GACLIT 75
Fall 2003
Morteza Gharib (PhD ’83)
Hans W. Liepmann Professor of Aeronautics and Bioengineering
Professor Gharib’s principal research interests are vortex flows, biofluid dynamics, wake flows, free-surface turbulence, bioengineering, and quantitative visualization.
If I see that the boxfish can do better control than a 747, I drop all this rigid stuff! One of the experiments we are doing aims at understanding how a boxfish stays next to a coral reef, the sharpest object you can imagine, in high turbulence, but keeps a distance of one millimeter. And doing it by having seven fins that are flapping and creating vortices here and there, keeping the fish right there, dead accurate. This problem is a combination of fluid mechanics, flexible compliant structures, and control. The future GALCIT will be tied to these new areas, and I think the next wave of smart propulsion devices will be based on the biomechanics of flying and swimming. But we need to learn how nature engineers these things.
Another area I am working in is free surface flow. My group is studying problems associated with the wakes of big ships. Last May we went on a ten-day field trip with a Naval research vessel.We have a Caltech camera under the boat to see what the propeller is doing. How is the propeller generating bubbles? How do the bubbles end up in the wake? The Navy spends $200 million per ship. These ships are radar-proof and stealth, but the wakes are not: you know exactly where they are.You don’t see the ship—you see the bubbles. That’s why we are helping them understand the mechanisms of wave breaking. Is it possible to remove an observable wake? It’s possible.
