TY - EJOU AU - Xu, Na AU - Zhou, Shuaizhi AU - Zhang, Chunchen AU - Mou, Xiaolei TI - A Computational Study on Lateral Flight Stability of the Cranefly in Hover T2 - Computer Modeling in Engineering \& Sciences PY - 2021 VL - 128 IS - 2 SN - 1526-1506 AB - The dynamic flight stability of hovering insects includes the longitudinal and lateral motion. Research results have shown that for the majority of hovering insects the same longitudinal natural modes are identified and the hovering flight in longitudinal is unstable. However, in lateral, the modal structure for hovering insects could be different and the stability property of lateral disturbance motion is not as robust as that of longitudinal motion. The cranefly possesses larger aspect ratio and lower Reynolds number, and such differences in morphology and kinematics may make the lateral dynamic stability different. In this paper, the lateral flight stability of the cranefly in hover is investigated by numerical simulation. Firstly, the stability derivatives are acquired by solving the incompressible Navier–Stokes equations. Subsequently, the dynamic stability characteristics are checked by analyzing the eigenvalues and eigenvectors of the linearized system. Computational results indicate that the lateral dynamic modal structure of cranefly is different from most other insects, consisting of three natural modes, and the weakly oscillatory mode illustrates the hovering lateral flight is nearly neutral. This neutral stability is mainly caused by the negative derivative of roll-moment vs. sideslip-velocity, which can be attributed to the weaker ‘changing-LEV-axial-velocity’ effect. These results suggest that insects in nature may exhibit different dynamic stabilities with different morphological and kinematic parameters, which should be considered in the designs of flapping wing air vehicles. KW - Flapping flight; cranefly; lateral flight stability; natural modes of motion; computational fluid dynamics DO - 10.32604/cmes.2021.016269