EAGER/Collaborative Research: Revealing the Physical Mechanisms Underlying the Extraordinary Stability of Flying Insects

This EArly-concept Grant for Exploratory Research (EAGER) investigates how certain insects may tolerate large disturbances during flight, without tumbling out of control. High-speed images of a free-flying hawkmoth showed the insect -- after being impulsively accelerated to a spin rate of 5,000 degrees per second -- returning to normal flight in only a few wing beats. Computer simulations suggest that this rapid recovery may be due to a spring-like force from the air displaced by the sudden motion of the moth’s body. These forces were not previously thought to be important in hawkmoth flight. This project will use mathematical analyses and high-fidelity computer simulations to fully explore and explain this surprising result. The knowledge gained from this work will help safeguard future aircraft; the observed behavior is beyond the capability of current flight control technology. Preliminary analysis suggests that the body-added mass effect plays a central role in the observed ability of the hawkmoth to recover from impulsive acceleration to high pitch rates. This study will apply a combination of theoretical and computational methods to understand the interplay between body flight dynamics and unsteady flow, at timescales significantly faster than the wing beat period. Specific tasks include (i) dynamic analysis of body added mass effects and comparison to existing insect flight disturbance response data; (ii) high-fidelity computational fluid dynamic simulations of added mass effects, and (iii) analysis of added mass effects in the presence of vortical flow. The study will include development of approaches to implement the newly understood high-rate recovery mechanisms on future unpiloted aerial vehicles. 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.