Meeting Abstract
Siphonophores and salps are colonial marine organisms comprising multiple swimming units that coordinate forward and reverse swimming. Recent work has focused on the role of coordination in achieving hydrodynamic efficiency and, in some cases, impressive vertical migrations by these multi-jet swimmers. Currently, we are investigating how individual kinematics by the nectophores (swimming bells) and jet wakes contribute to fast swimming, agility and maneuverability in the siphonophore Nanomia bijuga. High speed video of nectophore kinematics and PIV of the resultant jet wakes show the velar mechanics underlying agility and maneuverability. Rapid changes in the velar aperture area and shape produce high speed jets and high angular velocities during turning (agility). Fine-tuning of the velar angle during jetting achieves a low turning radius (maneuverability). The details of velum kinematics and associated fluid mechanics explain how siphonophores effectively navigate three-dimensional space and could be applied to exit flow parameters in multijet underwater vehicles.
