Reduced Order Modeling of Wake Structures in Hawkmoth Hovering Flight

As insects fly, their wings generate complex wake structures that play a crucial role in their aerodynamic force production. This study focuses on utilizing reduced order modeling techniques to gain valuable insights into the fluid dynamic principles underlying insect flight. Specifically, we used an immersed-boundary-method-based computational fluid dynamics (CFD) solver to simulate a hovering hawkmoth's wake, and then identified the most energetic modes of the wake using proper orthogonal decomposition (POD). Furthermore, we employed a sparse identification of nonlinear dynamics (SINDy) approach to find a reduced order model that correlates these energetic POD modes. Based on the wake predicted by the SINDy models, we estimated the lift generated by the hawkmoth's wings using a force survey method. By comparing the estimated aerodynamic force with the force production calculated by the CFD solver, we can evaluate the accuracy of various SINDy models. The reduced order modeling of insect flight has important implications for the design and control of bio-inspired micro-aerial vehicles. In addition, it holds the potential to reduce the computational cost associated with high-fidelity CFD simulations of complex flows.