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Hairy little legs and noses: transitions in functions of appendages at low Reynolds number‚Äč

Special Events

Speaker: Mimi Koehl, UC Berkeley
Related Webpage: https://ib.berkeley.edu/labs/koehl/
Location: 1147 MSB
Start time: Fri, Oct 26 2018, 4:15PM

Many organisms use appendages bearing arrays of small hairs to capture food or molecules from the surrounding fluid, and to locomote or move fluid past themselves. The importance of inertia relative to viscosity in determining how these hairs interact with the surrounding fluid is given by Reynolds number (Re), which ranges between 10-5 to 1. Angela Cheer developed a model of the fluid flow around and through rows of hairs of finite width in this Re range and discovered that there are certain Reynolds numbers at which the flow between the hairs is particularly sensitive to changes in hair spacing, size, or speed. Inspired by that model, we have studied the hydrodynamics of how hair-bearing feeding appendages of small aquatic animals capture prey, and of how olfactory antennae capture odorant molecules. Cheer's work pointed the way for us to discover how the animals use transitions in the flow around and through their hair arrays to create currents, intercept prey, and sniff.

There will be a reception with light refreshments from 3:45-4:15 in the lobby of the Mathematical Sciences Building.