SolidWorks中换热器管板三维参数化设计

在研究了管壳式换热器管板三维建模方法和自动布管原理的基础上,使用Visual Basic 和Microsoft Access对SolidWorks进行二次开发,采用系统参数化建模和程序参数化建模相结合的方法对管板进行三维参数化建模.同时,利用修改工程图参考的方法实现了工程图的自动绘制.软件具有良好的适应性、人机交互性及扩充性,提高了设计效率和质量.     

基于SolidWorks的金属导管三维参数化建模研究

介绍SolidWorks软件二次开发的方法与关键技术,给出金属导管三维参数化建模的思路与方法,利用Visual C++6.0中ATL的方式对SolidWorks2008进行二次开发,实现金属导管三维参数化建模过程,结果表明利用SolidWorks二次开发进行三维参数化建模的优越性。     

基于SolidWorks的包装容器结构参数化设计实现

探讨了通过Visual Basic6.0(VB)用户界面对SolidWorks进行尺寸驱动,以实现中空塑料瓶的结构三维参数化设计的思路,利用SolidWorks提供的应用程序接口(API),通过直接输入相关设计参数,自动实现产品的三维建模。对包装容器结构的结构设计有一定的借鉴作用。     

基于SolidWorks的包装容器结构参数化设计

主要介绍了采用SolidWorks二次开发实现塑料固体药瓶的结构三维参数化设计,实现了直接输入参数后自动实现产品的精确造型,使包装工程技术人员对SolidWorks在包装结构参数化设计的应用有一个明确的了解,对其他材料的包装容器结构的三维参数化设计有着很大的借鉴作用.     

椭圆类齿轮参数化设计与运动仿真系统的开发

非圆齿轮因其节曲线为非圆形,计算复杂,设计困难,目前的三维设计软件都无法直接进行实体建模。根据非圆齿轮的设计理论,利用Visual Basic 6.0良好的界面设计功能和计算能力对SolidWorks进行二次开发,设计出椭圆类齿轮参数化设计与运动仿真系统,实现了椭圆类齿轮的三维参数化建模与运动仿真。论述了系统的开发过程,运行实例表明系统界面友好,设计正确。解决了椭圆类齿轮设计中的复杂计算和三维实体造型难的问题,可提高设计精度、缩短产品开发周期,保证产品质量。     

SolidWorks中的非圆齿轮实体建模方法研究

非圆齿轮因其节曲线为非圆形,目前的三维CAD软件还无法直接进行实体建模.研究了非圆齿轮轮齿设计方法及计算方程,采用Visual Basic语言进行SolidWorks二次开发,论述了系统开发的具体过程.以常用的椭圆齿轮为例实现了参数化实体建模.     

印刷机前规机构三维参数化调整

为了使通用三维设计软件更加适合行业特点,使用更加方便、快捷,应用VB对通用三维设计软件SolidWorks进行了二次开发.建立机构的三维模型,从中读入机构配合的数据变量,应用程序驱动法,通过对SolidWorks API函数的调用,用新的设计变量值更新模型,实现印刷机前规机构的三维参数化调整,模块直接挂在SolidWorks的菜单下,界面统一、操作方便.     

基于 SolidWorks的纸浆模塑盘状衬垫参数化设计

目的为了节约设计成本,提高设计效率,缩短设计周期,基于当下流行的三维设计软件SolidWorks,研究开发设计出一套参数化设计纸浆模塑包装制品的快捷方法。方法以圆台状结构作为缓冲单元的盘状纸浆模塑制品为例,在SolidWorks中采用宏录制的方法,按照逻辑顺序特征建模后,分离出盘状纸浆模塑包装衬垫制品的设计参数,并通过SolidWorks API使用Visual Basic平台实现人机的交互化。结果最终以插件的形式安装在SolidWorks中,运行软件后在弹出窗口中输入产品尺寸参数值,即可实现快速准确地设计可靠的纸浆模塑包装制品。结论基于SolidWorks二次开发形式的参数化设计模式,为高效可靠设计纸浆模塑提供了新的设计思路。     

基于SolidWorks的离心通风机叶轮参数系列化建模

叶轮是离心通风机产品的核心部件,结构形状复杂,本文主要通过SolidWorks对离心通风机叶轮的参数系列化建模进行了探讨,并针对离心通风机各形式叶轮建模过程的特征进行了阐述,从而提升设计质量和效率。     

UG参数化设计加工——罗茨鼓风机叶轮曲面

本文阐述了基于UG生成表驱动的三维参数化设计,并对罗茨鼓风机叶轮建立参数化模型、确定设计变量、给模型分配设计变量以及设置和编辑电子表进行了详细的论述,运用UG数控编程。生成加工程序。实践证明,利用此方法可以方便快捷地建立叶轮的三维参数化模型库,以实现叶轮的系列化设计,能大大提高设计效率。     

A FINITE ELEMENT PERTURBATION METHOD FOR COMPUTING FLUID-INDUCED FORCES ON A CENTRIFUGAL IMPELLER ROTATING AND WHIRLING IN A VOLUTE CASING

A finite element based method has been developed for computing time-averaged fluid-induced radial excitation forces and rotor dynamic forces on a two-dimensional centrifugal impeller rotating and whirling in a volute casing. In this method potential flow theory is used, which implies the assumption of irrotational inviscid flow. In comparison with other analyses of fluid-induced impeller forces, two main features have been included. Firstly, the hydrodynamic interaction between impeller and volute isproperly modelled. Secondly, the variation of the width of the volute has been adequately included in the two-dimensional analysis by a modification of the equation of continuity. A regular perturbation method is used to deal with the effects of the whirling motion of the impeller. The excitation forces are calculated from the zeroth-order problem in which the impeller axis is placed at the volute origin. The rotor dynamic forces associated with the whirling motion of the impeller are derived from the first-order solution. The force components, tangential and normal to the whirl orbit, are predicted as functions of the impeller--volute geometry, the flow conditions and the whirl speed ratio. The method is applied to a centrifugal pump experimentally tested at the California Institute of Technology. Comparisons between predictions and experimental data show the capabilities of the proposed method to reproduce the main features of fluid-induced impeller forces in centrifugal pumps. © 1997 by John Wiley & Sons, Ltd.     

