On the role of motion element on the thrust contribution for fishlike swimming

The swimming performance is numerical simulated for three dimensional fishlike robot. To study the thrust contribution, this work considers the robot divided into seven motion elements along the fish axis from head to tail, executing the heave and pitch motion respectively. The results show that each motion element is found to yield thrust and the thrust takes on sinusoidal periodic variation. During a motion cycle, the value increases with the motion elements close to the tail, while a phase delay of thrust generation is found. Due to the thrust contribution by each motion element accompany with the phase difference existence, the total thrust may be adjusted to a reasonable value.