Aerodynamic/stealth design of S-duct inlet based on discrete adjoint method

It is a major challenge for the airframe-inlet design of modern combat aircrafts,as the flow and electromagnetic wave propagation in the inlet of stealth aircraft are very complex.In this study,an aerodynamic/stealth optimization design method for an S-duct inlet is proposed.The upwind scheme is introduced to the aerodynamic adjoint equation to resolve the shock wave and flow separation.The multilevel fast multipole algorithm(MLFMA)is utilized for the stealth adjoint equation.A dorsal S-duct inlet of flying wing layout is optimized to improve the aerodynamic and stealth characteristics.Both the aerodynamic and stealth characteristics of the inlet are effectively improved.Finally,the optimization results are analyzed,and it shows that the main contradiction between aerodynamic characteristics and stealth characteristics is the centerline and crosssectional area.The S-duct is smoothed,and the cross-sectional area is increased to improve the aerodynamic characteristics,while it is completely opposite for the stealth design.The radar cross section(RCS)is reduced by phase cancelation for low frequency conditions.The method is suitable for the aerodynamic/stealth design of the aircraft airframe-inlet system.

XML-based Framework of Parametric Design for Typical Parts

Parametric design of typical parts holds a very important position during process of product designs. In order to develop a parametric design system of typical parts compatible with heterogeneous CAD systems, this paper presents a framework of a network-oriented design system of typical parts, enabled by eXtensible Markup Language (XML), capable of providing parametric design. Firstly, an overview of the framework is presented. In order to map the part feature hierarchy tree of 3D model into an XML tree, an XML-based part template is introduced. The methods of XML-based parametric design and parametric design navigation are described. Finally, an application example of prototype system under the Pro/Engineer platform is given. The application indicates that the proposed framework is valid for parametric design of typical parts/components in heterogeneous CAD systems.

A FEATURE－BASED PRODUCT MODELLING SYSTEM ON PC （CASE STUDY OF PARTS DESIGN FOR PRESS MACHINE）

This article reports on the design and implementation of feature modelling system for the CAPP of rotational symmetric components. The work deals with design by features, feature parts database design, and parts information modelling techniques realized in Personal Computer. The modular software provides utilities such as interactive component synthesis, dimensioning, tolerancing and graphical display.

Design scheme for fast charging station for electric vehicles with distributed photovoltaic power generation

The demand for fast charging is increasing owing to the rapid expansion of the market for electric vehicles. In addition, the power generation technology for distributed photovoltaic has matured. This paper presents a design scheme for a fast charging station for electric vehicles equipped with distributed photovoltaic power generation system taking the area with certain conditions in Beijing as an example construction site. The technical indexes and equipment lectotype covering the general framework and subsystems of the charging station are determined by analyzing the charging service demand of fast charging stations. In this study, the layout of the station is developed and the operation benefits of the station is analyzed. The design scheme realizes the design objective of "rationalization, modularization and intelligentization" of the fast charging station and can be used as reference for the construction of a fast charging network in urban area.

RHOMBUS THINKING METHOD AND ITS APPLICATION IN SCHEME DESIGN

Rhombus thinking, a new creative thinking method,is the combination of divergent thinking process and convergent thinking process,in which qualitative analysis is carried out before quantitative analysis This method tries to solve the bottle neck problem in intelligent CAD based on the extension theory The rhombus thinking method to the scheme design of new products is applied In this process, firstly, the matter element expression for the know information are set up, and then a set of matter elements are opened up by matter elements extension method; Finally,the useful information are got by appraisal method of dependent degree It has been successfully applied to the scheme design for the cutter store of machining center Theoretical and experimental results demonstrated fhat the method is much more accurate,objective and efficient than the traditional one

基于NAPA Designer的钻台结构参数化设计

钻台作为钻井船或钻井平台中钻井模块的载体,既要满足作业功能的需求,又受到主船体尺度和重量控制等因素的制约,故在初步设计阶段需快速制定不同设计方案供比较选择。在此背景下,该文基于NAPA Designer软件提供的二次开发功能,编写了钻台结构参数化设计模块,通过用户自定义界面数据交互驱动钻台参数化模型的创建和更新,可实现快速提供多种设计方案进行比选,并导出三维有限元模型用于结构强度的分析校核,从而得到钻台结构的优化设计方案。经过实船项目测试表明,基于NAPA Designer软件的钻台结构参数化设计方法可有效降低使用者门槛并显著提高设计效率。

Design of Ningdu Talent Apartment Design in Jiangxi

Taking the design of Ningdu Talent Apartment for example,active eco-design at the origin of design—design of building scheme was elaborated,including overall layout,planar design,eco-interface design,building environment and outer space design,sun-shading design.Implementation of ecological and energysaving concepts in building scheme was reviewed.

