Direct Numerical Simulations of the Aerodynamics of Insect Inspired Gliders

While insects have often served as bioinspiration for flapping wing micro-aerial vehicles, several large insects such as grasshoppers, butterflies, moths, and dragonflies also exhibit excellent capabilities for gliding. We employ direct numerical simulations using an in-house ghost cell immersed boundary method-based CFD code to investigate the aerodynamics of a grasshopper-inspired glider. The glider is modeled as a thin membrane structure, and we examine the glider's performance in the context of various aerodynamic parameters such as Reynolds number, angle-of-attack, and roll angle and their impacts on the aerodynamics as well as quantities such as drag and lift coefficients. The effect of the presence of wing corrugations is also studied in this framework, along with the contribution of different flow structures such as wake and wing tip vortices using the Force and Moment Partitioning Method (FMPM). A special emphasis is placed on understanding the roll and pitch moment characteristics that ultimately affect the glider's stability.