Zhang, JunJunZhangBai, YaqiangYaqiangBaiZhai, ShuchengShuchengZhaiGao, DebaoDebaoGaoSu, BoyueBoyueSu2021-03-172021-03-172019-0911th International Workshop on Ship and Marine Hydrodynamics (IWSH2019), Paper 86http://hdl.handle.net/11420/9048The fishes swim with high efficiency and low noise, gives us important enlightenment on propulsor design. The Gymnarchus Niloticus Fish (GNF) swimming by a long undulating dorsal-fin generally cruises with high efficiency and extra-ordinal manoeuvrability while keeping its body for the straight line. In the paper the hydrodynamics and vortexes structure of undulating fins in stationary water are calculated by Large Eddy Simulation(LES) and dynamic grid technique with diffusion-based smoothing model. The thrust produced by undulating fins is measured at wave amplitude of 850, and the unsteady flow field around undulating fins on the middle cross section and mid-sagittal plane at wave amplitude of 850 is measured by phase-locked Particle Image Velocimetry(PIV) in the stationary water. The thrust calculated by numerical simulation is in good agreement with hydrodynamics experiments. The vortex structure and its evolution on cross sections and mid-sagittal plane calculated by LES qualitatively agree well with PIV experiments. The vortexes structure and mechanism of hydrodynamics generation are analyzed.enhttp://rightsstatements.org/vocab/InC/1.0/Bionic propulsionUndulating finsVortex structuresIngenieurwissenschaftenConference Paper10.15480/882.337310.15480/882.3373Fluiddynamik und Schiffstheorie M-8Other