Self-organized evolution of mechanism kinetic scheme based on axiomatic design

The self-organized evolution technology of the mechanism kinetic scheme based on axiomatic design is presented. This technology tries to express the constraints between kinetic mechanisms briefly in a semantic form which is more familiar to the designers. Through the mapping process between the kinetic chain unit and the unit instance, the evolution from abstract unit to concrete engineering instance is achieved. The subdivision of unit coupling semantics is studied, and the evolution of semantics is finished. Also, the semantic constraints evolution of unit coupling semantics is described. The product structure models with function and assembly meanings are constructed based on the kinematic chain unit and unit coupling. It provides a basis to realize the inheritance and transfer of constraint information from conceptual design to design for assembly （DFA）. As the engineering practice result shows, the method can help the engineers express their And the automation, recursion and design intension more clearly and naturally in a high semantic level. visualization of the mechanism kinetic scheme design are realized

DESIGN TECHNOLOGY FOR INJECTION MOLD PARTING SURFACE BASED ON CASES AND KNOWLEDGE

On the basis of the comprehensive analysis about the automatic generation of the injection mold parting surface, the parting surface design method which introduces knowledge and case-based reasoning （CBR） into the computer-aided design is described by combining with the actual characteristic in injection mold design, and the design process of case-based reasoning method is also given. A case library including the information of parting surface is built with the index of main shape features, The automatic design of the mold parting surface is realized combined with the forward-reasoning method and the similarity solution procedure. The rule knowledge library is also founded including the knowledge, principles and experiences for parting surface design. An example is used to show the validity of the method, and the quality and the efficiency of the mold design are improved.

The Research on CAD/CAPP Integrated System for Welding Boxlike Parts Made of Plate

By adopting the parameterized designing method of f ea ture assembled and feature unit, for the feature of non-conventional type parts , such as welding box and bearer, by use of Visual C++ and AutoCAD a s soft tools, the system can successfully carry out the basic function of featur e assembled, the processing of two-dimensional figure, the building of three-d imensional feature, the automatic producing of technical papers, and so on. The thoughts and design methods of this system can be served as the preference to CA D/CAPP integrated for othernon-conventional type parts. For non-conventional parts, its feature is too much, so the parameter is much. By adopting interactive entry for graphic parameter, under the control of main c ontrol module, through inputting the feature parameter and calling the feature g raphic unit, the function for modeling is completed. To reduce input of feature parameter, the description of position feature is adopted in the feature descrip tion of non-conventional parts, that is, fix position is constraint through str ucture and dimension of non-conventional parts. In such a manner, the assembled process has been transformed the coordinate conversion process, and this is ver y important in the production of three-dimensional graphics. In the one hand, b y calling the feature of parts in the library of feature-graphic unit, the two -dimensional DXF file and three-dimensional SCR file are automatically produce d in AutoCAD. On the other hand, by calling the rules and standard operational s equences in the technologic knowledge base, through inferring of inference engin e, the assembled sequence of non-conventional parts and welding sequences are a utomatically produced. The two aspects constitute overall design philosophy for system. So the CAD/CAPP integration of feature-assembled for non-conventio nal parts are completed. The principle of dividing feature is based on the thought of group technology, t hat is, according to the function feature of parts. The feature-assembled p arameterized design method is to divide the parts into many feature-units, acco rding to the structure, function, and secondary feature, and the each unit is in teractively produced, so the whole part is assembled gradually. At the same time , to display the sequences which deviser chooses varied features, hidden feature code is adopted. The feature-unit parameterized design method is to assemble dimension, margin tolerance and fitting-in, and surface roughness into one unit that it becomes a fixed structure. However big it is, it could be added to or taken off like a ba sic feature-unit.By adopting above-mentioned methods, the module of parts is e stablished. Under the integrated environment, according to basic construct of expert system, CAPP system is made up of three sectionsdynamic database (document-view ), knowledge library and inference engine. Dynamic database is served as storing initialized and middle information as well as ultimate design result. The knowl edge library is composed of static database, rule set, and standard welding proc ess library.

A New D-optimal Design Scheme for the Identification of Cubic Polynomials

In this paper, the limitations of the single cube D-optimal design scheme is studied, and a double cube D-optimal design scheme is suggested in order to overcome the limitations. For a sort of incomplete cubic polynomials, the test design of the identification is developed with this new scheme, and the comparation with the single cube scheme is also given. This scheme is shown to be perfectly suitable for the optimal identification of the complete cubic polynomials.

Design strategy of intelligent CAD for welding positioner scheme design

Traditional CAD technique does not support the design processes such as function definition, conceptual design and preliminary design, which are most creative and play significant roles on the design quality. Because scheme design has close relationship with product structure, performance and technology cost, it is important for applying the intelligent CAD of scheme design to improve the quality and competitive level of the product. The definition and function of welding positioner are discussed in this paper. The new definition of welding positioner extends the research scope of welding positioner to welding fixture and welding positioning motion mechanism. The design process of welding fixture and positioning motion system is described, and the cased based and knowledge based design strategy of welding positioner scheme design intelligent CAD is then put forward, which lays foundation for developing proto type system of welding positioner scheme design.

