McGowan Library Auditorium
UGA Skidaway Institute of Oceanography

Joseph Kuehl, Ph.D.
Assistant Professor
University of Delaware

Description:

The existence of multiple steady flow states in nonlinear fluid dynamic systems has been observed in many situations. Probably the most well known classical fluid dynamic example is the Coanda (Teapot) Effect, in which a slowly tilted teapot will spill. In oceanography, the discussion of multiple steady states is generally concerned with the density driven (thermohaline) overturning circulation which connects the upper and lower ocean and its climatological implications. However, in this work multiple steady states are identified as the result of a different fundamental balance than the two examples given above. In the context of a gap leaping boundary current (loop current) it is shown that the competition between inertia and vorticity constraints can lead to multiple steady states (gap leaping or gap penetrating). Barotropic and baroclinic rotating table experiments will be presented and various properties of the system will be explored.

Dr. Kuehl holds Ph.D.s in mechanical engineering and physical oceanography from the University of Rhode Island and Graduate School of Oceanography (2009). His research interests include hypersonic boundary-layer stability (numerical laminar-turbulent transition), nonlinear vibrations (time series analysis, modal decomposition techniques and finite time invariant manifold analysis) and geophysical fluid dynamics (gap-leaping boundary currents, geophysical boundary layer dynamics and transport phenomena). He was the recipient of the AFOSR Young Investigator Award (2015) for his hypersonic boundary layer stability and transition research, participates in the NATO STO AVT-240 hypersonic vehicle working group and has been selected for the National Academy of Science Committee on Advancing Understanding of the Gulf of Mexico Loop Current Dynamics.