The present contribution provides a fluid dynamic and thermal characterization of structured representatives of open-cell foams. Geometric and analytic methods as well as numeric simulations serve as tools for technical optimization. Three different types of structures are analyzed: a simple cubic structure, a Kelvin cell structure, and a diamond structure. These structures are used as carrier structures in catalysis and make up the inner part of a reactor which is built in its entirety using a 3D printing or additive manufacturing method (here: selective electron beam melting). To provide optimal conditions for the strong endothermic, catalytic and gas releasing reaction, it is important, to ascertain geometric properties like porosity and specific surface area in addition to fluid dynamic properties. Using geometric modelling analytic equations will be presented that for the first time allows us to determine solid volume and surface area of a unit cell based only on strut length and strut diameter. The manifold potential of the analytic equations is shown using two examples. Strut length and diameter can be determined in order to manufacture different types of structures with equal porosity or specific surface area. It is also possible to maximize the specific surface area for a given porosity. The open-source framework OpenFOAM solves the governing thermo-fluid dynamic equations. This thesis compares the results of the simulation of a single unit cell and of a whole reactor as well as assesses the pressure drop, among other things, as a characteristic size. Dimensionless numbers serve as comparative tools. It can be shown that the pressure drop of the whole reactor can only partly be determined from the pressure loss of a single unit cell. Furthermore, for the first time frequency distributions of velocity and temperature of the different structures are compared. This way the diamond structure is clearly identified as the structure, which provides the best conditions for a catalytic reaction. Concluding the ...


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    Titel :

    Thermo-fluid dynamic characterization and technical optimization of structured open-cell metal foams by means of numerical simulation ; Thermofluiddynamische Charakterisierung und technische Optimierung strukturierter, offener Metallschäume mittels numerischer Simulation


    Beteiligte:

    Erscheinungsdatum :

    2015-01-01


    Medientyp :

    Hochschulschrift


    Format :

    Elektronische Ressource


    Sprache :

    Englisch



    Klassifikation :

    DDC:    629