Events Calendar

Aerospace and Mechanical Engineering Seminar Series

Speaker: Joe Klewicki, Professor in Department of Mechanical Engineering University of New Hampshire, Durham, NH & University of Melbourne, Parkville, VIC, Australia

Talk Title: Self-Similarity in the Inertial Region of Wall Turbulence

Series: Aerospace and Mechanical Engineering Seminar Series

Abstract: The inverse of the von Karman constant, K, is the leading coefficient in the equation describing the logarithmic mean velocity profile in wall bounded turbulent flows. Previous research demonstrates that the asymptomatic value of K derives from an emerging condition of dynamic self-similar hierarchy of scaling layers. First-principles based analyses are used to reveal a number of properties associated with the asymptomatic value of K. The development leads toward, but terminates short of, analytically determining a value for K. Consistent with the differential transformations underlying the invariant form admitted by the governing mean equation, it is further demonstrated that the value of K arises from two geometric features associated with the inertial turbulent motions responsible for momentum transport. One nominally pertains to the shape of the relevant motions as quantified by their area coverage in any given wall-parallel plane, and the other pertains to the changing size of these motions in the wall-nominal direction. Data from direct numerical simulations and higher Reynolds number experiments convincingly support the self-similar geometric structure indicated by the analysis.

Biography: Joseph Klewicki holds joint appointments in the Departments of Mechanical Engineering at the University of Melbourne, Australia and the University of New Hampshire. He is a Fellow of the American Society of Mechanical Engineers (ASME) and a Distinguished Alumnus of the Michigan State University (MSU) Department of Mechanical Engineering. He received his BS (1983), MS (1985) and PhD (1989) degrees from MSU, Georgia Tech and MSU respectively. His areas of specialization include experimental methods in fluid mechanics, turbulent and unsteady flows, vorticity dynamics, boundary layers, atmosphere surface layer phenomena.

Host: Professor Paul Ronney

Location: Seaver Science Library (SSL) - 150

Audiences: Everyone Is Invited

Contact: Valerie Childress