View Item 
        •   Utrecht University Student Theses Repository Home
        • UU Theses Repository
        • Theses
        • View Item
        •   Utrecht University Student Theses Repository Home
        • UU Theses Repository
        • Theses
        • View Item
        JavaScript is disabled for your browser. Some features of this site may not work without it.

        Browse

        All of UU Student Theses RepositoryBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

        The effect of breaking-induced turbulence on sediment entrainment in the surfzone

        Thumbnail
        View/Open
        MSc thesis Winnie de Winter_final.pdf (1.659Mb)
        Publication date
        2014
        Author
        Winter, W. de
        Metadata
        Show full item record
        Summary
        In the surfzone sediment is suspended into the water column both due to turbulence generated at the bottom boundary layer (BBL) and turbulence generated at the surface boundary layer (SBL). In this research the impact of the source of turbulence under breaking waves on sediment suspension in the surfzone is investigated using the Turbulent Kinetic Energy (TKE) and the Suspended Sediment Concentration (SSC). The TKE was measured at three different heights above the bed. SSCs were measured at 3, 5, or 7 different heights above the bed depending on the cross-shore location. The Feddersen and Williams (2007) differencing method was used to derive turbulence from three dimensional velocity data. Both the TKE and SSC are related to cross-shore position. Under breaking waves the TKE increases towards the water surface, which indicates that the surface generated turbulence is dominant over turbulence generated at the sea bed. Conditions with non-breaking waves show an increase of TKE towards the sea bed, indicating the dominance of the bottom boundary layer in the generation of turbulence in the water column. Breaking-induced turbulence increases the near bed SSC and increases the vertical mixing of sediment in the water column. Despite the fact that both the TKE and SSC are related to cross-shore position and thus the degree of breaking waves, there is no clear relation between the short-wave energy dissipation and the percentage of TKE events which can be related to SSC events.
        URI
        https://studenttheses.uu.nl/handle/20.500.12932/16204
        Collections
        • Theses
        Utrecht university logo