Interior Trajectory Characteristics of Ram Piston Device in UUV for Torpedo Launching

Abstract

For lightweight and small volume requirements of unmanned undersea vehicles (UUVs), a hydraulic cylinder-ram piston-grid tube launch device was presented in this paper. To evaluate the dynamic characteristics of the device, the dynamic model of the device for torpedo launching was established based on the theory of fluid dynamics and interior trajectory. The pressure characteristics of the front and rear ends of the ram piston and the interior trajectory characteristics of the device for torpedo launching were obtained with the hydraulic cylinder velocity as input. Through comparison, it is verified that the calculation results of the above model are in good agreement with the simulation results of fluid dynamics, which indicates the reliability of the established model. The results show that the maximum resistance generated during the movement of the ram piston is 0.43 MPa. In order to satisfy the velocity input of the hydraulic cylinder, the output pressure and power of the hydraulic cylinder are designed based on the above results. When the ram piston moves 0.42 s and then decelerates, the torpedo moves about 3.9 m. In order to reduce the pressure differential resistance of the torpedo in subsequent movement, the hole location of the grid tube can be optimized according to the above results to enhance the replenishing capacity and improve the performance of the launcher.

Keywords

• unmanned undersea vehicle
• torpedo
• hydraulic cylinder-ram piston-grid tube
• fluid dynamics
• interior trajectory
• replenishing capacity