Sediment dynamics - Fluid and sediment bed interactions. What roles do fluid infiltration and grain shape play? - 3D numerical flume tank experiments

• Applicant: Dr. Gerhard Bartzke
• Subject Area: Palaeontology ; Geodesy, Photogrammetry, Remote Sensing, Geoinformatics, Cartography
• Term: from 2014 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 258669118

This proposal was inspired by the inherent limitations in the quantification of the physical parameters (e.g., flow speed and grain shape) controlling sediment-fluid interactions in the direct vicinity of the sediment water interface and in the interior of a sediment bed. For investigation of the processes influencing the erosion characteristics of sediments beds, researchers commonly tested the transport behavior sediment beds empirically using laboratory flume tanks or in situ field investigations. However, a precise quantification of the processes occurring in the direct vicinity and in the interior of the sediment body, such as the fluid infiltration rates into the sediment bed, is difficult when using these techniques. Therefore, the physical processes in the interior of a sediment bed require further investigation. With a focus on the physical processes, occurring in the direct vicinity and in the interior of a sediment bed, the overall goal of this proposed research is to identify and quantify the role of fluid infiltration and grain shape variations on the transport behavior of sediments beds using 3D numerical simulations. It is hypothesized that: (1) the grain shapes found in natural sediment beds effect the amount of flow available to infiltrate into a sediment bed. (2) the textural bed composition (round versus non-round shapes) controls the inflow rates into a sediment bed and, hence, the erosion characteristics, and (3) natural grain shapes in sediment beds influence the erosion characteristics of sediment beds. By the use of the numerical Smooth Particle Hydrodynamics (SPH) method, uniform sediment beds composed of different grain shapes, will be tested in a 3D numerical flume tank under different current velocities. Physical features, such as the role of fluid inflow and grain shape variations on the transport characteristics will be measured at high resolution in the direct vicinity and in the interior of the sediment beds.

• DFG Programme: Research Grants