| Deep ocean development is one of the most important development strategy in the21stcentury, especially for deepwater offshore and deep-sea vehicle. Preliminary design andoptimization of Unmanned Underwater Vehicle(UUV) takes an important role in the wholedesign cycle, of which system coupling is so complicated that higher precision ofmathematical modeling and efficient optimization are needed in its design project.UUVperformances of rapidity, maneuverability, energy system and control tank are researched ofwhich the voyage is100kilometers and the depth is2000meters, Based on whichcomprehensive optimization mathematical model and high efficiency parallel hierarchicaloptimization algorithm are put forward while system objective function is established byanalytic hierarchy process(AHP) and fuzzy evaluation method. Optimization softwaresystem is formed using C++language, on account of which optimized results are analyzed.Research work is summarized below:1.Five kinds of typical rotary linear lines of UUV naked hull such as AUTOSUB,REMUS, BLUEFIN which head line is parabolic or vertical,HUGIN are chosen whichappendix is only cross rudder or cowling. Resistance numerical simulation is conductedwhile turbulence model is SST-kω, the results of which are validated by which arecalculated theoretically by ITTC formula. Two blade propeller is designed by lifting linetheory and performance is researched by experiment. Finally, rapidity subsystem is formedoptimization of which reveals AUTOSUB type resistance during2-5kn takes a goodperformance. Regarding of placement and capacity, circular bottom of UUV middle hull isreplaced of flat shape while dimensionless numeric line is obtained. Principal dimensionsvalue of head, middle, after part,diameter are scattered while135FEM models isestablished for resistance calculating including1080design conditions. Response Surface ofcoefficient of viscous pressure and fraction is constructed by dimensionless analysis andmultivariate curve fitting analysis. Ultimately. rapidity of optimization subsystem is formed.2.Flexibility and stability of vertical plane and horizontal plane control is studied. Mainhull hydrodynamic derivatives is calculated by estimating added mass coefficient.Appendage hydrodynamic derivatives are estimated based on thin airfoil theory. UUVhydrodynamic derivatives are obtained including acceleration, linear and angular velocity,rudder hydrodynamic performance. Sub-model of maneuverability is built including13indexes. Horizontal stability indexes include angle of attack statically indeterminatecoefficients, vertical dynamic stability criterion, deep linear motion trim angle and rudderangle, minimum characteristic root of stability vertical equation. Horizontal mobilityindexes include rise rate, inverse velocity and initial turning time of vertical movement. Vertical stability indexes include drift angle of statically indeterminate coefficients, linearmotion stability criterion, minimum characteristic root of horizontal stability equation.Vertical mobility indexes include constant rotary steering index and initial turning time ofhorizontal movement. Maneuvering system total objective function is constructed based onhierarchy analysis and fuzzy evaluation method.3.Energy system performance and constraints needed to satisfy is studied includingbattery box power configuration, circuit connection and geometric arrangement. Energysystem consumption includes control electricity and power electricity. On the one handBattery box need to meet the demand of vehicle system voltage, on the other hand meetingthe vehicle energy constraints and energy tank geometric constraints. Efficiency of circuitand energy reserves of control electricity and power electricity adding weight ratio ofenergy are chosen as optimizing indexes of energy system.4.Tank pressure shell system is conducted while specific mass is chosen as indexaccording thin shell theory. Constraints of strength including middle point and both ends ofarticle shell beam. Conditions of stability contains local stability of inter frame shell andoverall stability of cylindrical shell. At last,Subsystem optimization mathematical model ofcontrol tank is put forward.5.Optimization algorithm of parallel and hierarchical strategy is elaborated whileoptimization space constraint relaxation strategies and parallel optimization algorithm basedon the key variables is raised. Basic theory of the process of chaos algorithm(CA), geneticalgorithm (GA) is researched of which program is written by C++. Parallel hybrid layeredalgorithm based on genetic algorithm of UUV mathematical model is proposed coveringparallel genetic algorithms, hierarchical genetic algorithm and hybrid genetic Tabu searchalgorithm. Comprehensive analyzing four subsystems, overall optimization mathematicalmodel is put forward. according to the impact of optimal design variables on the systemdesign is divided into system level design variables, subsystem coupling variables andsubsystem internal variables. Overall objective function is presented based on mathematicalmodel using AHP and Fuzzy method. after optimization of different algorithms, integratedoptimization effect of layed genetic algorithm is best, of which subsystem joint optimizationis conducted which turns out general objective function is the most sensitive of weight ofrapidity subsystem. |
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