Three-dimensional simulation of a self-propelled fish-like body swimming in a channel

In this study, a three-dimensional simulation of a fish-like body swimming in a channel with non-slip walls was carried out to investigate the effects of kinematics on swimming performance. Self-propelled swimming in an inertial coordinate system was examined by using the direct forcing immersed boundary method. The fish body consisted of several rigid bodies and behaved analogously to a multi-segment robotic fish. The computational program was first validated by simulating fluid flow around a circular cylinder at Reynolds number (Re) =100 and Re = 1000, as well as around a settling particle. The results were compared with experimental and numerical results from past research in the area. A virtual parametric study of the tail-beat frequency, phase difference between neighboring body segments, and body amplitude was then conducted. The effect of the lateral and vertical distance between the model body and walls on swimming performance is also discussed. The results for the velocity and vorticity fields around the model body provided evidence for the mechanism of thrust generation and highlighted the effects of kinematics on swimming performance.