Weekly Seminar: Spring 2014
Speaker: Dr. Melissa Green (Syracuse University)
Title: "Eulerian and Lagrangian methods for coherent structure analysis of vortex-dominated flows"
Date: Friday, March 14, 2014
Time: 11:00 a.m.
Location: Gilman Hall 50 (Marjorie M. Fisher Hall)
There are a variety of tools and methods available to identify and investigate coherent structures in a range of vortex-dominated fluid flows, from both computational and experimental data. Eulerian criteria, such as the Q or swirl, use the instantaneous velocity field and its gradient and are less computationally intensive and give a good indication of the vortex cores. The definition of vortices, however, can be subjective, and they do not capture structure boundaries. Lagrangian techniques, such as the Finite-time Lyapunov exponent, calculate criteria values along particle trajectories, making them more computationally expensive, but they yield objective structure boundaries. For a thorough investigation of both numerically simulated and experimentally measured vortex-dominated flows, inclusion of both techniques can provide the most information. This is demonstrated with results from both simulation and experiments of a circular cylinder in cross-flow, and an experimentally investigated bio-inspired propulsor (fish-fin swimming).
Dr. Melissa A. Green received her B.S. in Aerospace Engineering from the University of Notre Dame in May 2003, and her Ph.D. from Princeton University in March 2009. As part of her Ph.D thesis research, Dr. Green experimentally studied the vortex wakes created by bio-inspired propulsors, and as part of a postdoc at Princeton University, Dr. Green studied the performance and fluid dynamics of manta ray swimming as part of an ONR MURI. Dr. Green was also awarded an NAS/NRC Postdoctoral Researcher Associateship to work with the Laboratories for Computational Physics and Fluid Dynamics at the Naval Research Laboratory in Washington, DC, where she worked on an analysis of turbulence-flame interaction simulations and low-order models for physiological circulatory flow systems. Dr. Green began her tenure-track position in the Syracuse University Department of Mechanical and Aerospace Engineering in January 2012.