MAE Department - PG seminar - Almost linear models of wall turbulence
Turbulence is often associated with stochastic processes for which statistical energy transfers provide fundamental understanding. Turbulent flows, however, are high-dimensional deterministic systems, which are quite accurately represented by the Navier—Stokes equations. I will present turbulence from dynamical systems perspective and show that despite strong nonlinearities, these systems are highly influenced by linear terms. With turbulent channel flow as a case study, I will further show that there is convincing evidence to support simplifying the nonlinear terms and obtain almost linear models of wall turbulence. I will present ways to refine such linear models so they can be used for the estimation and control of energy-containing eddies. I will end with motivating examples from my research on canopy flows and wind-turbine wakes.
Dr. Vikrant Gupta is currently a Research Associate Professor at the Southern University of Science & Technology, China, where his research is on applying data-driven and dynamical systems tools to study complex flows. The areas of application include wall turbulence, wind and tidal energy and low-emissions gas turbines. He has obtained his PhD from the University of Cambridge for which he was awarded a Dorothy Hodgkin Postgraduate Award and his bachelor’s and master’s degrees from Indian Institute of Technology Madras. He has published 10 Journal of Fluid Mechanics articles in the last five years and has won two NSFC grants for his research on wall turbulence and wind energy.