U-Type Designs via New Generalized Partially Balanced Incomplete Block Designs with <i>m</i>= 4, 5 and 7 Associated Classes

The traditional combinatorial designs can be used as basic designs for constructing designs of computer experiments which have been used successfully till now in various domains such as engineering, pharmaceutical industry, etc. In this paper, a new series of generalized partially balanced incomplete blocks PBIB designs with m associated classes (m = 4, 5 and 7) based on new generalized association schemes with number of treatments v arranged in w arrays of n rows and l columns (w ≥ 2, n ≥ 2, l ≥ 2) is defined. Some construction methods of these new PBIB are given and their parameters are specified using the Combinatory Method (s). For n or l even and s divisor of n or l, the obtained PBIB designs are resolvable PBIB designs. So the Fang RBIBD method is applied to obtain a series of particular U-type designs U (wnl;) (r is the repetition number of each treatment in our resolvable PBIB design).

Optimal Selection Model of Equipment Design Scheme Based on Set Pair Analysis

Selecting the optimal one from similar schemes is a paramount work in equipment design.In consideration of similarity of schemes and repetition of characteristic indices,the theory of set pair analysis(SPA)is proposed,and then an optimal selection model is established.In order to improve the accuracy and flexibility,the model is modified by the contribution degree.At last,this model has been validated by an example,and the result demonstrates the method is feasible and valuable for practical usage.

Design Scheme of Electric Lifting Workbench for Maintenance of Aerometer in Observation Field

The wind speed and wind direction meter of meteorological station is installed on the wind meter pole 10 meters high from the observation site, which also causes some difficulties for the maintenance of the wind speed and wind direction meter in the later period. Based on this situation, an electric lifting worktable (referred to as the electric lifting worktable) is specially designed for the maintenance of wind meters in meteorological observation sites. It can lift the maintenance personnel and equipment and tools to a height convenient for work, and then grasp the wind meter pole through the mechanical arm. It can be operated by a single person, thus getting rid of the traditional dimension by climbing the wind meter pole or releasing the wind meter pole. The present situation of repairing has the characteristics of saving manpower and easy operation, which is conducive to improving work efficiency and reducing work intensity. It also greatly guarantees the safety of maintenance personnel, and has good practicability and extensive popularization value.

Secret Sharing Schemes Based on the Dual Code of the Code of a Symmetric （v, k, λ）-Design and Minimal Access Sets

Secret sharing has been a subject of study for over 30 years. The coding theory has been an important role in the constructing of the secret sharing schemes. It is known that every linear code can be used to construct the secret sharing schemes. Since the code of a symmetric （V, k, λ）-design is a linear code, this study is about the secret sharing schemes based on C of Fp-code C of asymmetric （v, k, λ）-design.

Tight Relative 6-designs on Binary Hamming Association Schemes

The concept of relative t-designs for Q-polynomial association schemes is due to Delsarte(Philips Res Rep 32: 373C411, 1997). In this paper, we discuss the Fisher type lower bounds of tight relative 6-designs very explicitly for binary Hamming association schemes H(n, 2).

An Approach to Representation for Principle Scheme Design

One of the open issues in principle scheme design of mechanical systems is principle representation, which not only outlines the physical principles, but also facilitates the design synthesis. An energy-based approach to represent principle scheme design is proposed. Firstly, an energy interaction model of mechanical systems is established and an intermediate model is derived, in which principle scheme design is transformed into solving the energy functions of system. Then the energy functions are modeled with the language of bond graphs, and principle representation for components is presented. Finally, characteristics of the developed representation approach are analyzed and a design example of gate drive system is given to demonstrate this approach.

Design and Analysis of Test Schemes of Static Postponing Time on Shrapnels Used to Riot Control

The test scheme of static postponing time given in our actual national military test standard on shrapnels used to control riot is a nine-point test scheme on the combined action of three kinds of temperatures and three kinds of pressures, the consumed ammunitions are more excessive. Statistic analysis and tentative checkout about a lot of test data are done, feasibility gists are put forward for optimizing of the test design scheme. The optimizing design and data analysis of test scheme of the item are done by managing uniformity design theory, two scientific and reasonable six-point test schemes are confirmed. The feasibility and reliability of the optimizing design schemes put forward above are proved ulteriorly by test validating. The gained schemes not only have good design uniformity and little ammunition wastage and meet the test demand, but also have better forecast ability for the result data of other points using the mathematic models from the actual test points.

Victory Ceremony Hosts/Hostess Costume Design Scheme for Beijing Olympics Sought

The Beijing Organizing Committee for the Games of the 29th Olympiad(BOCOG)announced on May 22 that it is organizing a bid across the nation for the design scheme of the victory ceremony hosts/hostess costumes for the Beijing 2008 Olympic Games from May 23 to June 25,2007.