Effect of Pectoral Fin Flapping Motion on Swimming Performance of Robotic Dolphin

Abstract

This paper proposes an elliptical trajectory pectoral fin flapping motion model, which can provide additional propulsion for robotic dolphins to obtain a better swimming performance. Firstly, a dolphin's body-pectoral-fin model is established. Then the force on the pectoral fin is evaluated through the blade element theory and a Computational Fluid Dynamics (CFD) method is employed to obtain the hydrodynamic performance of the robotic dolphin. Finally, the simulation results show the pressure and velocity distribution around the robotic dolphin. Moreover, important parameters such as propulsion and lift are also employed to validate the effectiveness of the flapping motion. The propulsion of the robotic dolphin increases with the pectoral fin flapping frequency, which depends on the relative fluid velocity of the pectoral fin. The results further illustrate an expected hydrodynamic performance of the elliptical trajectory pectoral fin motion model.