Design Of The Lines Of Underwater Vehicles Based On Collaborative Optimization

The design of lines is an important content of the overall design of an underwater vehicle.Well-design lines can not only improve the underwater vehicle’s hydrodynamic performances,but also reduce the energy consumption.Traditionally,the optimization design of lines mainly adopts the solitary discipline optimization design,which not only ignores the interrelationship and coupling effect between different disciplines,but leads to time consumption in the design.Furthermore,the global optimization solution is hard to guarantee after the optimization process.The dissertation applies an engineering system theory into the optimization design of lines for an underwater vehicle.Research works in this dissertation are summarized as follows.Firstly,this dissertation discusses the background and significance of the research project,and addresses the state-of-the-art of the research progresses of the underwater vehicle’s lines design.Combined with the design processes of the underwater vehicle,the limitations of traditional design methods had been pointed out.The feasibility and necessity of the application of Multidisciplinary Design Optimization(MDO)to the design of the lines of underwater vehicle had been stated.Secondly,the modeling idea and process of the Generalized Collaborative Optimization(GCO),one of the MDO’s methods,are introduced in detail.By using GCO,the calculation difficulties caused by consistency constrains can be solved successfully.Take the optimization of gear reducer as an example,the optimization result shows the effectiveness and superiority of the GCO method’.Meanwhile,Computational Fluid Dynamics(CFD)is used in numerical test.Simulations are performed for straight-forward tests、oblique towing tests、rotating arm tests with SUBOFF 5470 bare hull and fully appendages.By comparing the simulation results with trial data,it can be concluded that the requirement of engineering forecast accuracy can be satisfied.Therefore,it can be stated that the computational domain,meshing and numerical methods used in this dissertation are reliable.Furthermore,an approximate model is constructed based on the Optimal Latin Hypercube design(Opt LHD)and Radial Basis Function(RBF).The fitting accuracy is verified by a test case and the approximate is applied to the GCO framework.The approximate model method can not only simplify the system,but also meet the requirement of the design accuracy in the design stage.Finally,taking Isight software as a platform,a generalized collaborative optimization(GCO)framework is set up based on sub-disciplines,i.e.the rapidity and the manoeuvrability.Software and author-edited-programming are integrated in the platform.SUBOFF 5470 model is taken as a verification model and applied to the design of lines in the GCO framework.Optimization results provided several feasible designs scheme and the optimal design parameters of the underwater vehicle’s line.