Abstract: The shark fin, the pectoral fin and the dorsal fin were studied based on the numerical simulation method; the pressure field, velocity field and flow field of the specimen structure were analyzed with three different flow velocities; the analysis and comparison of the mechanical properties of caudal fin, dorsal fin and pectoral fin were presented. The results show that the setting width of the tail fin can be set to 0.5 ~ 4.8 meters so as to improve the anti-karman vortex effect; the width of the tail fins should be relatively narrow in order to guarantee the base of 0.5 ~ 4.8 meters when the main working direction of the bionic machine equipment is in the same direction as the current direction; the width of the tail fins should be relatively wide for the main direction of work in the same plane; the force of the pectoral fins is about twice as much as the dorsal fin in the same velocity field, and the better the structural streamline, the lower the resistance.

Key words: numerical simulation, shark fin, mechanical performance, biomimetic mechanical, turbine