Meeting Abstract
Moon jellyfish (Aurelia aurita) and upside-down jellyfish (Cassiopea) both mix surrounding fluid through contraction and expansion of their bells, the former for locomotion and feeding and the latter primarily as a method of nutrient exchange. The relatively simple shapes of jellyfish bells and their high swimming efficiency has led to interest in understanding the fluid dynamics and mechanical bell design for applications in mathematical modeling and the design of bioinspired underwater vehicles. We use particle image velocimetry (PIV) and dye visualization to reveal the vortex wake produced by both species in forward swimming, turning, and feeding. PIV is a method of flow visualization where a high-powered laser sheet illuminates seeding particles in the fluid and a cross-correlation algorithm is used to determine the velocity flow field from the particles’ displacement. The translucence of moon jellyfish led to relatively successful creation of vector fields showing the train of vortex rings shed in their wake. Dye provided an excellent tool for visualizing the upward jet produced by stationary pulsing of upside-down jellyfish.
