Jean Hertzberg

Artist and Associate Professor of Mechanical Engineering
Dept. Mech. Enging, University of Colorado Boulder
Boulder, Colorado, USA

I am passionate about flow visualization, the process of making the physics of fluid flows (gases, liquids) visible. I am motivated not just by the utility and importance of fluid flows, but also by their inherent beauty, whether imaged directly by photography or by more abstract measurements and data visualization. Flow visualization embodies both art and science, which are similar in that they both thrive on deep seeing, on expanded perception and attention, which can be gained through simple experience.Everyone is capable of experiencing flow visualization. Spend some time noticing fluid flows around you and you’ll find your life is richer.

Flow of the Heart
18 x 28 cm
Metal photo print

What happens in the human heart? At a prosaic level, we can measure the velocity of the blood with 4DMRI technology. The velocity field in the right ventricle of a normal subject is shown as white velocity vectors; the larger the white pencil shapes, the faster the flow at that location. Vorticity, computed as the curl of the velocity field, is represented by the colored arrows; the arrow shaft is the local axis of spin at that location. We see flow penetrating deep into ventricle, during diastole, as the ventricle fills, preparing to pump blood to the lungs. Vorticity surrounds the flow, generated by shear at the walls of the tricuspid leaflets and other structures in the ventricle. Vortex rings are formed and washed away with each beat.