This paper creates 3D solid model and assembly of U RJ 92-6 oil tank and analyses its strength by integrated CAD/CAE/CAM software I-D EAS. Through integrated simulation in computer, design efficiency and quality of oi...This paper creates 3D solid model and assembly of U RJ 92-6 oil tank and analyses its strength by integrated CAD/CAE/CAM software I-D EAS. Through integrated simulation in computer, design efficiency and quality of oil tank is greatly improved. Adopting integrated CAD/CAE/CAM software to carry out integrated research to equ ipment and products, we will be able to take overall analysis in aspects of 3-D solid modeling, pre-assembly and strength, etc., to realize non-paper designi ng and parallel designing. Problems can be found and settled during designing, w hich will increase designing efficiency and one-time success rate and realize o ptimum designing for products.展开更多
This study integrated instrumental and relational approaches to the teaching and learning of solids in a preservice teacher's class. The researcher guided the preservice teachers to gather various prisms, pyramids, a...This study integrated instrumental and relational approaches to the teaching and learning of solids in a preservice teacher's class. The researcher guided the preservice teachers to gather various prisms, pyramids, and spheres to study the total surface areas and volumes. At the end of the integrated models, the test scores showed closed relationships in the concurrent instructional strategies of the integrated models. The researcher therefore, recommended the design models for the teaching and learning of solids in mathematics.展开更多
The inner rotors of distributed propulsion tilt-wing Unmanned Aerial Vehicles(UAVs)are often folded in the cruising state and deployed in vertical take-off and landing to cope with the huge difference in thrust requir...The inner rotors of distributed propulsion tilt-wing Unmanned Aerial Vehicles(UAVs)are often folded in the cruising state and deployed in vertical take-off and landing to cope with the huge difference in thrust requirements.However,the blades of the conventional rotor have poor conformality with the nacelle profile,which will greatly increase the drag of the UAV after folding.This paper proposes an integrated method for the design of rotor and nacelle considering geometric compatibility to reduce the drag of the folded rotor and nacelle,so as to further improve the aerodynamic efficiency in cruise while ensuring the rotor efficiency in the vertical flight mode.A geometric mapping model based on nacelle design parameters and rotor design parameters is established,and a parametric model and aerodynamic optimization model of the outer arc airfoil family are developed.In addition,a rotor performance analysis model and a neural network response surface model for nacelle drag prediction that meet the requirements of confidence level are established.Based on the oblique inflow blade element momentum theory method,numerical simulation method,and genetic algorithm,an integrated optimization framework of the design of the conformal rotor and nacelle is built.Then,a geometrically compatible integrated optimization for the rotor and nacelle is carried out with the objective of maximizing energy efficiency in the full mission profile.Finally,a conformal rotor and nacelle design solution is obtained,which satisfies geometric compatibility and thrust constraints while providing high thrust efficiency and low cruising drag.A comparison of the results of the integrated design and the conventional rotor optimization design shows that the drag of the conventional rotor is 3.45 times that of the conformal integrated design in the cruising state,which proves the effectiveness and necessity of the proposed method.展开更多
According to the variable toe-to-heel well spacing, combined with the dislocation theory, discrete lattice method, and finite-element-method(FEM) based fluid-solid coupling, an integrated geological-engineering method...According to the variable toe-to-heel well spacing, combined with the dislocation theory, discrete lattice method, and finite-element-method(FEM) based fluid-solid coupling, an integrated geological-engineering method of volume fracturing for fan-shaped well pattern is proposed considering the geomechanical modeling, induced stress calculation, hydraulic fracturing simulation, and post-frac productivity evaluation. Besides, we propose the differential fracturing design for the conventional productivity-area and the potential production area for fan-shaped horizontal wells. After the fracturing of the conventional production area for H1 fan-shaped well platform, the research shows that the maximum reduction of the horizontal principal stress difference in the potential productivity-area is 0.2 MPa, which cannot cause the stress reversal, but this reduction is still conducive to the lateral propagation of hydraulic fractures. According to the optimized fracturing design, in zone-Ⅰ of the potential production area, only Well 2 is fractured, with a cluster spacing of 30 m and an injection rate of 12 m^(3)/min per stage;in zone-Ⅱ, Well 2 is fractured before Well 3, with a cluster spacing of 30 m and an injection rate of 12 m^(3)/min per stage. The swept area of the pore pressure drop in the potential production area is small, showing that the reservoir is not well developed. The hydraulic fracturing in the toe area can be improved by, for example, properly densifying the fractures and adjusting the fracture distribution, in order to enhance the swept volume and increase the reservoir utilization.展开更多
In order to achieve holistic urban plans incorporating transport infrastructure,public space and the behavior of people in these spaces,integration of urban design and computer modeling is a promising way to provide b...In order to achieve holistic urban plans incorporating transport infrastructure,public space and the behavior of people in these spaces,integration of urban design and computer modeling is a promising way to provide both qualitative and quantitative support to decisionmakers.This paper describes a systematic literature review following a four-part framework.Firstly,to understand the relationship of elements of transport,spaces,and humans,w e review policy and urban design strategies for promoting positive interactions.Secondly,we present an overview of the integration methods and strategies used in urban design and policy discourses.Afterward,metrics and approaches for evaluating the effectiveness of integrated plan alternatives are reviewed.Finally,this paper gives a review of state-of-the-art tools with a focus on seven com puter simulation paradigms.This article explores mechanisms underlying the complex system of transport,spaces,and humans from a multidisciplinary perspective to provide an integrated toolkit for designers,planners,modelers and decision-m akers with the current methods and their challenges.展开更多
