Behavior of particles in turbulence over a wavy wall
Abstract
A fluid flowing over a wavy boundary creates turbulence which is different from the flow over a flat wall. This wave-induced variation of flow structures is of great importance for many engineering fields such as fluvial and coastal researches. In this study, turbulent flow over a wavy wall was investigated by direct numerical simulation (DNS). The virtual boundary method proposed by Goldstein et al. (1994) is applied to impose the no-slip condition at immersed boundary. To begin with, parameters for the virtual forcing are determined by the stability limit (Lee, 2003), and measurements of turbulence by laser Doppler velocimetry (Nakagawa et al., 2003) are used for the validation of the virtual boundary method used in this simulation. Also, we focused on the differences between turbulence generated at a wavy boundary and one at a flat wall such as friction factors, velocity fluctuations, and vortical structures associated with shear layers that form behind the wave. More importantly, investigations of the behavior of Lagrangian fluid and of heavy particle in the flow over a wavy wall are carried out because of their importance in understanding of the mechanism of sedimentation and pollutant transport. Detailed statistics and relevant physical interpretation will be presented in the meeting.
- Publication:
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APS Division of Fluid Dynamics Meeting Abstracts
- Pub Date:
- November 2011
- Bibcode:
- 2011APS..DFDA12005L