Comparison of Spherical and Fish-shaped Robots on Hydrodynamic and Pressure Characteristics in Static Water

During the underwater movement of underwater robot, a large part of interference comes from the interaction between robot and water flow. In order to control the underwater robot accurately, it is very important to study the hydrodynamic characteristics of the robot. In this paper, the hydrodynamic characteristics about two kinds of underwater robots (spherical and fish-shaped robot) are studied according the application. Firstly, the hydrodynamic characteristics of the two shapes are studied by the qualitative analysis of velocity field and pressure field. Then, by changing the speed and volume of the robot, the drag resistance force of the robot is further quantitatively analyzed. These obtained characteristics can be used to guide the application of flow rate sensing and pressure sensing on underwater robots.