According to the operational characteristics of the logistics networks for the third party logistics supplier (3PLS), the forward and reverse logistics networks together for 3PLS under the uncertain environment are ...According to the operational characteristics of the logistics networks for the third party logistics supplier (3PLS), the forward and reverse logistics networks together for 3PLS under the uncertain environment are designed. First, a fuzzy model is proposed by taking multiple customers, multiple commodities, capacitated facility location and integrated logistics facility layout into account. In the model, the fuzzy customer demands and transportation rates are illustrated by triangular fuzzy numbers. Secondly, the fuzzy model is converted into a crisp model by applying fuzzy chance constrained theory and possibility theory, and one hybrid genetic algorithm is designed for the crisp model. Finally, two different examples are designed to illustrate that the model and solution discussed are valid.展开更多
In the design process of advanced aero-engines,it is necessary to carry out an effective analysis method between structural features and mechanical characteristics for a better structural optimization.Based on the str...In the design process of advanced aero-engines,it is necessary to carry out an effective analysis method between structural features and mechanical characteristics for a better structural optimization.Based on the structural composition and functions of aero-engines,the concept and contents of structural efficiency can reflect the relation between structural features and mechanical characteristics.In order to achieve the integrated design of structural and mechanical characteristics,one quantitative analysis method called Structural Efficiency Assessment Method(SEAM)was put forward.The structural efficiency coefficient was obtained by synthesizing the parameters to quantitatively evaluate the aero-engine structure design level.Parameterization method to evaluate structural design quality was realized.After analyzing the structural features of an actual dual-rotor system in typical high bypass ratio turbofan engines,the mechanical characteristics and structural efficiency coefficient were calculated.Structural efficiency coefficient of high-pressure rotor(0.43)is higher than that of low-pressure rotor(0.29),which directly shows the performance of the former is better,there is room for improvement in structural design of the low-pressure rotor.Thus the direction of structural optimization was pointed out.The applications of SEAM shows that the method is operational and effective in the evaluation and improvement of structural design.展开更多
Design is a goal-oriented planning activity for creating products,processes,and systems with desired functions through specifications.It is a decision-making exploration:the design outcome may vary greatly depending o...Design is a goal-oriented planning activity for creating products,processes,and systems with desired functions through specifications.It is a decision-making exploration:the design outcome may vary greatly depending on the designer’s knowledge and philosophy.Integrated design is one type of design philosophy that takes an interdisciplinary and holistic approach.In civil engineering,structural design is such an activity for creating buildings and infrastructures.Recently,structural design in many countries has emphasized a performance-based philosophy that simultaneously considers a structure’s safety,durability,serviceability,and sustainability.Consequently,integrated design in civil engineering has become more popular,useful,and important.Material-oriented integrated design and construction of structures(MIDCS)combine materials engineering and structural engineering in the design stage:it fully utilizes the strengths of materials by selecting the most suitable structural forms and construction methodologies.This paper will explore real-world examples of MIDCS,including the realization of MIDCS in timber seismic-resistant structures,masonry arch structures,long-span steel bridges,prefabricated/on-site extruded light-weight steel structures,fiber-reinforced cementitious composites structures,and fiber-reinforced polymer bridge decks.Additionally,advanced material design methods such as bioinspired design and structure construction technology of additive manufacturing are briefly reviewed and discussed to demonstrate how MIDCS can combine materials and structures.A unified strengthdurability design theory is also introduced,which is a human-centric,interdisciplinary,and holistic approach to the description and development of any civil infrastructure and includes all processes directly involved in the life cycle of the infrastructure.Finally,this paper lays out future research directions for further development in the field.展开更多
The research on scroll profiles theory at present mainly is aiming at the single profile and its amelioration or parameter optimization,not aiming at the natural characteristic of the profiles equation of scroll profi...The research on scroll profiles theory at present mainly is aiming at the single profile and its amelioration or parameter optimization,not aiming at the natural characteristic of the profiles equation of scroll profiles itself.Thus,the intrinsic differential equation bearing on arc-length and tangent direction angle was studied.Using the inherent differential equation and general functional theory,the conversion ideas between the expression of intrinsic differential equation and the expression in Cartesian coordinate was studied,and the condition of involutes characteristic was presented.The detailed analysis of four typical scroll profiles was given.According to the four typical scroll profiles and based on the method of Taylor series,the unified formation of general functional integration scroll profiles was established,which perfected general theory of scroll profiles