Implementing Holographic Microscopy for Studying Turbulence above Biological and Geological Surfaces

Jiarong Hong, Benjamin Mayhugh Assistant Professor, Department of Mechanical Engineering and St. Anthony Falls Laboratory, College of Science and Engineering, University of Minnesota

Naturally-formed biological and geological surfaces provide a well of inspiration for fluid engineering applications. Our research work is focused on understanding the connection between turbulent flow and the formation and the function of various types of surface roughness. Specifically, we are investigating experimentally on how the variation of shark skin denticle morphology affects near-wall hydrodynamics and how the small-scale dynamics involved in turbulence-sediment interaction contributes to the formation of different bedforms. Our experiments use digital holographic microscopy, which is a 3D imaging technique suitable for quantifying fluid dynamics with high resolution at small scales. In this talk, I will present a general framework of this research, a description of our experimental setup and some preliminary data, followed by a discussion on challenges and future work.