Hydrodynamic performance and calculation of lift–drag ratio on underwater glider

The hydrodynamic performance and lift-drag ratio of the underwater glider affected the state of its own operation. Therefore, a three-dimensional physical model and a mathematical model of a certain type of underwater glider are established. According to the principles of aircraft performance characterization, the fluid dynamics method was used to simulate the pressure distribution of the underwater glider pressure field and the overall outflow field, under the attack angle from − 10° to 10° and the gliding speeds were 0.25 m/s, 0.5 m/s, 0.75 m/s, and 1 m/s. Finally, the drag experiment of this type of underwater glider is verified. It is concluded that as the gliding speed increases, the pressure of the high-pressure area of is increases, the pressure of the low-pressure area decreases, and the pressure difference resistance increases continuously. In the case of small attack angle (  8°), the lift–drag ratio tends to decrease slightly with increase in attack angle. The maximum lift–drag ratio is produced at an attack angle about 8° and the underwater glider can get maximum hydrodynamic efficiency at this attack angle.