increasingly.The envelope method to seek conjugation engagement profiles was studied.The unified general functional equation of scroll profiles represented the admissible function scrolls and the conjugation engagement characteristic of which was studied.The engagement condition of conjugation scroll profiles and the expression in Cartesian coordinate of conjugation scroll profiles of general functional integration scroll profiles were educed.Therefore,the restriction of inherent characteristics of single scroll profiles model is broken through.Solid modeling and machine tool path simulation can bridge the gap between design and manufacture which is essential for the design and manufacture of scroll compressors.With this method a perfect solid model can be achieved,which leads to an optimal design in terms of quality,delivery time and cost.The presentation of unified formation of general functional integration scroll profiles represents foundation factor of instinct characteristics of scroll profiles,which widens the design method of scroll compressor for automobile air conditioning.展开更多
In order to shorten aero-engine axial length,substituting the traditional long chord thick strut design accompanied with the traditional low pressure(LP) stage nozzle,LP turbine is integrated with intermediate turbine...In order to shorten aero-engine axial length,substituting the traditional long chord thick strut design accompanied with the traditional low pressure(LP) stage nozzle,LP turbine is integrated with intermediate turbine duct(ITD).In the current paper,five vanes of the first stage LP turbine nozzle is replaced with loaded struts for supporting the engine shaft,and providing oil pipes circumferentially which fulfilled the areo-engine structure requirement.However,their bulky geometric size represents a more effective obstacle to flow from high pressure(HP) turbine rotor.These five struts give obvious influence for not only the LP turbine nozzle but also the flowfield within the ITD,and hence cause higher loss.Numerical investigation has been undertaken to observe the influence of the Nozzle-Strut integrated design concept on the flowfield within the ITD and the nearby nozzle blades.According to the computational results,three main conclusions are finally obtained.Firstly,a noticeable low speed area is formed near the strut's leading edge,which is no doubt caused by the potential flow effects.Secondly,more severe radial migration of boundary layer flow adjacent to the strut's pressure side have been found near the nozzle's trailing edge.Such boundary layer migration is obvious,especially close to the shroud domain.Meanwhile,radial pressure gradient aggravates this phenomenon.Thirdly,velocity distribution along the strut's pressure side on nozzle's suction surface differs,which means loading variation of the nozzle.And it will no doubt cause nonuniform flowfield faced by the downstream rotor blade.展开更多
Hypersonic vehicles(HSVs)exhibit significant advantages over other vehicles,including the wide range of velocity and large airspace types,and these features have contributed to the rapid development of HSVs in the las...Hypersonic vehicles(HSVs)exhibit significant advantages over other vehicles,including the wide range of velocity and large airspace types,and these features have contributed to the rapid development of HSVs in the last 20 years.Moreover,hypersonic technologies have become a multidisciplinary research topic in the fields of aerodynamics,propulsion,structure,material,and control.Different types of re-entry gliding,air-breathing cruise,and aerospace vehicles have been designed to realize ambitious tasks,which in turn influenced the technological advancements and process change in the military.This paper summarizes the control-oriented integrated design of HSVs.First,the status of current research on the distinct characteristics and technique issues of HSVs is introduced.Then,the progresses made on complex modeling,guidance and control,and trajectory optimization are elaborated to exhibit the significant research interest in hypersonic technologies.The control-integrated design of HSVs is emphasized to solve the multidisciplinary design problems associated with the model and its control and trajectory.Various strategies regarding the multidisciplinary optimization design are also proposed to solve the integrated design problem.Finally,suggestions are provided for the control-oriented integrated design of HSVs.展开更多
The purpose of this study is to contribute methodologically, through a systematic study of the application of different optimization techniques to design integrated distillation columns in binary, for it established o...The purpose of this study is to contribute methodologically, through a systematic study of the application of different optimization techniques to design integrated distillation columns in binary, for it established one optimization technique, deterministic, was optimized distillation column at steady state. For this part was used tabu search to solve the type binary problem. For each choice of the search whole continuous variables were optimized with the deterministic method for process design perturbation is applied to the molar fraction of the feed. It develops and implements the mathematical algorithm solving the problem, then validation of the methodology proposed dynamic simulation of the system is compared with and without control, with both traditional and integrated approaches.展开更多
A CAD tools environment is described to support concurrent collaborative design. The environment has four components: shared design representation, design process control, CAD tools, designer interface. So...A CAD tools environment is described to support concurrent collaborative design. The environment has four components: shared design representation, design process control, CAD tools, designer interface. Some related issues for the construction, such as form feature handling, constraint satisfaction, design process control, STEP based information integration, are discussed in more detail.展开更多
