Passive wake detection using seal whisker-inspired sensing
Beem, Heather R.
MetadataShow full item record
This thesis is motivated by biological experiments, which display the harbor seal's ability to track the wake of an object several seconds after it swam by. In this work, I elucidate the basic fluid mechanisms that seals may employ to accomplish this detection. Key are the unique vortex-induced vibration (VIV) properties resulting from the geometry of the harbor seal whisker. First, force measurements and flow visualizations on a rigid whisker model undergoing 1-D imposed oscillations show that the geometry passively reduces VIV (factor of >10), despite contributions from effective added mass and damping. This suggests that harbor seal whiskers would detect details of the oncoming flow with reduced background “noise". Next, a biomimetic whisker sensor is designed by mounting the model on a four-armed flexure, allowing it to freely vibrate, and using strain gauges to measure deflections at the whisker base. Finally, this whisker device is towed behind an upstream cylinder with larger diameter. In the wake, the whisker oscillates with large amplitude and at the Strouhal frequency of the upstream cylinder. A slaloming motion among the wake vortices drives this interaction, and it enables detection of the upstream wake.
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 2015
Showing items related by title, author, creator and subject.
Cheney, Jerry (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1982-08)Zooplankton samples were collected with the MOCNESS (Multiple Opening/ Closing Net and Environmental Sensing System) on six cruises in the western North Atlantic Ocean during the period from August 1975 to November 1977 ...
Functional characterization and expression of molluscan detoxification enzymes and transporters involved in dietary allelochemical resistance Whalen, Kristen E. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2008-06)Understanding how organisms deal with potentially toxic or fitness-reducing allelochemicals is important for understanding patterns of predation and herbivory in the marine environment. The ability of marine consumers ...
Evolution of oceanic margins : rifting in the Gulf of California and sediment diapirism and mantle hydration during subduction Miller, Nathamiel C. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2013-06)This thesis investigates three processes that control the evolution of oceanic margins. Chapter 2 presents seismic images of a ~2-km-thick evaporite body in Guaymas Basin, central Gulf of California. In rifts, evaporites ...