Tuesday 10 Mar 2015: What lies beneath? Surface-subsurface interactions in fluvial and coastal environments
Professor Dubravka Pokrajac - University of Aberdeen
Harrison 170 14:00-15:00
Turbulent boundary layer flow in the natural environment commonly occurs over permeable layers such as river beds and coastal beaches. The fluids within these permeable layers exchange mass, momentum and any dissolved or suspended substance with the surface flow. These exchange processes, collectively called surface-subsurface interactions, affect flow and therefore sediment transport close to the bed. The details of the complex mechanisms of surface-subsurface interactions are not yet fully understood, primarily due to the difficulties in measuring flow velocities within the permeable materials. However, in the past couple of decades non-intrusive experimental technologies such as Particle Image Velocimetry and Laser-Induced Fluorescence have made it possible to measure the detailed flow field above and within porous materials that are exposed to turbulent flow over their surface. This seminar presents a series of experimental and numerical results which clarify the role of surface-subsurface interactions in the fluvial and coastal environment.