离心泵转子动力学模型中流体力的简化

采用叶轮流体力的简化方式可以提高离心泵流体激励诱发振动的计算的准确程度。根据达朗伯原理对试验台架建立了包含离心泵基座的四圆盘三轴段转子动力学模型;将流体力分别简化为叶轮内20 %流体质量、40 %流体质量、CFD集中力与力矩,采用Newmark-隐式算法对转子动力学模型进行瞬态响应分析。结果表明,将叶轮上流体力简化为CFD;所得集中力与力矩时;可有效得出离心泵运转过程中流体激励所诱发的基座振动。而所获得的基座振动位移与加速度幅值均远大于将流体力简化为叶轮内20 %或40 %流体质量所获得的基座振动数值。另一方面,将流体力简化为叶轮内40 %流体质量所获得的基座振动大于简化为叶轮内20 %流体质量所获得的基座振动。     

离心叶轮滑移系数算法分析

简介离心叶轮滑移系数的产生及6个经验计算公式。通过不同离心叶轮试验数据与滑移系数6个经验公式计算结果的比较及误差分析,对滑移系数计算经验公式的使用范围进行归类,为叶轮计算方法的优化提供设计依据。     

两种二元离心叶轮型线优化方法比较

以二元离心风机叶轮叶片型线为研究对象,对7—40和bb24风机叶轮运用等减速和等当量扩张角规律,分别对其进行叶片型线的重新设计,并运用CFD数值模拟叶轮内部复杂三维流动。结果表明,在设计工况下,无论是等减速规律还是等当量扩张角规律对于2个不同的风机叶轮都取得了较好的效果,尤其是应用等减速规律改进的叶轮,改进效果更加明显,叶轮性能显著提高。     

Distinctive feature of self-oscillations (surging) of impeller pumps

It has been established experimentally and confirmed analytically that before the stall of a centrifugal impeller pump, self-oscillations (surging) of the pump are set up in the region of ascending cavitation branchings of its monotonically decreasing head characteristic. Beyond this region, the pumping mode of such a pump is absolutely stable. It has been established that changes in the nonstationary operation of a centrifugal impeller pump produced by variation of its wave resistance are diametrically opposite in character in cavitation and cavitation-free modes.     

Influence of the new refrigerant thermodynamic properties on some refrigerating turbocompressor characteristics

Comparison of the main geometrical and operating parameters of centrifugal compressors working with various refrigerants is realised in this paper. The interdependence between the centrifugal compressor pressure ratio, compression work, impeller peripheral speed, Mach number, compressor capacity, impeller diameter and width, speed of rotation, and refrigerant molecular mass, normal boiling temperature and specific volumetric cooling capacity for various refrigerants are shown and discussed. The flow phenomena in the turbocompressor flow field, caused by high Mach number and high pressure ratio, are analysed. Some theoretical observations for the influence of the substitute of the refrigerant on the turbocompressor performance characteristics are presented. The possibilities for the replacement of the refrigerant in the existing refrigerating machines are discussed.     

Development of a centrifugal blood pump with magnetically suspended impeller and the related fluid mechanical problems

This paper deals with fluid mechanical problems encountered in eight years of developmental studies on a centrifugal blood pump with magnetically suspended impeller. The main results of the investigation are as follows. The impeller disk friction is dominant among all the power losses; the magnetically suspended impeller with radial straight vanes is the most stable. Motor current depends on blood viscosity and flow rate. Consequently, the flow rate and pressure difference can be estimated by self-sensing without any need for flowmeter and pressure transducers.     

蜗舌型式对离心通风机气动激励的影响分析

蜗舌是离心通风机重要部位之一,为研究蜗舌型式对离心通风机振动噪声的影响,本文对某型离心通风机进行气动激励的计算仿真。通过定常计算,发现蜗舌结构型式的改进能够改善局部区域的漩涡,减小诱发振动的激励因素;通过非定常计算,发现蜗舌结构型式的改进对离心通风机气动激励的影响主要体现在局部区域压力脉动的改善,尤其是叶轮出口气流激发的叶频脉动的降低。根据计算分析结果对通风机振动噪声变化进行了预估,试验结果表明,蜗舌结构的改进能够降低通风机振动噪声,气动激励数值分析可为通风机低噪声改进效果提供判断依据。     

Fatigue life assessment of centrifugal compressor impeller based on FEA

Fatigue life assessment of centrifugal compressor impellers has been a critical issue in industrial practice and application. In this paper, both centrifugal load and aerodynamic load have been considered in the analysis of the impeller life using finite element analysis (FEA). The analysis showed the regions of stress concentration and the mean stress of the finite element at the maximum stress point. The S–N curve of the impeller is therefore fitted by a computational model. The model is proved to be reliable by comparing the computed results with the experimental data. Thereby the failure mechanism of the impeller can be expressed analytically and its reliability can be assessed online.