一种水轮机应变检测仪的设计

针对水轮发电机组在运行不久后就出现叶片裂纹的情况,分析了水轮机叶片裂纹产生的原因,通过设计水轮机应变检测仪能够对水轮机叶片维护及提高水轮机的使用寿命具有直接指导作用,具体介绍了应变测量原理,最后,给出了应变检测仪的设计思路和系统的软件、硬件组成。经过对水轮机叶片的现场监测,应变检测仪达到了设计要求。     

通用集成优化软件SiPESC.OPT的设计与实现

为实现针对复杂工程设计的具有通用设计目标和开放性的优化软件的自主研发,设计并实现面向通用优化计算需求的SiPESC.OPT软件.讨论优化软件开发在优化算法、试验设计和替代模型等方面的需求;设计具有应用层、中间层和核心层的SiPESC.OPT软件架构;根据该软件架构将SiPESC.OPT的功能模块划分为优化任务设计模块、试验设计与近似模型模块、求解器模块、后处理模块和子系统集成模块等.引入优化模型状态类以解耦优化模型类与优化算法类之间密切的依赖关系.风力发电机叶片优化算例和水轮机模型替代算例表明,SiPESC.OPT具有操作简单、功能全面和可扩展性强等特点,可用于复杂优化问题的求解.     

基于参数化的涡轮叶片三维气动优化仿真

为了提高涡轮叶片的设计效率,在分析已有涡轮叶片截面线参数化造型技术优缺点的基础上,基于B样条曲线实现了涡轮叶片截面线的参数化造型和参数化修改,并编写了叶片造型程序,实现了叶片流场模型的自动化生成.以某型号涡轮叶片为例,对其进行三维流场数值模拟,然后采用遗传算法和序列二次规划法算法的组合,以涡轮的气动效率为目标函数,对涡轮叶片进行了气动优化.算例结果表明文中所建立的涡轮叶片自动优化设计体系是可行的.     

基于接触应力的高参数汽轮机叶片枞树形叶根型线优化

为提高汽轮机叶片叶根型线的设计效率和产品质量,基于接触应力约束下的枞树形叶片叶根型线设计,将传统的基于经验的设计与经典优化理论相结合,推导适合叶根型线的设计方法。采用移动渐近线法（method of moving asymptotes, MMA）进行结构拓扑优化,以某低压末级动叶片设计为例,优化前、后叶根和轮槽的VON Mises应力对比表明,所推导的方法能够快速得到所需的型线设计。该设计使得叶根与轮槽间的接触应力降低,叶片的使用寿命提高。     

基于VB的风力机叶片外形优化设计

为了实现风力发电机风轮叶片外形的优化设计,以风场风速分布为基础提出了综合优化目标;以片条理论为基础提出了以展弦比为关键参数的修形约束条件的气动优化目标,建立了叶片外形优化设计的数学模型.采用枚举法和循环结构,选用Access数据库,应用Visual Basic编制程序实现叶片外形的优化设计.针对内蒙古某地区设计了1.5MW风力机叶片,与国外同功率某通用叶片进行了对比分析.结果表明,两种叶片外形基本吻合,而且文中设计的叶片在性能上有明显优势,同时也验证了文中提出数学模型的可靠性和程序的实用性.     

大型混流式叶片的多轴联动数控加工编程技术

一、引言 水轮机是水力发电的原动机,水轮机转轮叶片制造的优劣对水电站机组的安全、可靠、经济性运行有着巨大的影响.水轮机转轮叶片是非常复杂的雕塑面体.长期以来采用的"砂型铸造→砂轮铲磨→立体样板检测"的制造工艺,不能有效地保证叶片型面的准确性和制造质量.     

轴流压气机叶片优化仿真系统的开发

为了进一步提高压气机性能,需要对现有压气机叶片进行快速改型设计.为满足叶片快速改型设计的需要,着重论述了系统仿真原理、系统功能和实现方法,综合运用叶片造型、流场数值仿真和神经网络优化技术,采用面向对象、模块化等软件开发方法,设计并开发了一套叶片优化仿真软件系统,使其具备叶片造型设计、性能仿真和优化等功能,并给出了某叶栅叶片的优化改型实例.仿真结果表明,能改善压气机的气动性能、提高设计效率,较好地满足了压气机叶片优化仿真需求,具有良好的工程应用前景.     

基于免疫遗传算法的水机调节参数优化与仿真

水轮机调速器是保证水电站机组稳定运行和电能质量的控制设备，如何选取水轮机调速器的最优参数，是影响到调节系统质量和电能质量的一个重要的问题。针对当前使用遗传算法优化水轮机调速器参数存在寻优效率不高的问题，提出了一种用免疫遗传算法优化水轮机调速器参数的新方法。通过借鉴生物体免疫系统中的回忆应答和人工主动免疫的原理，减少遗传算法中的退化现象，提高寻优效率和适应性。将新算法应用于某水轮机仿真，仿真结果表明，免疫遗传算法不依赖于参数的初值，寻优效率较典型遗传算法有明显提高，具有很强的鲁棒性和适应性。     

