大型立式混流泵开式叶轮叶片的模态分析

对电厂中大型立式混流泵开式叶轮叶片的断裂事故，应用模态分析技术用实验方法测出了叶片的模态频率及其振型。找出叶片断裂原因是因发生二阶共振而引起疲劳破坏。此模态测试方法可直接在被测体上画出其各阶振动节线，为大型泵的开式叶轮叶片设计提供可靠参考依据。     

加工轴流泵叶轮座的高效工装

轴流泵转子部件上的叶轮座,是轴流泵的关键零件,加工精度要求高.通常在卧式镗床上或加工中心上完成加工.由于叶轮座体积和重量一般都不太大,选用的加工设备能力过剩,造成制造成本加大.所以通过采用专用工装,在普通车床上加工,大大降低了生产成本.     

一种实用的混流泵叶轮设计方法

在对优秀水力模型统计的基础上，利用一元流动理论的基本思想，按照离心泵叶轮的设计思路，对设计过程中的重要参数如叶轮出口宽度，叶轮外径、叶片出口角等的选取进行了修正，提出了一种实用的混流泵设计方法。     

浅谈混流泵叶轮专用拆卸装置

传统的城市排水使用的混流泵叶轮拆卸方法，费力费时及泵轴很难再利用，本文介绍的是一个便于携带和使用的混流泵叶轮专用拆卸装置。     

混流泵叶轮切割规律的试验研究

经过对混流泵叶轮多次切割试验,探讨了叶轮切割量与泵的流量、扬程之间的关系,总结了混流泵叶轮切割后的性能变化规律,进而对现有公式进行了修正.     

叶轮加工工艺与装夹方案

分析讨论了立式混流泵的叶轮的用途和工作条件。根据叶轮的材料、结构特点和技术要求,进行加工工艺性分析,了解其加工技术难点,进而提出拟采取的加工技术方案,提出了在叶轮上下端增设工艺所需要的工艺环的毛坯的改进型及其加工工艺方案,并在分析讨论一般压板式装夹各种问题的基础上,设计开发了一种专用夹具模子以满足叶轮加工要求。采用该装夹方案,不仅达到了图纸的零件加工精度和形位公差要求,而且叶轮的加工效率也得到很大的提高。     

混流泵叶轮的水力设计方法研究

本文利用目前著名的水泵设计软件完成一台混流泵叶轮的水力设计。此法与以往传统的设计方法相比具有明显的技术优势。利用该软件设计,不仅大大缩短了研制周期,同时可以给定来流冲角、精确控制载荷分布,提高了叶轮水力设计准确性。CFD流动计算分析结果表明设计的叶轮具有优越的流动性能和高的效率。     

混流泵叶轮三元可控速度矩的设计

介绍了一种混流泵叶轮叶片的设计方法——准三元设计法.该方法是以速度矩Vur为控制变量,通过正反问题迭代计算,从而构制出叶片,力求使叶轮叶片形状与叶轮内实际流态相吻合,从而得到性能优异的混流泵.     

混流泵叶轮中水力摩擦阻力的分析计算

根据有关离心泵径向叶轮流道的水力摩擦损失的计算公式，结合混流果叶轮模型的特点，导出了具有一定理论型线的混流叶轮流道的水力摩擦阻力计算公式，并通过实例进行了验算。     

三元叶轮在轮盖上铣制叶片的加工工艺

一、前言一般闭式三元叶轮的叶片铣在叶轮的轴盘上 ,然后采用开槽焊和钎焊的方法将叶片与盖盘焊在一起 ,这已经成为比较成熟的加工工艺用于实际生产中。但由于三元叶轮结构形式的不同 ,为降低焊接难度、制造成本和提高叶轮制造质量 ,可采用三元叶片铣在盖盘上这种新的加工工艺。二、叶轮的结构特点首先要定制叶片入口处的直纹面方向 ,如果刀具在叶片入口沿直纹面方向与叶轮的盖盘或对面的叶片发生干涉的话 ,这种叶轮从加工角度来讲是不可行的。其次这种叶轮的典型结构特征为叶片入口处扭曲 ,而且在此处盖盘面曲率较大 ,叶片出口侧形似二元轮…     

High performance hydraulic design techniques of mixed-flow pump impeller and diffuser

