混流式水轮机转轮设计变量耦合强度分析

发布时间：2019-03-10 19:14

【摘要】：在开展混流式水轮机转轮的多学科优化时通常需要进行设计变量的学科耦合强度分析,以便为建立简洁、高效的多学科优化求解策略提供依据。该文提出了一种基于全局相对灵敏度的转轮设计变量耦合强度分析方法,该方法基于参数化全三维反问题设计理论实现对转轮几何的参数化控制,并通过改进后的MorrisOAT法进行各学科目标函数对转轮设计变量的全局相对灵敏度计算,然后以各设计变量的全局相对灵敏度集合为论域,引入模糊隶属度函数量化计算设计变量对各学科目标函数的隶属度。最后,以各设计变量的隶属度值为基础,提出了设计变量的耦合强度判定准则,为设计变量的耦合程度属性确定提供了参考。采用该文所提出的分析方法对某混流式水轮机模型转轮的设计变量开展了耦合强度分析,并根据变量的耦合强度分析结果开展了转轮的优化设计,优化后的转轮不仅使得水轮机在3个优化工况下的水力效率分别提高0.2%、0.82%和1.2%,同时叶片的空化和强度性能也得到改善,该结果表明该文所提出的混流式水轮机转轮设计变量耦合强度分析方法能可靠有效的界定各设计变量的耦合程度属性,从而验证了方法的可行性。
[Abstract]:When the multidisciplinary optimization of Francis turbine runner is carried out, it is usually necessary to analyze the disciplinary coupling strength of design variables in order to provide a basis for the establishment of a concise and efficient multidisciplinary optimization solution strategy. In this paper, a method of coupling strength analysis of runner design variables based on global relative sensitivity is presented. The parametric control of runner geometry is realized based on parametric three-dimensional inverse problem design theory. The improved MorrisOAT method is used to calculate the global relative sensitivity of the objective function to the design variables of the runner, and then the global relative sensitivity set of each design variable is taken as the domain. The fuzzy membership function is introduced to quantitatively calculate the membership degree of the design variables to the objective functions of various disciplines. Finally, based on the membership values of each design variable, a criterion for determining coupling strength of design variables is proposed, which provides a reference for determining the coupling degree attributes of design variables. The coupling strength analysis of the design variables of a Francis turbine model runner is carried out by using the analysis method proposed in this paper, and the optimum design of the runner is carried out according to the coupling strength analysis results of the variables. The optimized runner not only increases the hydraulic efficiency of the turbine by 0.2%, 0.82% and 1.2% under three optimized conditions, but also improves the cavitation and strength performance of the blade. The results show that the coupling strength analysis method for Francis turbine runner design variables can reliably and effectively define the coupling degree attributes of each design variable, thus validating the feasibility of the method.
【作者单位】：西安理工大学水利水电学院;
【基金】：国家自然科学基金项目(51379174、51679195);国家自然科学基金重点项目(51339005)
【分类号】：TK733.1

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