Thrust magnitude and efficiency studies for multiple robotic flapping fins

The development of multiple generations of robotic flapping pectoral fins has warranted a closer study of the relative thrusts and efficiencies exhibited by these fins. This paper describes the differences between the various fins - including stroke frequency, stroke amplitude, aspect ratio, and effective angle of attack - and investigates the effects these differences have on thrust generation and propulsive efficiency. Drawing from and building on previous fin results, both computational fluid dynamics (CFD) simulation results and experimental data are used to evaluate the thrust, power draw, and efficiency, and to find useful relationships between these values and parameters such as Strouhal number and advance ratio. This analysis has implication for future fin design and development of reduced order models for flapping propulsion mechanisms.