Numerical simulation of exploring fish motion by a series of linked rigid bodies

Propulsion and manoeuvring ability are parts of the most common and complicated mechanisms in nature, such as fish swimming in the water and birds flying in the sky. In order to get a deep understanding of these problems, a comprehensive and completed replication of fish movements is carried out in this project. Present work is based on a robotic fish named Amphibot III, which is a bio-inspired swimming robot. It is composed of 8 elements and the last part has a caudal fin attached as a tail. By using CFD method, the caudal fin is omitted in order to simplify the model. These elements in the model are connected by hinges. Commercial software FLUENT is used to solve flow field. Swimming tests are performed under two different conditions by varying the frequency and amplitude of the angular motion at the hinges. The motion curve at the head of fish is presented under both conditions.