Woodruff School of Mechanical Engineering

Faculty Candidate Seminar

Title:

Visualization study of quantum fluid dynamics in superfluid Helium

Speaker:

Dr. Wei Guo

Affiliation:

Florida State University

When:

Monday, February 11, 2019 at 11:00:00 AM

Where:

MRDC Building, Room 4211

Host:

Dr, Satish Kumar
satish.kumar@me.gatech.edu
4046701591

Abstract

Helium-4 in the superfluid phase (He II) is a two-fluid system that exhibits fascinating quantum fluid dynamics with important scientific and engineering applications. It supports the most efficient heat-transfer mechanism (i.e., thermal counterflow), and it also allows the generation of quasiclassical flows with extremely high Reynolds numbers for turbulence modelling. However, the lack of high-precision flow measurement tools in He II has impeded the progress in understanding and utilizing its hydrodynamics. In recent years, there have been extensive efforts in developing quantitative flow visualization techniques applicable to He II [1]. Two types of techniques based on the use of either particle tracers (i.e. micron-sized frozen particles) or molecular tracers (i.e. helium excimer molecules) have been developed. I will discuss the advantages and issues associated with these visualization techniques and will highlight some recent progresses in our visualization study of thermal counterflow and quasiclasscial turbulence in He II [2-4]. I will also briefly introduce our on-going work on developing the next generation flow visualization techniques and our effort on imaging quantized vortices in a magnetically levitated He II drop.


Biography

Bio: Dr. Wei Guo is an Associate Professor of the Mechanical Engineering Department at Florida State University. He also holds an associate position at the National High Magnetic Field Laboratory. Dr. Guo received his Ph.D in physics from Brown University in 2008. After graduation, he worked at Yale University as a postdoc in 2008-2010 and as a research scientist in 2010-2012. He joined Florida State University in the summer of 2012. His research interests include quantum fluid dynamics, cryogenic heat and mass transfer, cavitation and bubble dynamics, and cryogenic particle detector and accelerator R&D. His work has been supported by federal agencies, such as the National Science Foundation, US Department of Energy, NASA, Army Research Office, as well as national labs and industrial partners.

Notes

Refreshments will be served.