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PDEs & Applications Seminar

Tuesday, March 5th, 2024

Time: 9:30 a.m.  Place: Jeffery Hall, Room 319 (Via Zoom)

Speaker: Ugo Piomelli (Queen’s)

Title: Numerical simultions of turbulence

Abstract: Turbulence has been described as the last unsolved problem of classical mechanics. It is a phenomenon that affects most fluid flows in engineering and the natural sciences, and its understanding is crucial to improve the design of ship, aircraft, and cars, the prediction of weather patterns, or the impact of environmental changes. Turbulence is a multiscale phenomenon, and is neither entirely deterministic, nor completely stochastic. While statistical mechanics tools can be used to predict the behaviour of the small and intermediate-sized motions, no theory has fully explained the behaviour of the larger ones, which depend strongly on the boundary conditions. Yet, it is the larger scales that drive the momentum and energy transport.

The numerical solution of the equations of motion, the Navier-Stokes equations, is a viable alternative to theory; however, the computational resources required for simulations of complex flows have been a limiting factor. The increased availability of computational resources and the development of new algorithms has made it possible, in recent years, to approach more realistic problem. High-fidelity simulations have resulted in better understanding of the physics, and, in turn, in the development of more accurate lower-level models for industrial design.

In this talk the challenges associated with the simulation of turbulent flows will be discussed. The most common numerical methods will be presented, with their advantages and disadvantages. A series of illustrative examples from Piomelli's research group will then be presented.

(Short) Bio: Ugo Piomelli obtained a Laurea in Ingegneria Aeronautica from the Università di Napoli "Federico II" in 1979. He then earned a Master of Science Degree in Aerospace Engineering from the University of Notre Dame in 1984 and a PhD in Mechanical Engineering from Stanford University in 1988. From 1987 to 2008 he was on the faculty of the Department of Mechanical Engineering at the University of Maryland, first as Assistant, then Associate and finally Full Professor. He served as Associate Chair and Director of Graduate studies from 2002 to 2007. In August 2008 he joined the Department of Mechanical and Materials Engineering at Queen’s University in Kingston, Ontario, where he held, from 2008 to 2022, the Tier 1 Canada Research Chair in Turbulence Simulation and Modelling.

Professor Piomelli has published over 100 refereed journal articles in the fields of turbulence and transition modelling and simulation. His work has been cited over 24,400 times, and he has an h-index of 55 (Google Scholar). He was elected Fellow of the Royal Society of Canada in 2015, of the Canadian Academy of Engineering in 2021, of the American Society of Mechanical Engineers in 2009, of the Institute of Physics (UK) in 2004 and of the American Physical Society in 2002. Since 2015, he has been the Editor-in-Chief of the Journal of Turbulence. His present research includes studies of the flow in rivers and lakes, turbulent boundary layers over smooth and rough surfaces, model development for large-eddy simulations, and flows in hydro-electric turbines and aeronautical applications.