Convection and diffusion in a micro flow injection system

E.B. van Akker

    Research output: ThesisPhD Thesis - Research UT, graduation UT

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    Much has been written about the theoretical background of Flow Injection Analysis (FIA) systems. Until now the prediction of the dispersion in a FIA system was restricted to the use of simple formulae or two-dimensional numerical models. Through recent developments in computer hardware and, at the same time, the development of efficient computational fluid dynamics software it is possible, with the use of a three dimensional model (based on the Navier-Stokes equations), to make a 1 to 1 translation between experimental systems and systems based on numerical calculations. A 1 to 1 translation means that only (fundamental) parameters are necessary in the numerical description without the need for fit or match factors. All the known phenomena, such as convection and diffusion, are incorporated in this description. The fundamental parameters in this thesis are: the concentrations, the diffusion coefficients, the geometry, the flow rates and in case of a reaction, the reaction constant, the reaction equation and reaction order. Next to these macro FIA systems the micro FIA systems are emerging. These systems have many advantages compared to the traditional macro systems. Two examples are: a considerable reduction in analyte consumption and the development of portable systems. One disadvantage of the current microsystems, is the expensive development. It would be very helpful, money wise, if numerical calculations could be used for the development of an optimal microsystem. In this thesis the results of a three dimensional numerical model, based on the Navier-Stokes equations, are compared with experimental results. This has been done for channels of different geometries, different flow rates and a simple reaction.
    Original languageUndefined
    Awarding Institution
    • University of Twente
    • van der Linden, W.E., Supervisor
    • Bos, M., Advisor
    Award date1 Oct 1999
    Place of Publicationenschede
    Print ISBNs90-3651339-1
    Publication statusPublished - 1 Oct 1999


    • IR-8859
    • METIS-104983

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