Plenoptic particle image velocimetry was used to perform instantaneous three-dimensional velocity measurements in the near wake of a wall-mounted hemispherical roughness element at a Reynolds number (based on roughness height) of 4.57×103 and boundary layer to roughness height ratio of 2.4. The experiment was performed in a refractive index matched flow facility to mitigate laser reflections from the hemispherical surface. Data gathered from this experiment represented one of the first applications of plenoptic particle image velocimetry. The ensemble-averaged flow is characterized by a separated shear layer and a symmetric recirculation region. In the instantaneous three-dimensional velocity fields, a separated shear layer and recirculation region, both with asymmetric characteristics, are present. Additionally, arch vortices are found that are detached to the hemispherical surface. The proper orthogonal decomposition was applied to both the three-dimensional velocity and three-dimensional vorticity fields with the goal of identifying the structures created by the hemisphere. The velocity modes showed features associated with the overall flow, whereas the vorticity modes were largely associated with the near wake. The most energetic proper orthogonal decomposition modes showed fluctuations in the boundary layer and recirculation region, as well as suggested the existence of shed arch-shaped vortices.


    Zugriff

    Zugriff über TIB

    Verfügbarkeit in meiner Bibliothek prüfen

    Bestellung bei Subito €


    Exportieren, teilen und zitieren



    Titel :

    Volumetric Velocity Measurements in the Wake of a Hemispherical Roughness Element



    Erschienen in:

    Erscheinungsdatum :

    2017




    Medientyp :

    Aufsatz (Zeitschrift)


    Format :

    Print


    Sprache :

    Englisch


    Schlagwörter :

    Klassifikation :

    BKL:    55.50 Luftfahrzeugtechnik / 55.60 Raumfahrttechnik / 55.60 / 50.93 / 55.50 / 50.93 Weltraumforschung
    Lokalklassifikation TIB:    770/7040




    Volumetric Velocity Measurements in the Wake of a Hemispherical Roughness Element

    Johnson, Kyle C. / Thurow, Brian S. / Kim, Taehoon et al. | AIAA | 2017


    Volumetric Velocity Measurements in the Vicinity and Wake of Rain Drops

    Hortensius, Ruben / Troolin, Daniel R. / Mallery, Kevin | AIAA | 2021


    VOLUMETRIC VELOCITY MEASUREMENTS IN THE VICINITY AND WAKE OF RAIN DROPS

    Hortensius, Ruben / Troolin, Daniel R. / Mallery, Kevin | TIBKAT | 2021


    NO PLIF Study of Hypersonic Transition over a Discrete Hemispherical Roughness Element

    Danehy, Paul / Bathel, Brett / Ivey, Christopher et al. | AIAA | 2009