NUMERICAL STUDY ON MANEUVERING MOTION OF A BIONIC ROBOTIC FISH WITH TWIN-FIN BASED ON SELF-PROPELLED SWIMMING

As a typical fish with medal/paired fin (MPF) undulating propulsion mode, batoids rely on the flexible movement of pectoral fins on both sides of the body for maneuvering and free control of motion posture. It is of great theoretical significance to study the propulsion mechanism of batoids and apply it to the development of bionic underwater vehicles. Based on the morphology and motion characteristics of batoids, a bionic robotic fish with two undulating pectoral fins was established in this paper. Then, based on computational fluid dynamics (CFD) method, a numerical scheme for the maneuvering motion of the bionic robotic fish was established. The motion characteristics, hydrodynamic performance and pressure contour of the bionic robotic fish under different motion parameters were studied. The results show that under different forward speeds, changing the wave direction of the fins can realize the fast and steady turning of the robot fish, and controlling the initial forward speed of the robot fish can realize the maneuvering motion during the forward swimming. The results of numerical calculation show that the MPF undulating propulsion mode has significant advantages in propulsion with high stability and maneuvering motion.