Design and Operation Optimization of the Flapping Fin for AUV Propulsion

Abstract

It has been proved that flapping fins can generate thrust from both theoretical and experimental prospects, but the structural optimization of a flapping fin is not well studied so far, especially the ones applied on the autonomous underwater vehicles (AUV). In this study, the propulsion effect of the flapping fin is numerically investigated with different fin shapes and different operating conditions to optimize its thrust performance. The NACA 0012 foil is adopted to establish the simulation model with computational fluid dynamics (CFD) approaches. Uncertainty study and validation test are conducted to guarantee the simulation quality as well as the accuracy of the results from Star CCM+. The simulation results show that different fin shapes and operation conditions would impact the thrust performance notably. These mentioned factors would significantly affect the magnitude and distribution of the pressure around the flapping fin, and then affect the propulsion force generated by the flapping fin. It is observed that the trapezoid shape flapping fin and a higher wave height and frequency could significantly enhance the propulsion force.