The Main Shape Of The Underwater Craft Low-impedance Low-noise Integrated Optimization Design

The excellent hydrodynamic form is crucial for the tactical performance of an underwater vehicle. The minimum drag coefficient and the lowest self-noise is the required principally desiging the underwater vehicle main form. In the thesis the low drag-low noise optimization of the vehicle main form design is realized, main accomplishments are as follows.Researched the knowledge of drag and flow noise, the parameters of the boundary layer are calculated by the Hess-Smith method and Boundary layer Momentum Integral method. The calculation of the length of transition zone and change in boundary layer displacement thickness between laminar and turbulent states in the transition is improved, then the drag coefficient and self-noise from the transition zone are calculated as the objective functions of the optimization.According to the characters of the model of the optimization of the vehicle main form design, The muti-objective problem is resolved by power-factor method, the constrains problem by penalty function technique. Lastly the genetic algorithm charactered with real-coding, anneal-simulation penalty-function is designed.Eventually the low-drag low-noise optimization of the vehicle main form design is realized. The optimization results and analyse are provided, the results calculated theoretically and the results from the wind tunnel test are compared.The results proves that the optimization is effective, the theory and the technique used in optimization of the underwater vehicle main form design are credible.