Institute for Hydromechanics

Shallow wake formed after porous structures

  • contact: Wernher Brevis, Frederik Prinz
  • project group:

    EFM

  • enddate: 2011

The global aim of the project is to gain fundamental understanding of the flow structure and mass transport effects caused by porous bodies in shallow flows. The project includes the characterization of the far field structures forming the wake-instability, the characterization of the three-dimensional structure in the near field, as well as the small-scale structures within the porous body. The experimental parameters include several ranges of porosity, geometrical length-scales, and Shallowness and Reynolds numbers. For the scales inside the eddy containing energy part of the spectra, the turbulent characteristics and mass transport effects will be described. Even though the research is focused on fundamental fluid mechanics issues, the understanding of this flow has various applications such as the description and prediction of the role on mass and sediment transport produced by vegetation clusters or to improve the design of pile-groups for bridge construction. In addition, the output of this research can be used to describe the organic-pollution patterns and mixing rates characteristic of fish-cages in coastal areas.
The measuring techniques include surface Particle Tracking Velocimetry (PTV) for the velocity measurement of the large-scale structures and Planar Concentration Analysis (PCA) / Laser Induced Fluorescence (LIF) for concentration measurements. For the small scale structures Particle Image Velocimetry (PIV) and PTV measurements are used.