Swimming and Flying Somewhere Between the Microscale and Macroscale: Curious Adaptations in Parasito

Laura Miller Assistant ProfessorDept. of Mathematics U. North Carolina at Chapel Hill Chapel Hill, NC Biologists, engineers, physicists, and mathematicians have long studied the fluid dynamics of animal swimming and flying. In most cases, methods of locomotion are divided neatly into high Reynolds number mechanisms (flapping wings and fins, gliding, jet propulsion) and low Reynolds number mechanisms (cilia and flagella). For the most part, mechanisms of locomotion for Reynolds numbers between 0.1 and 10 have not been explored. In these flows, both inertial and viscous effects are significant, and a number of interesting biological adaptations appear. For example, the wings of the smallest insects have a bristled structure. Similar structures are also observed on the appendages of aquatic invertebrates such as copepods and beetles. Some fairyflies use bristled wings to fly in the air and also to swim in the water. In this presentation, the fluid dynamics of locomotion at these Reynolds number is explored. We use computational fluid dynamics and particle image velocimetry (PIV) to characterize the flow around simplified models of flapping wings and fins. The immersed boundary method is used to solve the Navier-Stokes equations around a moving, flexible wing or fin. We then describe thrust and lift generation in air and water over a range of Reynolds numbers and relate the magnitude of these forces to the behavior of the wake behind the flapping appendages. The role of bristled wings in locomotion is also examined. Finally, we describe similar problems in moving and pumping fluids over the same Reynolds number range.

Location: Robert Glen Rapp Engineering Research Building (RRB) - 208 Laufer Library

Audiences: Everyone Is Invited

Contact: April Mundy