The integrated layout problem in manufacturing Systems is investigated. Anintegrated model for Concurrent layout design of cells and flow paths is formulated. A hybridapproach combined an enhanced branch-and-bound alg...The integrated layout problem in manufacturing Systems is investigated. Anintegrated model for Concurrent layout design of cells and flow paths is formulated. A hybridapproach combined an enhanced branch-and-bound algorithm with a simulated annealing scheme isproposed to solve this problem. The integrated layout method is applied to re-layout the gear pumpshop of a medium-size manufacturer of hydraulic pieces. Results show that the proposed layout methodcan concurrently provide good solutions of the cell layouts and the flow path layouts.展开更多
An analytical model for current-voltage behavior of amorphous In-Ga-Zn-O thin-film transistors(a-IGZO TFTs)with dual-gate structures is developed.The unified expressions for synchronous and asynchronous operating mo...An analytical model for current-voltage behavior of amorphous In-Ga-Zn-O thin-film transistors(a-IGZO TFTs)with dual-gate structures is developed.The unified expressions for synchronous and asynchronous operating modes are derived on the basis of channel charges,which are controlled by gate voltage.It is proven that the threshold voltage of asynchronous dual-gate IGZO TFTs is adjusted in proportion to the ratio of top insulating capacitance to the bottom insulating capacitance(C_(TI)/C_(BI)).Incorporating the proposed model with Verilog-A,a touch-sensing circuit using dual-gate structure is investigated by SPICE simulations.Comparison shows that the touch sensitivity is increased by the dual-gate IGZO TFT structure.展开更多
Die casting process is one of the prime options for m anufacturing precisely dimensioned, sharply defined metal parts. The design of d ie casting dies comprises several stages and entails a large amount of time. Tra d...Die casting process is one of the prime options for m anufacturing precisely dimensioned, sharply defined metal parts. The design of d ie casting dies comprises several stages and entails a large amount of time. Tra ditionally, the different stages of the die design were not integrated but exist as separate entities. Moreover, recurring modifications or even redesigns are r equired due to the complexity in achieving an accurate initial die design. As a result, die design is usually time-consuming and costly with respect to resourc es. The die casting industry will greatly benefit if proper application software are developed that integrates the different die design stages and allows editin g of die design as and when needed. Hence it is imperative to create an integrat ed die design system that shortens the die design time. This paper presents a research that establishes a prototype of an integrated die design system. It is developed using the commercial SolidWorks CAD system and n amed DiWorks. The aim of building the system on a commercial CAD system is to ut ilise the resources and features of the CAD system to speed up the die design pr ocess. DiWorks consists of six distinct modules: Project Manager, Cavity Insert Builder, Gating System Constructor, Die Base Designer, Ejector System Constructo r and Standard Components Library. Through these six modules, the die designer c an create a complete die casting die beginning from a product part model. It is a user-friendly system that allows both experienced and novice die designers to easily accomplish the task of die design. The practical goal of this research is twofold: to develop a system that integra tes the die design process and at the same time facilitates the editing of d ie design during or after the course of the design process. The research approac h includes (i) parametric design, (ii) feature-based design (iii) system modeli ng and implementation. Parametric design deals with variable dimensions as contr ol parameters, and it is an efficient tool for creating models based on paramete rs. Parametric design not only increases the design efficiency, but also makes t he updates and modifications of existing designs easier and faster, since these can be achieved by changing the parameters of the parametric model. Feature-bas ed design is used to design a product with features that are functionally define d by attributes and are geometrically represented by a set of parameters. The re sults of this research will aid the automation of the die design process, thus i mproving the efficiency and quality of, and reducing the cost of die design.展开更多
In this paper, sensitivity approaches are taken to analyze and design an integrated flight propulsion control system where the interaction between subsystems direitly affects the stability property and handling perfor...In this paper, sensitivity approaches are taken to analyze and design an integrated flight propulsion control system where the interaction between subsystems direitly affects the stability property and handling performances of the aircraft. The eigenvalue sen sitivity approach is employed to study the effect of coupling parameters on system stability and gain sensitivity approach is used to direct the reduced states feedback suboptimal control system design. Simulation results show that the integrated flight propulsion control system designed by sensitivity approaches is of good performance.展开更多
This paper describes how database information and electronic 3D models are integrated to produce power plant designs more efficiently and accurately. Engineering CAD/CAE systems have evolved from strictly 3D modeling ...This paper describes how database information and electronic 3D models are integrated to produce power plant designs more efficiently and accurately. Engineering CAD/CAE systems have evolved from strictly 3D modeling to spatial data management tools. This paper describes how process data, commodities, and location data are disseminated to the various project team members through a central integrated database. The database and 3D model also provide a cache of information that is valuable to the constructor, and operations and maintenance Personnel.展开更多
文摘This paper creates 3D solid model and assembly of U RJ 92-6 oil tank and analyses its strength by integrated CAD/CAE/CAM software I-D EAS. Through integrated simulation in computer, design efficiency and quality of oil tank is greatly improved. Adopting integrated CAD/CAE/CAM software to carry out integrated research to equ ipment and products, we will be able to take overall analysis in aspects of 3-D solid modeling, pre-assembly and strength, etc., to realize non-paper designi ng and parallel designing. Problems can be found and settled during designing, w hich will increase designing efficiency and one-time success rate and realize o ptimum designing for products.
