Tool path planning and geometry simulation for multi axis CNC belt grinding

Belt grinding machine with multi axis computer number control(CNC) system can effectively process parts with complex moulding surfaces.In this paper,iso parametric and iso planar tool path planning strategies customized for this kind of machine are proposed.The tool path generation methods are designed based on the analysis of the belt grinding process.By using least square method,optimized cross section normal is computed in the iso planar method.To improve the design efficiency of path planning,reduce experiments and increase economical benefit,the geometric simulation program based on linear grinding model is developed.Experiment on a turbine blade profile shows that the proposed algorithms work satisfyingly.     

system modeling and simulation of wind turbines

Wind turbines operate in harsh environment with transient and variable working conditions. As a result, wind turbines are complicated, nonlinear, uncertain systems. Modeling and analysis of these systems are crucial to their design. Based on MATLAB, a new dynamic simulation model of a stalled wind turbine was presented. The blade element momentum theory and the state space method were programmed into MATLAB/SIMULINK to calculate wind turbine aerodynamic performance. The generator was also modeled in MATLAB/SIMULINK, taking the coupling between the generator and the rotor speed into consideration. Based on the proposed MATLAB model, an analysis of a 600 kW wind turbine was carried out. The calculation values were compared with the measured data. The results indicate the correctness of the proposed MATLAB model. The simulation model can be applied to optimize design and control of stalled wind turbines.     

On the New Blade Shape of the Turodrill and Its CAD

Based on the research on the motion law of the drilling fluid along the blade, the necessary condition of the blade shape for a high efficiency turbodrill is obtained. Hence a mathematical model how to design a blade shape has been put forward, and the solution method of the model is obtained, which helps to design a high efficiency turbodrill. What's more, a 3 dimension model of the blade has been set up using Pro/E software, which can link with the advanced computer language by a interface routine and modify the 3-D blade model automatically. Based on the theory, a software has been compiled to design the blade automatically, which can improve the design efficiency and the design quality of the turbodrill.     

Modular Design Base on Variety Theory

Variety Design not only support to short down development time, and cut down development cost, but also support to response marketing rapid, is a kind of modern design theory which apply on Mass Customization. In some way, Variety Design is a kind of design that integrates standard design and modular design, and Variety Design object is high cost and universal parts that among platform. The authors discuss the modular design role and the different between integral design, promote the method and the step of modular design, so change the low cost parts design, and give an new product based on the platform. Based on this model, they not only save the cost of develop new product, but also save time, achieve advantage which Mass produce process.     

Blade kinematic theory for rotary vane compressor

The advantage of blade-offset rotary vane compressor is analyzed, and its kinematic model is established through simplifying the vane motion to the circle center movement of the main vane arc by using equidistant curve envelope principle. Then, the relationship between the displacement, velocity, acceleration of blade and the angle of rotor is obtained. Finally, based on the theory obtained, the simulation is also carried out. Results show this method can avoid complex process for finding the contact point, which meanwhile has good solving accuracy. Because of the differences on kinematic characteristics, the blade kinematic analysis for blade-cardiac cannot be simply used for the blade-offset one, and the kinematic and dynamic characteristics of cylinder profile cannot be shown by the simplified analysis. However, the scientific theory calculation method for the kinematic analysis of blade-offset rotary vane compressor put forward provides a reliable theoretical basis for the innovation of multi-stage combination cylinder profile with high volumetric efficiency and compression ratio, and also broadens the design theory of the rotary vane compressor.     

Solid Model Design on the Features of Products

To research the problem of plastic art design and emulation of products with the virtual reality technology can short the product development cycle and reduce the cost. This paper discusses the information based on the product feature ,solid model with parameters, the structure and function of this system. Combined the product properties with its solid model. Proposed a method with CAD to create the model of the product based on features in the product design. Expressed its feature parameter and shape of model fully .In the case for a deceleration box the feature model has solved the problem of physical information ,geometry information and the informative process in its production management system efficiently.     