基于VB的风力机叶片外形优化设计

为了实现风力发电机风轮叶片外形的优化设计,以风场风速分布为基础提出了综合优化目标;以片条理论为基础提出了以展弦比为关键参数的修形约束条件的气动优化目标,建立了叶片外形优化设计的数学模型。采用枚举法和循环结构,选用Access数据库,应用Visual Basic编制程序实现叶片外形的优化设计。针对内蒙古某地区设计了1.5MW风力机叶片,与国外同功率某通用叶片进行了对比分析。结果表明,两种叶片外形基本吻合,而且文中设计的叶片在性能上有明显优势,同时也验证了文中提出数学模型的可靠性和程序的实用性。     

大型水轮机转轮叶片的五轴加工技术

大型水轮机转轮叶片的五轴联动加工技术,是表征水轮机制造水平的重要标志之一。转轮叶片是水轮机关键部件,其制造精度对机组的效率等水力性能有直接的影响,因此型面加工要求精度高。国内水轮机叶片制造长期采用砂型铸造,经手工铲磨成型和采用立体样板检测的工艺方法,但手工铲磨的方式,不但劳动环境恶劣、劳动强度大、效率低,而且叶片型面质量差,降低了水轮机的效率。     

Design of heterogeneous turbine blade

Constantly rising operating pressure and temperature in turbine drivers push the material capabilities of turbine blades to the limit. The recent development of heterogeneous objects by layered manufacturing offers new potentials for the turbine blades. In heterogeneous turbine blades, multiple materials can be synthesized to provide better properties than any single material. A critical task of such synthesis in turbine blade design is an effective design method that allows a designer to design geometry and material composition simultaneously.This paper presents a new approach for turbine blade design, which ties B-spline representation of a turbine blade to a physics (diffusion) process. In this approach, designers can control both geometry and material composition. Meanwhile, material properties are directly conceivable to the designers during the design process. The designer's role is enhanced from merely interpreting the optimization result to explicitly controlling both material composition and geometry according to the acquired experience (material property constraints).The mathematical formulation of the approach includes three steps: using B-spline to represent the turbine blade, using diffusion equation to generate material composition variation, using finite element method to solve the constrained diffusion equation. The implementation and examples are presented to validate the effectiveness of this approach for heterogeneous turbine blade design.     

Development of a structural optimization strategy for the design of next generation large thermoplastic wind turbine blades

This paper presents the development of a structural optimization process for the design of future large thermoplastic wind turbine blades. The optimization process proposed in this paper consists of three optimization steps. The first step is a topology optimization of a short untwisted and non tapered section of the blade, with the inner volume used as the design domain. The second step is again a topology optimization, but on the first half of a blade to study the effect of non symmetry of the structure due to blade twist and taper. Results of this optimization step are then interpreted to build a shell model of the complete blade structure to perform composite size optimization based on a minimum mass objective subjected to constraints on deflection, composite strength and structural stability. Different blade models using ribs are then optimized and compared against conventional blade structure (box spar structure without ribs and single web structure without ribs). The use of ribs in wind turbine blade structures, which is more adapted to thermoplastic composite manufacturing than for thermoset composites, leads to slightly lighter blades than conventional blade structures.     

Structural design of modern steam turbine blades using ADINA™

The present paper provides an overview of the structural design of modern steam turbine blades at Siemens power generation using the finite element code ADINA™. The different types of blades are described in detail regarding their geometry and loading. The modular building block approach of modelling is shown to be of essential importance. For the different analyses a fatigue post-processor has been implemented as well as an optimization tool. Both of these in-house codes will be briefly presented.     

Reverse engineering in the design of turbine blades – a case study in applying the MAMDP

This paper presents a case study on the reverse engineering of turbine blades used in nuclear power generators. Reverse engineering has been widely recognised as a crucial step in the product design cycle. However, major problems with current reverse engineering technology are the inefficient surface reconstruction process, lack of digitising accuracy control in the data digitisation process, and bottlenecks resulted from huge amounts of digitised surface points in the surface modeling process. Moreover, under this limitation, modern concurrent engineering concepts are difficult to implement to obtain optimal product design. This study applies a developed reverse engineering approach – the modified adaptive model-based digitizing process (MAMDP) to the 3D geometric design of turbine blades. The approach integrates surface digitising and modeling processes of turbine blades into a single surface reconstruction process. Using the approach, accurate product CAD models can be efficiently generated and the product design cycle of turbine blades can be successfully linked.     

Inspection of assembly error with effect on throat and incidence for turbine blades

Turbine blades are the key aerodynamic parts and most widely used in turbomachinery. Rather than working individually, turbine blades are assembled on the rotor of turbomachinery to constitute bladed disks as the basic working units. Therefore, the quality of turbine blade assembly is crucial for guaranteeing the long and safe operation of turbomachinery with good performance. Aiming at this critical issue, two assembly error specifications of turbine blades are firstly defined as Circumferential Indexing Error and Axial Positioning Error, which are key factors affecting the throat and the incidence of turbine cascade. Then, the corresponding feature-based analysis methods are presented in this paper. Finally, the proposed theory and methods are experimentally verified through the bladed disk of a steam turbine rotor. The results demonstrate that the two defined assembly error specifications of turbine blades can be effectively extracted using the proposed methods. The assembly error of turbine blades can be used to evaluate the aerodynamic performance and the operating safety of turbine. Moreover, a guide can also be provided for the subsequent adjustment and correction of turbine blade assembly.