文摘This study integrated instrumental and relational approaches to the teaching and learning of solids in a preservice teacher's class. The researcher guided the preservice teachers to gather various prisms, pyramids, and spheres to study the total surface areas and volumes. At the end of the integrated models, the test scores showed closed relationships in the concurrent instructional strategies of the integrated models. The researcher therefore, recommended the design models for the teaching and learning of solids in mathematics.
基金the Fundamental Research Funds for the Central Universities(No.56XCA2205402).
文摘The inner rotors of distributed propulsion tilt-wing Unmanned Aerial Vehicles(UAVs)are often folded in the cruising state and deployed in vertical take-off and landing to cope with the huge difference in thrust requirements.However,the blades of the conventional rotor have poor conformality with the nacelle profile,which will greatly increase the drag of the UAV after folding.This paper proposes an integrated method for the design of rotor and nacelle considering geometric compatibility to reduce the drag of the folded rotor and nacelle,so as to further improve the aerodynamic efficiency in cruise while ensuring the rotor efficiency in the vertical flight mode.A geometric mapping model based on nacelle design parameters and rotor design parameters is established,and a parametric model and aerodynamic optimization model of the outer arc airfoil family are developed.In addition,a rotor performance analysis model and a neural network response surface model for nacelle drag prediction that meet the requirements of confidence level are established.Based on the oblique inflow blade element momentum theory method,numerical simulation method,and genetic algorithm,an integrated optimization framework of the design of the conformal rotor and nacelle is built.Then,a geometrically compatible integrated optimization for the rotor and nacelle is carried out with the objective of maximizing energy efficiency in the full mission profile.Finally,a conformal rotor and nacelle design solution is obtained,which satisfies geometric compatibility and thrust constraints while providing high thrust efficiency and low cruising drag.A comparison of the results of the integrated design and the conventional rotor optimization design shows that the drag of the conventional rotor is 3.45 times that of the conformal integrated design in the cruising state,which proves the effectiveness and necessity of the proposed method.
基金Supported by National Natural Science Foundation of China (52104029,U2139204)PetroChina Science and Technology Innovation Foundation (2021 DQ02-0501)。
文摘According to the variable toe-to-heel well spacing, combined with the dislocation theory, discrete lattice method, and finite-element-method(FEM) based fluid-solid coupling, an integrated geological-engineering method of volume fracturing for fan-shaped well pattern is proposed considering the geomechanical modeling, induced stress calculation, hydraulic fracturing simulation, and post-frac productivity evaluation. Besides, we propose the differential fracturing design for the conventional productivity-area and the potential production area for fan-shaped horizontal wells. After the fracturing of the conventional production area for H1 fan-shaped well platform, the research shows that the maximum reduction of the horizontal principal stress difference in the potential productivity-area is 0.2 MPa, which cannot cause the stress reversal, but this reduction is still conducive to the lateral propagation of hydraulic fractures. According to the optimized fracturing design, in zone-Ⅰ of the potential production area, only Well 2 is fractured, with a cluster spacing of 30 m and an injection rate of 12 m^(3)/min per stage;in zone-Ⅱ, Well 2 is fractured before Well 3, with a cluster spacing of 30 m and an injection rate of 12 m^(3)/min per stage. The swept area of the pore pressure drop in the potential production area is small, showing that the reservoir is not well developed. The hydraulic fracturing in the toe area can be improved by, for example, properly densifying the fractures and adjusting the fracture distribution, in order to enhance the swept volume and increase the reservoir utilization.
