Author(s): Qian Liao; Binbin Wang; Harvey A. Bootsma
Linked Author(s):
Keywords: In situ PIV; Turbulence; Propeller wash; Sediment resuspension; Environmental hydraulics
Abstract: Small-scale hydrodynamics in aquatic systems, i. e., rivers, lakes, oceans and wetlands, is an important factor that controls environmental transport processes, especially those near a physical interface such as the water-sediment, air-water, and water-vegetation interface. Traditional turbulent velocity measurements in field studies are usually limited to one point or along a line in space, and they lack the resolution to characterize turbulence structures at dissipative scales, which are critical parameters that determine the flux of dissolved pollutants, nutrients and gases. We have developed a novel self-contained Underwater Miniature Particle Image Velocimetry (UWMPIV) system to facilitate research on small-scale turbulence in the vicinity of environmental interfaces. Here we present an application of the UWMPIV system to study sediment resuspension under propeller wash in US Navy harbors. The in situ PIV measurement enabled us to visualize sediment resuspension and erosion processes with high spatial and temporal resolutions. The critical shear stress could be estimated by direct observing PIV images and identifying the moment when sediment resuspension started.
Year: 2013