Stability analysis of flow structures in hovering using robotic experiments and flow visualizations

Abstract

We investigate the kinematics and stability of hovering flight making use of a robotic experimental device that simulate the movement of insects or birds. We carried out this analysis based on the characterization of this movement with flow visualizations and particle image velocimetry -PIV-. First, we characterized the kinematics of the robotic device inside water. Therefore, it has been verified that the robotic experiments follow the desired input signal precisely. Second, we give qualitative and quantitative information from the experimental tests as a function of frequency and angular amplitude. The kinematics of the hovering flight produces vortices that are stable or unstable around the rigid flat plate, as well as one transient regime that has been also found between these two latter states. Finally, dimensional velocity field plus associated vorticity have been characterized in these flow regimes through PIV measurements, and we also validated the reproducibility of experiment finding excellent agreement between different set of experiments.