文摘In order to achieve holistic urban plans incorporating transport infrastructure,public space and the behavior of people in these spaces,integration of urban design and computer modeling is a promising way to provide both qualitative and quantitative support to decisionmakers.This paper describes a systematic literature review following a four-part framework.Firstly,to understand the relationship of elements of transport,spaces,and humans,w e review policy and urban design strategies for promoting positive interactions.Secondly,we present an overview of the integration methods and strategies used in urban design and policy discourses.Afterward,metrics and approaches for evaluating the effectiveness of integrated plan alternatives are reviewed.Finally,this paper gives a review of state-of-the-art tools with a focus on seven com puter simulation paradigms.This article explores mechanisms underlying the complex system of transport,spaces,and humans from a multidisciplinary perspective to provide an integrated toolkit for designers,planners,modelers and decision-m akers with the current methods and their challenges.
文摘According to the operational characteristics of the logistics networks for the third party logistics supplier (3PLS), the forward and reverse logistics networks together for 3PLS under the uncertain environment are designed. First, a fuzzy model is proposed by taking multiple customers, multiple commodities, capacitated facility location and integrated logistics facility layout into account. In the model, the fuzzy customer demands and transportation rates are illustrated by triangular fuzzy numbers. Secondly, the fuzzy model is converted into a crisp model by applying fuzzy chance constrained theory and possibility theory, and one hybrid genetic algorithm is designed for the crisp model. Finally, two different examples are designed to illustrate that the model and solution discussed are valid.
基金AECC Commercial Aircraft Engine Co.,LTD for providing the financial support。
文摘In the design process of advanced aero-engines,it is necessary to carry out an effective analysis method between structural features and mechanical characteristics for a better structural optimization.Based on the structural composition and functions of aero-engines,the concept and contents of structural efficiency can reflect the relation between structural features and mechanical characteristics.In order to achieve the integrated design of structural and mechanical characteristics,one quantitative analysis method called Structural Efficiency Assessment Method(SEAM)was put forward.The structural efficiency coefficient was obtained by synthesizing the parameters to quantitatively evaluate the aero-engine structure design level.Parameterization method to evaluate structural design quality was realized.After analyzing the structural features of an actual dual-rotor system in typical high bypass ratio turbofan engines,the mechanical characteristics and structural efficiency coefficient were calculated.Structural efficiency coefficient of high-pressure rotor(0.43)is higher than that of low-pressure rotor(0.29),which directly shows the performance of the former is better,there is room for improvement in structural design of the low-pressure rotor.Thus the direction of structural optimization was pointed out.The applications of SEAM shows that the method is operational and effective in the evaluation and improvement of structural design.
基金This work was supported by the Science and Technology Development Fund,Macao SAR(0083/2018/A2)Multi-Year Research Grant(MYRG2019-00135-IAPME)Research&Development Grant for Chair Professor(CPG2020-00002-IAPME).
文摘Design is a goal-oriented planning activity for creating products,processes,and systems with desired functions through specifications.It is a decision-making exploration:the design outcome may vary greatly depending on the designer’s knowledge and philosophy.Integrated design is one type of design philosophy that takes an interdisciplinary and holistic approach.In civil engineering,structural design is such an activity for creating buildings and infrastructures.Recently,structural design in many countries has emphasized a performance-based philosophy that simultaneously considers a structure’s safety,durability,serviceability,and sustainability.Consequently,integrated design in civil engineering has become more popular,useful,and important.Material-oriented integrated design and construction of structures(MIDCS)combine materials engineering and structural engineering in the design stage:it fully utilizes the strengths of materials by selecting the most suitable structural forms and construction methodologies.This paper will explore real-world examples of MIDCS,including the realization of MIDCS in timber seismic-resistant structures,masonry arch structures,long-span steel bridges,prefabricated/on-site extruded light-weight steel structures,fiber-reinforced cementitious composites structures,and fiber-reinforced polymer bridge decks.Additionally,advanced material design methods such as bioinspired design and structure construction technology of additive manufacturing are briefly reviewed and discussed to demonstrate how MIDCS can combine materials and structures.A unified strengthdurability design theory is also introduced,which is a human-centric,interdisciplinary,and holistic approach to the description and development of any civil infrastructure and includes all processes directly involved in the life cycle of the infrastructure.Finally,this paper lays out future research directions for further development in the field.