In this paper, we describe a numerical study about the performance improvement of a mixed-flow pump by optimizing the design of the impeller and diffuser using a commercial computational fluid dynamics (CFD) code and design-of-experiments (DOE). The design variables of impeller and diffuser in the vane plane development were defined with a fixed meridional plane. The design variables were defined by the vane plane development, which indicates the blade-angle distributions and length of the impeller and diffuser. The vane plane development was controlled using the blade-angle in a fixed meridional plane. The blade shape of the impeller and diffuser were designed using a traditional method in which the inlet and exit angles are connected smoothly. First, the impeller optimum design was performed with impeller design variables. The diffuser optimum design was performed with diffuser design variables while the optimally designed impeller shape was fixed. The importance of the impeller and diffuser design variables was analyzed using 2^k factorial designs, and the design optimization of the impeller and diffuser design variables was determined using the response surface method (RSM). The objective functions were defined as the total head (Ht) and the total efficiency (?t) at the design flow rate. The optimally designed model was verified using numerical analysis, and the numerical analysis results for both the optimum model and the reference model were compared to determine the reasons for the improved pump performance. A pump performance test was carried out for the optimum model, and its reliability was proved by a comparative analysis of the results of the numerical analysis and an experiment using the optimum model.     

Multi-objective optimization for mixed-flow pump with blade angle of impeller exit and diffuser inlet

During design optimization, the impeller and diffuser of a mixed-flow pump are generally optimized separately. In such cases, the total head can be overdesigned. In this study, the designs of the impeller and diffuser were optimized simultaneously by using computational fluid dynamics and the Response surface method (RSM). Design variables were defined according to the vane plane development of the impeller and diffuser. Three-dimensional Reynolds-averaged Navier–Stokes equations for the shear stress transport turbulence model were discretized by finite volume approximations and solved on hexahedral grids to analyze the flow in the pump. The total head and total efficiency were selected as objective functions, with four design variables related to the impeller outlet angles and diffuser inlet angles used for optimization. The RSM was constructed based on the objective functions with design points generated from the central composite method. The hydraulic performance of the optimum model was analyzed.     

Design optimization for mixed-flow pump impeller by improved suction performance and efficiency with variables of specific speeds

In this study, the shape of a mixed-flow pump impeller and its flow characteristics as a function of the specific speed are studied to improve its suction     

水泵叶轮模型的改进与发展

为了使水泵叶轮模型准确，以减少能耗。针对叶轮模型的制作过程进行讨论，涉及绝大多数水泵厂的叶轮模型制作工艺过程，以及未来水泵叶轮模型的设计方法和注意的问题。     

离心泵叶轮切割

通过实践总结出一种快捷、可靠曲离心泵叶轮切割方法。     

基于分片侧铣法的整体叶轮数控加工

根据科研工作实际，提出了一种新的整体叶轮数控加工方法--分片侧铣法，利用该方法可有效地提高叶轮的加工效率和质量，并给出了基于该方法的加工实例。     

离心泵叶轮叶片的加工方法研究

此篇论文主要写了叶轮直纹叶片在DMU-70eV的五轴数控铣中的加工方法.首先介绍了叶片的造型方法,通过木模截线图和轴面投影图获取型值点进行三维造型;然后根据叶片成型原理来进行刀路规划,让工作台旋转至合适角度,使刀具能够沿轴面截线方向走刀;接着详述了刀距和刀具加工起始点坐标的计算方法,通过B样条曲线插值方法来求新的型值点坐标;最后编写刀路,并进行加工模拟仿真.     

超大直径薄环机加工艺及工装夹具

论述采用特殊U形夹具加工大直径薄壁环形件的加工工艺。     

半开式叶轮离心泵的效率优化与分析

为了提高半开式叶轮离心泵的水力效率,应用速度系数法对半开式叶轮离心泵的水力效率进行了优化,并采用k-ε湍流模型和标准壁面函数对离心泵进行了数值模拟,仿真分析了蜗壳和叶轮顶端问不同间隙以及不同叶片数对离心泵水力效率的影响。研究结果表明,当蜗壳与叶轮顶面的间隙为0．5mm,叶片数为6时,离心泵的效率较好。     

Failure analysis of melt urea pump impeller

Abstract

A melt urea pump is out of work after only 6 days in service. The failure of the melt urea pump impeller is analysed using different methods including chemical composition analysis, metallographic observation, SEM and energy dispersive spectroscopy analyses, etc. The results show that the material of the impeller is not the reported AISI 321 stainless steel but AISI 316 stainless steel. There are many honeycombed holes on its impeller, which is the typical feature of cavitation damage. Therefore, the main failure reason of the impeller is the cavitation erosion, and the electrochemical corrosion of the medium also accelerated the failure of the impeller. The failure of the impeller is not related with the as casted defects of the material because no obvious as casted defects are found in the material.