Performance simulation of high-power wind turbine under the action of wind and wave

In order to research the offshore wind turbine which operates in harsh environment with transient and variable working conditions, the system is simulated and analyzed by simulation technology. The aerodynamic load of wind turbine is calculated by applying GDW theory and wave load is calculated by applying Airy wave theory. The drive chain is programmed in Matlab/ simulink and the flexible multi-body model of the wind turbine is built in Adams. The combined simulation of the wind turbine is carried out. The results of a 5 MW offshore wind turbine show that the method has excellent ability to simulate the performance almost the same as software Bladed result.     

基于自动化的速冻荠菜馅加工工艺

自动化程度低、劳动强度大、生产效率低下、水资源浪费严重、加工成本高是荠菜传统速冻加工工艺存在的不足。研发的基于自动化的速冻荠菜馅加工工艺具有自动化程度增强、劳动力使用减少、水资源节约利用、清洗贯穿全过程、产品合格率和原料利用率提高等六大特点,确保了产品质量。     

Great Capacity of Data Logger Based on Virtual Instrument Technology

The Data Logger is an important secondary-instrument,which can be applied to automatic monitor and control system,and high speed local data acquisition for later analysis.The Virtual Great Capacity of Data Logger based on virtual instrument technology is a new instrument which has more advantages than the traditional Data Logger.The design method has been introduced from three ways,which includes system principle, hardware configuration and programming design, and an application example is given.This Data Logger is low cost,easy to take,also easy to operate.It can be widely used in many of actual applications.     

Computer Aided Analysis Tool for Building Energy Efficiency in Conceptual Design Stage

Conceptual design is one of the most important stages in building design, and energy efficiency analysis is one of the key issues in building conceptual design stage. The existing energy efficiency analysis methods and tools require inputing large number of parameters. However, the detail information of most parameters is not identified at the stage of conceptual design. And the current prevailing energy consumption simulation methods and tools are not appropriate at the stage of conceptual design. The proposed method can be used to compare the energy efficiency of multi strategies at the conceptual design phase. Minimum data were required to be input for achieving the optimal building design scheme. The method can provide a solution to the gap between the rapid building design cycle and the sustainable development demand in China.     

Building Energy Efficiency Design Procedure Based on Digital Technology

Abstract:Digital design technology is crucial for building energy efficiency design, while the key of building energy efficiency design is to analyze the entire design process, dynamic balance and energy cost. Through the application of digital technology in architectural design during its earlier phases, we can analyze such factors as local climate and terrain, create a "virtual building", simulate its actual condition, and conduct a scientific quantitative analysis of the key problems in architectural design. These actions will optimize the proposed design in a timely manner and achieve energy efficient design under the guidance of scientific analysis. Meanwhile, by exploring energy efficiency design procedure based on digital technology, we can adapt to a higher standard of energy efficient design in our new times.     

虚拟物流在国际配送中的应用研究

为了有效整合社会闲散的物流资源,提高企业的国际竞争力,实现高速、安全、低成本的虚拟国际配送,运用SWOT分析法论证了虚拟物流应用于国际配送的可行性,并系统的描述了虚拟国际配送中心的运作模式、业务流程、组织结构设计和运作流程,最后提出从企业和政府两个方面来构建虚拟物流应用于国际配送中的保障措施。     

Vibration Analysis and System Simulation for a Stalled Wind Turbine

The aerodynamic characteristic of wind turbine is calculated by applying the Blade Element Momentum(BEM) theory.Also finite element mode analysis is done for the tower and the rotor.Then the multi-dynamic model of the wind turbine is built in Adams.Also the drive chain is calculated by applying state space method and programmed in Matlab/ Simulink.With that the combined simulation of vibration characteristics is carried out on the base of MATLAB/Simulink and ADAMS,in which the transmission effects and aero-elasticity coupling is fully considered.The results show that the method is able to simulate the vibration characteristic almost the same as software Bladed,which is well-known for analyzing performance and loads for the design and certification of wind turbines.     

