Free Flight Simulations of Inertial Effects in Insect Flight

We investigate the role of inertial effects in insect flight. Previous work has examined how the hinge position of the wing and flight kinematic parameters optimize flight. Here, we use a free flight model (PNAS 2014, JFM 2018) to investigate the effect of body and wing inertia on dynamics and stability. We report two sets of simulation results. The first set varies the insect mass and pitching moment of inertia independently. The second set varies the wing to body mass ratio (WBMR) while constraining total insect mass to be constant. To understand the simulation results, we apply a simplified 2 point mass model (JFM 2018). This model explains observed minima in the pitching of the insect as we vary the WBMR due to the canceling of aerodynamic and inertial torque terms, and can be closely related to previous results which varied wing hinge position (JFM 2018). We further discuss simulation results that cannot be explained by the simple model, such as a maximum instability when varying the pitching moment of inertia.

S. Chang and Z. J. Wang, Proc. Natl. Acad. Sci. U.S.A. 111, 11246–11251 (2014).

R.M. Noest and Z. J. Wang, Journal of Fluid Mechanics 849, 498 (2018).