基金supported by the National Natural Science Foundation of China (Grant No 50805149)China Postdoctoral Science Foundation (Grant No 20090450166/201003669)+2 种基金Chongqing Municipal Intellectual Property Office Special FoundationChongqing Science and Technology Commission Key Project Foundation (CSTC) (Grant No 2009AB3234)Chongqing University Innovation Group Team Project (Grant No KJTD201019)
文摘The research on scroll profiles theory at present mainly is aiming at the single profile and its amelioration or parameter optimization,not aiming at the natural characteristic of the profiles equation of scroll profiles itself.Thus,the intrinsic differential equation bearing on arc-length and tangent direction angle was studied.Using the inherent differential equation and general functional theory,the conversion ideas between the expression of intrinsic differential equation and the expression in Cartesian coordinate was studied,and the condition of involutes characteristic was presented.The detailed analysis of four typical scroll profiles was given.According to the four typical scroll profiles and based on the method of Taylor series,the unified formation of general functional integration scroll profiles was established,which perfected general theory of scroll profiles increasingly.The envelope method to seek conjugation engagement profiles was studied.The unified general functional equation of scroll profiles represented the admissible function scrolls and the conjugation engagement characteristic of which was studied.The engagement condition of conjugation scroll profiles and the expression in Cartesian coordinate of conjugation scroll profiles of general functional integration scroll profiles were educed.Therefore,the restriction of inherent characteristics of single scroll profiles model is broken through.Solid modeling and machine tool path simulation can bridge the gap between design and manufacture which is essential for the design and manufacture of scroll compressors.With this method a perfect solid model can be achieved,which leads to an optimal design in terms of quality,delivery time and cost.The presentation of unified formation of general functional integration scroll profiles represents foundation factor of instinct characteristics of scroll profiles,which widens the design method of scroll compressor for automobile air conditioning.
基金supported by grants from the National Natural Science Foundation of China(No.51306177)
文摘In order to shorten aero-engine axial length,substituting the traditional long chord thick strut design accompanied with the traditional low pressure(LP) stage nozzle,LP turbine is integrated with intermediate turbine duct(ITD).In the current paper,five vanes of the first stage LP turbine nozzle is replaced with loaded struts for supporting the engine shaft,and providing oil pipes circumferentially which fulfilled the areo-engine structure requirement.However,their bulky geometric size represents a more effective obstacle to flow from high pressure(HP) turbine rotor.These five struts give obvious influence for not only the LP turbine nozzle but also the flowfield within the ITD,and hence cause higher loss.Numerical investigation has been undertaken to observe the influence of the Nozzle-Strut integrated design concept on the flowfield within the ITD and the nearby nozzle blades.According to the computational results,three main conclusions are finally obtained.Firstly,a noticeable low speed area is formed near the strut's leading edge,which is no doubt caused by the potential flow effects.Secondly,more severe radial migration of boundary layer flow adjacent to the strut's pressure side have been found near the nozzle's trailing edge.Such boundary layer migration is obvious,especially close to the shroud domain.Meanwhile,radial pressure gradient aggravates this phenomenon.Thirdly,velocity distribution along the strut's pressure side on nozzle's suction surface differs,which means loading variation of the nozzle.And it will no doubt cause nonuniform flowfield faced by the downstream rotor blade.
基金Aerospace Science and Technology Innovation Fund(CASC2016)Six Talent Peaks Project in Jiangsu Province(KTHY-025).
文摘Hypersonic vehicles(HSVs)exhibit significant advantages over other vehicles,including the wide range of velocity and large airspace types,and these features have contributed to the rapid development of HSVs in the last 20 years.Moreover,hypersonic technologies have become a multidisciplinary research topic in the fields of aerodynamics,propulsion,structure,material,and control.Different types of re-entry gliding,air-breathing cruise,and aerospace vehicles have been designed to realize ambitious tasks,which in turn influenced the technological advancements and process change in the military.This paper summarizes the control-oriented integrated design of HSVs.First,the status of current research on the distinct characteristics and technique issues of HSVs is introduced.Then,the progresses made on complex modeling,guidance and control,and trajectory optimization are elaborated to exhibit the significant research interest in hypersonic technologies.The control-integrated design of HSVs is emphasized to solve the multidisciplinary design problems associated with the model and its control and trajectory.Various strategies regarding the multidisciplinary optimization design are also proposed to solve the integrated design problem.Finally,suggestions are provided for the control-oriented integrated design of HSVs.
文摘The purpose of this study is to contribute methodologically, through a systematic study of the application of different optimization techniques to design integrated distillation columns in binary, for it established one optimization technique, deterministic, was optimized distillation column at steady state. For this part was used tabu search to solve the type binary problem. For each choice of the search whole continuous variables were optimized with the deterministic method for process design perturbation is applied to the molar fraction of the feed. It develops and implements the mathematical algorithm solving the problem, then validation of the methodology proposed dynamic simulation of the system is compared with and without control, with both traditional and integrated approaches.
