Events Calendar

AME - Department Seminar

Speaker: John K. Eaton, Charles Lee Powell Foundation Professor of Engineering in the Mechanical Engineering Department at Stanford University

Talk Title: Magnetic Resonance Imaging for Measurement of Velocity and Concentration in Complex Turbulent Flows

Abstract: Magnetic Resonance Imaging (MRI) based flow measurement techniques are enabling a paradigm shift in how we study, evaluate, and design turbulent flows in complex geometries. MR Velocimetry (MRV) measures a complete 3-D mean velocity field and does not require flow tracers or optical access. Resolutions as fine as 0.25 mm have been achieved in measurement volumes as large as 100 X 100 X 250 mm. An entire velocity field comprising millions of individual data points can be measured in a few hours. When combined with computer-aided design and rapid-prototyping of the flow model, a complete mapping of a flowfield from conception to data analysis can be completed in a week. This versatile technique has been used to map the external flow around a coral colony, internal flows in serpentine passages, separated flows in three dimensional diffusers, and the combination of flows found in a full combustor geometry. The detailed 3D measurements allow understanding of vortex structures which dominate many flows, the interplay between separation zones, and analysis of flow splits among parallel paths. A second technique called Magnetic Resonance Concentration (MRC) provides quantitative measurements of the time-averaged 3D concentration field for passive scalar mixing. The combination of measured 3D concentration and velocity fields provides enough detail to yield exceptional understanding of the effects of mean flow transport and turbulent mixing. This has proved particularly effective in the iterative design of film-cooling and other systems where we wish to suppress turbulent mixing. In addition, the combined velocity and concentration data are being used to characterize and improve numerical models for turbulent mixing.

Biography: John K. Eaton is the Charles Lee Powell Foundation Professor of Engineering at Stanford University where he has been on the faculty since 1980. He earned all his degrees at in Mechanical Engineering at Stanford. He conducts research in turbulence, convective heat transfer, advanced measurement techniques, multiphase flow, and flow through random media. Recent emphasis has been on high-fidelity, rapid turnaround experiments in complex flows, measurement and modeling of turbulent mixing, and extreme sensitivity of certain high Reynolds number flows to small perturbations. Much of Professor Eaton's work is motivated and funded by problems in the gas turbine industry. He has supervised 49 completed Ph.D. dissertations including those of 15 professors. He has won both the Tau Beta Pi and Perin Awards for teaching excellence, was an NSF Presidential Young Investigator Awardee, and is a Fellow of the American Society of Mechanical Engineers and the American Physical Society.

Host: Professor Maxworthy

More Info: http://ae-www.usc.edu/seminars/10-17-12-eaton.shtml

Location: Seaver Science Library (SSL) - Room 150

Audiences: Everyone Is Invited

Contact: April Mundy

Event Link: http://ae-www.usc.edu/seminars/10-17-12-eaton.shtml