Passively pulsed propulsion of aquatic vehicles

Recent work by Ruiz has shown that pulsed-jet propulsion for aquatic vehicles, similar to that used by sea jellies, salps, and squid, requires a significant decrease in energy input ($\sim$ 30\%). These results were obtained despite mechanical inefficiencies in the system to generate the pulsed flow. Thus an approach to generate the pulsed flow using a passive means has been explored. This approach uses collapsible tubing in a pressurized chamber to generate oscillatory, unsteady flow through the outlet. Current results will be presented along with a look toward future developments.