Development and Performance Analysis of Pneumatic Soft-Bodied Bionic Flipper

The sea lion fore flipper has superior underwater movement performance. Its structural characteristics and propulsion mechanism are drawn, combined with the large deformation and hyperelastic properties of silicone, a pneumatic soft-bodied bionic flipper with strong underwater mobility, good environmental adaptability, and flexible attitude transformation. Based on Yeoh's second-order constitutive model of silicone, the nonlinear dynamic analysis of the main limb of the bionic flipper is carried out, and the deformation analysis theoretical model is established. Then, the force analysis of infinitesimal and integral of the wing fin of the bionic flipper is analyzed by the blade element theory, to obtain the theoretical model of underwater propulsion dynamic performance. The superiority of the hydrodynamic performance of the bionic flipper is analyzed and confirmed using the bidirectional fluid-structure coupling numerical simulation algorithm. An experimental test platform is built to test the physical model of the bionic flipper. The motion and dynamic characteristics curves of the bionic flipper are obtained and compared with the corresponding numerical simulation results. The results show that the theoretical model and numerical simulation are accurate, and the structure is feasible, which can provide methods and references for the research and implementation of the underwater propeller.