Design of Rudder Mechanism to Maximize the Turning Force of a Ducted-Type Underwater Robot

The ducted-type underwater vehicle has a streamline outer shape and an inner duct. Fluid resistance is small due to streamline appearance, and because of the short length of the body, it has a small turning radius and good maneuverability. In this paper, the design of the rudder mechanism in which the rudder driving part is placed outside the duct is carried out and it is easy to increase the fluid acting area of the rudder compared to the rudder placed inside the duct. The degree of freedom of movement is also increased because it is free from interference and drive angle between rudders. The hydrodynamic analysis of the relationship between the state of the internal flow only and the optimum angle relationship between the driving angles of each rudder for maximizing the turning force was carried out.