This work describes a general purpose, easy to use simulation system based on the lattice-Boltzmann method, a recent technique for modeling liquid flow. I have developed an algorithm which increases calculation speed by a factor of 100, and developed a new way to handle diffusion along with flow. This allows large scale, three-dimensional simulations to be performed on a desktop computer, rather than the supercomputers previously needed for such calculations. This will significantly enhance the development of the next generation of sample processing and detection systems needed for rapid detection of foodborne disease and bioterror threats.
Technical Abstract: The lattice-Boltzmann (LB) method is a cellular automaton approach to simulating fluid flow with many advantages over conventional methods based on the Navier-Stokes equations. It is conceptually simple, amenable to a wide array of boundary conditions, and readily adapted to handle thermal, density, miscibility, and other effects. The LB approach has been used to model a number of fluid systems of interest to analytical chemists, including chromatography columns, micromixers, and electroosmotic pumps. However, widespread use of this tool has been limited since virtually all large-scale 3D simulations in the literature have been executed on supercomputers. This work demonstrates that such simulations can be executed in reasonable periods of time (hours) on available desktop computers using readily available software. Several improvements are described which enhance the utility of the LB approach, including an algorithm for speeding common calculations by two orders of magnitude and a new scheme for handling convection-diffusion equations of interest in electrochemical and surface reaction studies.