Simulation Analysis of Variable Cross-section Linetype Optimization for Swim-out Tube in UUVs

In order to design the swim-out launcher unit for unmanned undersea vehicle(UUV), based on the thrust model and force model of swim-out launch process for electric torpedoes, the paper analyzes the thrust, fluid resistance, course resistance, and local resistance suffered by the torpedo during its swim-out launch process, establish a mathematical model for torpedo swim-out launch, and establish a simulation program to calculate the tube-exit velocity. Taking the launching speed as a key indicator, the linetype of variable cross-section swim-out tube is optimized. Determine the length and diameter of each section of the launch tube as constraints, and then build the mathematical expression of the optimization problem. To accelerate convergence, a genetic algorithm with adaptive mutation probability is used for optimizing the linetype of the tube, and 100 generations of simulation calculations are conducted. Compare the launching speed to obtain the optimization result. Based on the results, the optimal linetype of swim-out tubes is drawn. This result is a beneficial attempt to explore the variable cross-section launch technology of UUV and provides a theoretical basis for the design of the variable cross-section swim-out tube.