Influence of Muscle Flexibility on Propulsion Performance of Soft Flapping

Marine organisms represented by manta rays flap the water flow through flexible flapping wing and use passive deformation of the wing surface to obtain propulsion force, thus having high propulsion efficiency. To better study the effect of muscle flexibility on the hydrodynamic performance of the bionic flapping wing, in this paper, we use double-fin strip building models. The overall flexibility distribution of the bionic muscle is changed by changing the distance between the two fin rays. We define the ratio of the distance between the two fin rays to the overall chord length of the model as the dimensionless fin ray spacing q, and study the changes of thrust, lift, pitch moment and push-up ratio with q through a series of hydrodynamic experiments. Experimental results show that biomimetic flapping wings can produce periodic changes in thrust and lift, and the change trend is closely related to the change of dimensionless fin ray spacing q.