Thrust characteristic of a caudal fin with spanwise variable phase

• This paper proposes an analysis method to calculate the thrust of fish fin.
• To simplify the analysis on the fin, the energy method was proposed.
• A flat fin and a waving fin were analyzed and compared using the method.
• Real experiments have been conducted to validate the developed method.
• From the experiments, we could validate the experimental results.

In this paper, the thrust characteristics of a robotic fish with spanwise variable phase are discussed. To analyze the thrust performance of a robotic fish with spanwise variable phase, an analytical method that uses a simplified method and energy equations is proposed. Experiments were also performed to validate the developed method. The analytical results demonstrate that the thrust characteristic of a caudal fin with spanwise variable phase differs from that of a conventional plate-type caudal fin.