Key Techniques for Design and Manufacture of Micro Gas Turbine Engine

The characteristics of flow and combustion in micro gas turbine engine with the low Reynolds number and the high Mach number, the high Couette number and the low Biot number, as well as the ultra high duty ratio of combustion in very small space are analyzed, which are remarkably distinguished from those on macro scale. At the meantime, the limitation of traditional dynamic lubrication theory at ultra high speed on micro scale is presented, and the possibility of making the gas bearing to be able to work at ultra high speed by utilizing boundary slip is investigated. Due to the applied prospect of silicon carbide in the field of MEMS especially under high temperature and high strength conditions, the technical process of combining silicon etching with reactive sintering and grinding machining of silicon carbide is put forward so that the miniature machining of silicon carbide for micro gas turbine engine becomes possible.     

Progress in the Research of Titanium Sponge Processes

Titanium has many desirable properties (high specific strength and high corrosion-resistance). Titanium metal is a sort of product with promising market. Hunter process disappeared completely in 1993. The most widespread titanium sponge process is Kroll process (magnesium reduction). Its shortcomings (complicated route, high cost and serious pollution) are obvious although it is the most mature technology. The most advanced came up in UK, 1998. It is characterized by low cost, excellent product, short route and extensive adaptability, and is a type of high cleanness process. Compared with other processes, this electrolyzing process for the direct reduction of TiO 2 represents the tendency of titanium metal making in the future, and should be applicable to a wide range of metal oxides.     

用于齿面扭曲消减的齿向修形曲线设计方法

针对蜗杆砂轮磨消减齿面扭曲时存在成本高、效率低等问题,探讨在设计阶段消减齿面扭曲的途径。首先,基于蜗杆砂轮磨齿时的接触迹分析,给出了一种齿面扭曲的计算方法,分析了鼓形量及螺旋角对扭曲量的影响;其次,提出一种常用鼓形齿修形曲线的改进设计方法,将修形曲线分成三段,分别计算齿向左右两段各处扭曲量。在满足齿轮设计要求的前提下,通过调整三段曲线的比例因子以及各处的鼓形量,实现齿面扭曲量的消减。计算实例表明,该方法可有效消减齿面扭曲现象,减小齿向修形误差。     

水稻叶曲线特征的机理模型

通过对水稻叶片的受力分析，推导了叶曲线方程，并进行了影响系数的参数化和方程求解。对叶曲线方程的灵敏度分析表明，方程较好地体现了叶长、叶宽、叶形、比叶重和叶片形变系数等参数对叶曲线的综合影响，与生产中水稻株型特征变化相一致。进一步利用三维数字化仪获得的不同品种类型水稻拔节期和孕穗期叶脉空间坐标试验数据对叶曲线方程进行了模拟分析，结果表明叶曲线方程可以合理而可靠地定量描述水稻叶曲线特征的动态变化规律。     

“虚拟仿真工学结合”教学模式的探究

"虚拟仿真工学结合"教学模式是有效进行"工学结合"人才培养模式的一种教学模式。它是运用虚拟仿真技术,创设反映企业的真实生产环境和生产过程情境,实现专业学习与职业岗位技能对接,学习活动与生产实践有机融合;在虚拟现实中,使学习与工作、课堂与车间、理论与实践有效地结合起来,完成与岗位技能标准相对应的教学目标和内容,满足社会经济发展对人才培训的要求。     

The Analysis on the Effect of Cold and Heat Fluid Inlet Temperatures on the Thermodynamic Performance of Heat Exchanger

Based on the exergy analysis method,the thermodynamic performance of high and low temperature heat exchangers is analysed and the calculating expressions of exergy efficiency are given,which can be used to study systematically the effect of cold and heat fluid inlet temperatures on the exergy efficiency of the high and low temperature heat exchangers on the condition of considering pressure exergy loss and not.     

Product ontology screening and its application in variant design

A product ontology screening method which can be used in variant design is proposed. With the support of complete ontology view of product resources, the product functional requirement and structural characteristics are converted to demand constraints, which are used to screen product ontology. For different screening hierarchies and objects, different screening rules such as pattern matching, case matching combined with manual decision and auto matching on the basis of case-based reasoning are adopted. The semi-automatic screening method with human-computer cooperation has impressive effectiveness on the improvements of the accuracy of design schemes and the flexibility and efficiency of design process. Finally, a variant design supporting system for building door and window is developed, which proves the feasibility and effectiveness of the method.