Fluid Mechanics

Background

During my Ph.D. I designed and built experiments to study the physics of turbulent flow in systems that spin rapidly. The rapid rotation shapes the flow in interesting ways.

Stroboscopic time lapse (left) and real-time (right) of dye injected into oscillating flow.

Familiar visible examples are the bands and spots of Jupiter, the organized swirling of terrestrial hurricanes and typhoons, and the wavy form of the jet streams. Rotation also shapes the flows in the deep ocean and in the cores of planets and stars in a way that's less visible but just as important.

The University of Maryland 3m Geodynamo Experiment is one of the most strongly rotating laboratory experiments ever built in the sense of the dominance of the Coriolis force. It's also so large that the slow rotation of the Earth drives a flow in the rapidly spinning experiment similar to the way that Earth's 26,000 year precession probably drives a flow in Earth's rotating core.

The videos on this page show the flow caused by this precession-driven flow, as the fluid oscillates in the rotating frame to resolve the fact that it's rotating around two non-parallel axes at once. The oscillations in the right video are the real-time flow showing the oscillating columnar structures typical in rotating turbulence. The video on the left condenses 47 minutes of flow observations and condenses it to one frame per oscillation period, showing how the dye slowly mixes around the columnar structures.

My focus in recent years has moved away from fundamental research on geophysical and astrophysical fluid phenomena toward fluid-structure-interaction and solid mechanics research applied to robotics and hydrokinetic energy harvesting.