The focus of the proposed project is to explore the fluid dynamic principles that enable small insects to generate lift and produce thrust. When the wings of small insects clap together during the flapping motion and then fling apart, there is the expectation that flight would not be efficient, but it is. Resolving this paradox can have a significant scientific and technological impact, because we could also design machinery that takes advantage of such phenomena like small robotic vehicles that move across fluid-air interfaces.
The proposal is focused on the understanding of the phenomena involved when bristled wings, like those of small insects generate lift. Although the aerodynamic principles of insect flight at the scale of fruit flies and above are reasonably well understood, the fluid dynamic mechanisms that enable very tiny insects to generate lift or thrust remain unclear. When the wings clap together at the end of the upstroke of the flapping motion and fling apart at the start of the downstroke, there are novel phenomena that take place. The fundamental investigation in this work will be focused on a particularly intriguing paradox: why is there a noted biological preference in almost all tiny insects to employ interacting bristled wings under highly viscous conditions that would require large forces to peel the wings apart? It is proposed to develop 3D poroelastic models to study locomotion using bristled appendages. Two types of insects will be examined (thrips and parasitoid wasps), which are capable of flying in air and swimming in water. The experiments in this proposal will also use robotic wing-wing interaction platforms with dynamically scaled bristled wing models informed by high-speed videos of tiny insects. Wing design and kinematics for flapping propulsion at low Re will be identified through numerical simulations of experimentally validated poroelastic wing models implemented in an immersed boundary method framework. Graduate and undergraduate student involvement in the research is proposed. Minority student participation will be pursued through the Louis Stokes Alliances for Minority Participation (LSAMP) program at both institutions. Outreach activities for high school students and teachers participating in the Oklahoma State University National Lab Day annual event are also described.
