Koehl, M. University of California at Berkeley, cnidaria@socrates.berkeley.edu
Cooper, T. University of California at Berkeley, tjcooper@socrates.berkeley.edu
McCay, M. University of California at Berkeley, mccay@socrates.berkeley.edu
Wang, G. University of California at Berkeley, g_wang@uclink4

 
SMALL-SCALE HYDRODYNAMICS OF COPEPOD FEEDING APPENDAGES: HOW DO FLAPPING HAIRY LEGS PRODUCE NET FLOW AT LOW AND TRANSITIONAL REYNOLDS NUMBERS?
 
Many marine animals use hair-bearing appendages to locomote or create ventilatory currents, or to capture food particles or molecules from the surrounding water. These appendages operate at a range of Reynolds numbers for which viscosity is more important than inertia in determining the fluid motion. How can appendages that flap back and forth produce a net water current in this realm where viscous damping is more important than intertial gliding? We have used dynamically-scaled physical models (on which we can vary one parameter at a time to quantify its effects on the flow field produced) to sort out which aspects of the morphology and motion of hairy appendages contribute to their ability to produce net fluid motion in these viscous flow regimes. The examples of the particle-capturing second maxillae from various species of copepods illustrate several mechanisms by which altering the leakiness of the meshwork of hairs on an appendage at different times in the cycle of flapping can produce net water flow and lead to particle capture or rejection.
 
Day: Tuesday, Feb. 2
Time: 04:30 - 04:45pm
Location: Hilton of Santa Fe
 
Code: SS02TU1505S