CAREER: Fluid-structure interactions and vortex dynamics of multi-jet propulsion inspired by colonial swimmers

Some of the ocean’s most efficient swimmers, including jellyfish, salps, and siphonophores, move by expelling water in the form of vortex rings. These vortex rings are created by the systematic contraction and relaxation of their bodies. Colonial siphonophores have many small, flexible, jetting units along their body. These units can coordinate to produce multiple pulsed vortex rings at once, enabling efficient swimming and dynamic and complex directional control. Inspired by these systems, this project will explore how body flexibility and the coordination of multiple vortex rings lead to improvements in swimming efficiency and maneuverability. Findings from this research will inform new design principles for next-generation bio-inspired underwater vehicles, and support advances in ocean exploration, environmental monitoring, and underwater soft robotics. The project will also provide opportunities for students to develop skills in engineering communication and support science education through teacher partnerships and classroom-ready learning materials. This project supports improved advanced manufacturing of robotic swimming vehicles. The goal of this research is to understand how fluid-flexible structure interactions and vortex-vortex interactions influence vortex formation, thrust, and maneuverability in multi-jet systems. This will be achieved by a comprehensive laboratory approach using simultaneous flow and material deformation measurements. Full-cycle analysis of vortex rings generated by flexible materials will reveal how flow and material timescales govern vortex strength and propulsive performance. Three-dimensional constructive and destructive interactions between neighboring vortex rings in multi-jet systems will be assessed to identify flow and geometric configurations that maximize efficiency and control. Understanding these mechanisms will lay the foundations for designing efficient, controllable multi-jet propulsion systems, and expand scientific knowledge of fluid–structure interactions in biologically inspired systems. This project will also be synergistically connected to educational activities that include: (i) establishing a multi-disciplinary module for undergraduate and graduate classrooms using flow visualization as a means of scientific communication; (ii) enhancing Montana K-12 education via teacher research experiences; and (iii) developing classroom-ready fluid dynamics education kits and outreach activities for K-12 classrooms. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.