Multidisciplinary Design Optimization Of Hydraulic Turbine Rotor Considering Multi-source Uncertainty

In order to improve the safety of complex engineering systems,Multidisciplinary Design Optimization（MDO）considering multi-source uncertainty is becoming a research focus.To account for design optimization with aleatory and interval uncertainty,a Reliability based Multidisciplinary Design Optimization（RBMDO）model expressed in terms of Performance Measure Approach（PMA）is derived in this thesis.Meanwhile,Multidisciplinary Reliability Analysis（MRA）and optimization solution theory research are carried out in this thesis.Finally,the method proposed in this thesis is applied to a turbine rotor,and the engineering application research is carried out.The main research contents and innovative achievements of the thesis include the following aspects:（1）RBMDO Mathematical Model Based on PMA.In order to avoid the defect that the reliability index method（RIA）solves the actual reliability and increases the computational efficiency,an optimization model based on the performance function representation is proposed by combining the PMA and RBMDO methods.Compared with the traditional RIA-based model,the proposed model has higher computational efficiency and better robustness.（2）MRA method under aleatory and interval uncertainty.For MDO with aleatory and interval uncertainty,in order to avoid the neglect of interval uncertainty,the MRA method under aleatory and interval uncertainty is proposed.The proposed method makes use of all available information to the greatest extent compared to methods that only consider aleatory uncertainty.In order to meet the actual requirements of the calculation results,the worst reliability of the interval variable within its value range is calculated.（3）Multidisciplinary optimization method under aleatory and interval uncertainty.For MDO with aleatory and interval uncertainty,based on the PMA-based RBMDO model,the Sequential Optimization and Reliability Assessment（SORA）method is used for decoupling.The corresponding method proposed in this thesis is used to independently perform uncertainty analysis and optimization.Compared with the traditional multidisciplinary optimization method under mixed uncertainty,the proposed method improves the solution efficiency.（4）MDO of a turbine rotor considering aleatory and interval uncertainty.A large number of uncertainties exist in the design,manufacture and operation environment of the turbine rotor.The above-mentioned uncertainties are quantitatively analyzed by the proposed MRA method under aleatory and interval uncertainty.Meanwhile,the RBMDO problem of the turbine rotor mechanism is solved by the proposed optimization method under aleatory and interval uncertainty.Through the finite element simulation analysis of the optimized design scheme,the rationality and feasibility of the obtained results are verified.