文摘A CAD tools environment is described to support concurrent collaborative design. The environment has four components: shared design representation, design process control, CAD tools, designer interface. Some related issues for the construction, such as form feature handling, constraint satisfaction, design process control, STEP based information integration, are discussed in more detail.
基金This project is supported by National Natural Science Foundation of China (No.59990470)Doctoral Foundation of Ministry of Education, China(No.20010487024).
文摘The integrated layout problem in manufacturing Systems is investigated. Anintegrated model for Concurrent layout design of cells and flow paths is formulated. A hybridapproach combined an enhanced branch-and-bound algorithm with a simulated annealing scheme isproposed to solve this problem. The integrated layout method is applied to re-layout the gear pumpshop of a medium-size manufacturer of hydraulic pieces. Results show that the proposed layout methodcan concurrently provide good solutions of the cell layouts and the flow path layouts.
基金Supported by the National Key Research and Development Program of China under Grant No 2017YFA0204600the National Natural Science Foundation of China under Grant No 61404002the Science and Technology Project of Hunan Province under Grant No 2015JC3041
文摘An analytical model for current-voltage behavior of amorphous In-Ga-Zn-O thin-film transistors(a-IGZO TFTs)with dual-gate structures is developed.The unified expressions for synchronous and asynchronous operating modes are derived on the basis of channel charges,which are controlled by gate voltage.It is proven that the threshold voltage of asynchronous dual-gate IGZO TFTs is adjusted in proportion to the ratio of top insulating capacitance to the bottom insulating capacitance(C_(TI)/C_(BI)).Incorporating the proposed model with Verilog-A,a touch-sensing circuit using dual-gate structure is investigated by SPICE simulations.Comparison shows that the touch sensitivity is increased by the dual-gate IGZO TFT structure.
文摘Die casting process is one of the prime options for m anufacturing precisely dimensioned, sharply defined metal parts. The design of d ie casting dies comprises several stages and entails a large amount of time. Tra ditionally, the different stages of the die design were not integrated but exist as separate entities. Moreover, recurring modifications or even redesigns are r equired due to the complexity in achieving an accurate initial die design. As a result, die design is usually time-consuming and costly with respect to resourc es. The die casting industry will greatly benefit if proper application software are developed that integrates the different die design stages and allows editin g of die design as and when needed. Hence it is imperative to create an integrat ed die design system that shortens the die design time. This paper presents a research that establishes a prototype of an integrated die design system. It is developed using the commercial SolidWorks CAD system and n amed DiWorks. The aim of building the system on a commercial CAD system is to ut ilise the resources and features of the CAD system to speed up the die design pr ocess. DiWorks consists of six distinct modules: Project Manager, Cavity Insert Builder, Gating System Constructor, Die Base Designer, Ejector System Constructo r and Standard Components Library. Through these six modules, the die designer c an create a complete die casting die beginning from a product part model. It is a user-friendly system that allows both experienced and novice die designers to easily accomplish the task of die design. The practical goal of this research is twofold: to develop a system that integra tes the die design process and at the same time facilitates the editing of d ie design during or after the course of the design process. The research approac h includes (i) parametric design, (ii) feature-based design (iii) system modeli ng and implementation. Parametric design deals with variable dimensions as contr ol parameters, and it is an efficient tool for creating models based on paramete rs. Parametric design not only increases the design efficiency, but also makes t he updates and modifications of existing designs easier and faster, since these can be achieved by changing the parameters of the parametric model. Feature-bas ed design is used to design a product with features that are functionally define d by attributes and are geometrically represented by a set of parameters. The re sults of this research will aid the automation of the die design process, thus i mproving the efficiency and quality of, and reducing the cost of die design.
文摘In this paper, sensitivity approaches are taken to analyze and design an integrated flight propulsion control system where the interaction between subsystems direitly affects the stability property and handling performances of the aircraft. The eigenvalue sen sitivity approach is employed to study the effect of coupling parameters on system stability and gain sensitivity approach is used to direct the reduced states feedback suboptimal control system design. Simulation results show that the integrated flight propulsion control system designed by sensitivity approaches is of good performance.
文摘This paper describes how database information and electronic 3D models are integrated to produce power plant designs more efficiently and accurately. Engineering CAD/CAE systems have evolved from strictly 3D modeling to spatial data management tools. This paper describes how process data, commodities, and location data are disseminated to the various project team members through a central integrated database. The database and 3D model also provide a cache of information that is valuable to the constructor, and operations and maintenance Personnel.