Abstract:
This talk will focus on recent advances in characterizing turbulence spectra and their implications for environmental flows. I will first present a theoretical formulation that extends the generalized velocity spectrum model to reproduce the debated -1 spectral scaling, linking scale-invariant eddy clustering to observed features in atmospheric boundary layers and riverine flows. Validation against coastal ABL and river datasets shows that the model captures this regime and identifies when it is absent. Next, I will explore clay-laden flows using clear laponite suspensions, which enable direct flow visualization and reveal that even low concentrations can drive fundamental transitions: flows evolve from turbulence resembling clear water to plug-dominated regimes with strong turbulence attenuation and elongated coherent motions characterized by enhanced streamwise velocity fluctuations and reduced vertical counterparts. Finally, I will discuss the role of extracellular polymeric substances (EPS), examined through xanthan gum suspensions, which at concentrations far below those of clays suppress turbulence, reorganize coherent structures, and promote plug-like velocity profiles. These insights are instrumental for refining turbulence models to account for particle and polymer effects, with broad implications for predicting flow structure, transport, and deposition in natural aquatic systems.
Bio:
Leonardo Chamorro is a Professor and Associate Head of Undergraduate Programs in the Department of Mechanical Science and Engineering. He also holds affiliations with the Departments of Civil and Environmental Engineering, Aerospace Engineering, and Earth Science and Environmental Change. His research spans turbulence, particle dynamics, boundary-layer processes, turbulence–structure interaction, aerodynamics, wind and marine energy, and advanced flow diagnostics. Dr. Chamorro has authored nearly 160 peer-reviewed articles and participated in over 150 presentations at international symposia. He previously served as scientific chair for Energy, Electrical Engineering, Electronics, and Mechanics (W&T7) at the Research Foundation Flanders (FWO) in Belgium. He is currently an Associate Editor for the Journal of Renewable and Sustainable Energy, Frontiers in Energy Research, and the Journal of Energy Engineering. He leads the Renewable Energy and Turbulent Environment group, which uses state-of-the-art experimental approaches, including 2D/3D particle image velocimetry, computer vision, and 3D particle tracking velocimetry.