An Internet-enabled Integration of Concurrent Engineering with Co-design

In this paper,the Web-based integration methodology and framework have been developed to facilitate collabora- tive and concurrent engineering design in distributed manufacturing environments.The distributed concurrent engineering and co- design are discussed as key components in the mechanism.The related integration system is presented,which includes four function- al modules:co-design,Web-based visualization,manufacturing analysis and look-up service.It can be used for a design team geo- graphically distributed to organize a collaborative and concurrent engineering design effectively.In particular,the collaborative mechanism incorporated with Java-based and Internet-enabled technologies can generate extended strategies for design and planning. Thus,the proposed integration architecture enables the system to be generic,open and scalable.Finally,for the trend of global manufacturing,a case study of Internet-enabled collaborative optimization is introduced and a discussion on teamwork capability is made.

Mechanism for Integrating Sustainability in Engineering Design

This paper proposes an integration mechanism to help the owners and designers to integrate sustainability issues into design process, communicate with stakeholders and achieve consensus. Literature concerning engineering design, decision making and environment assessment were reviewed. Sustainability disputes in construction projects were analyzed and owners and designers were interviewed to understand the evolvement of these issues. Key success factors of other successful integration projects were also referenced. An integration mechanism including procedures was established along with traditional design process. Four integration steps were developed： organize integration team, propose integration issues, determine acceptance criteria, and evaluate alternatives; and four integration dimensions were also identified： appeals, decision making and execution, stakeholders, and experts. A matrix was formed by the four integration steps and four dimensions. A rigor index was proposed to measure the quality of the integration process. Finally, the mechanism was tested on a construction project with sustainability controversy to check its validity. The study results show that the integration mechanism can help incorporate sustainability issues and achieve consensus if followed rigorously. The integration matrix systematically examines the eight key integration factors under the four dimensions. The rigor index can explain the quality in integrating sustainability issues into engineering design. The mechanism provides a useful tool for the owners and designers to cope with the sustainability decision making difficulties.

Integrated Engineering Design and Data Management

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.

Civil Aircraft Assisted Space-Air-Ground Integrated Networks: Architecture Design and Coverage Analysis

In this paper, we propose a novel AIenabled space-air-ground integrated networks(SAGIN). This new integrated networks architecture consists of LEO satellites and civil aircrafts carrying aerial base stations, called "civil aircraft assisted SAGIN(CAA-SAGIN)". The assistance of civil aircrafts can reduce the stress of satellite networks, improve the performance of SAGIN, decrease the construction cost and save space resources. Taking the Chinese mainland as an example, this paper has analyzed the distribution of civil aircrafts, and obtained the coverage characteristics of civil aircraft assisted networks(CAAN). Taking Starlink as the benchmark, this paper has calculated the service gap of CAAN, and designed the joint coverage constellation. The simulation results prove that the number of satellites in CAASAGIN can be greatly reduced with the assistance of civil aircrafts at the same data rate.

A FRAMEWORK FOR APPLICATION OF SYSTEM ENGINEERING PROCESS MODELS TO SUSTAINABLE DESIGN OF HIGH PERFORMANCE BUILDINGS

Building owners,designers and constructors are seeing a rapid increase in the number of sustainably designed high performance buildings.These buildings provide numerous benefits to the owners and occupants to include improved indoor air quality,energy efficiency,and environmental site standards;and ultimately enhance productivity for the building occupants.As the demand increases for higher building energy efficiency and environmental standards,application of a set of process models will support consistency and optimization during the design process.Systems engineering process models have proven effective in taking an integrated and comprehensive view of a system while allowing for clear stakeholder engagement,requirements definition,life cycle analysis,technology insertion,validation and verification.This paper overlays systems engineering on the sustainable design process by providing a framework for application of the Waterfall,Vee,and Spiral process models to high performance buildings.Each process model is mapped to the sustainable design process and is evaluated for its applicability to projects and building types.Adaptations of the models are provided as Green Building Process Models.

航空发动机EngineCAD微机集成系统的开发与研究

本文介绍在航空发动机研制与改型设计阶段中采用最新技术的EngineCAD微机集成设计系统。该系统可以实现对涡喷、涡扇、涡轴和涡桨航空发动机部件图和总图的参数化实时设计,在参数化设计过程中提供发动机信息数据库、结构数据库的交互式查询,为设计提供所需的信息、数据和结构图形支持,可达到快速地生成供方案论证应用的各种航空发动机部件图、总图及各种信息,能快速实现多方案对比设计。具体应用表明,使用该系统大大缩短了设计周期,提高了设计的一次成功率。

基于ArcGIS Engine的飞机人工增雨航线自动化设计算法研究

人工增雨作为应急抗旱和缓解水资源紧张的重要手段,与社会经济可持续发展、生态安全和人民生活密切相关。航线设计是飞机人工增雨作业方案设计的一项重要内容,基于GIS平台自动化设计飞行航线将成为趋势。在传统飞行航线设计方案的基础上,研究提出了基于ArcGIS Engine的半圆弧过渡条播航线、"弓"字形条播航线和"之"字形条播航线三种层状云作业"穿云"航线与一种对流云或层积混合云作业"绕云"航线的自动化设计算法。应用结果显示,四种自动化算法均能够快速有效地设计出飞机航线,取得很好的效果。

Integration system research and development for three-dimensional laser scanning information visualization in goaf

An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, cloud data de-noising optimization, construction, display and operation of three-dimensional model, model editing, profile generation, calculation of goaf volume and roof area, Boolean calculation among models and interaction with the third party soft ware. Concerning this system with a concise interface, plentiful data input/output interfaces, it is featured with high integration, simple and convenient operations of applications. According to practice, in addition to being well-adapted, this system is favorably reliable and stable.

An Overview of Performance Characteristics, Experiencesand Trends of Aerospace Engine Bearings Technologies

In this paper, the operating conditions, technical requirements, performance characteristics, design ideas, application experiences and development trends of aerospace engine bearings, including material technology, integration design and reliability, are reviewed. The development history of aerospace engine bearing is recalled briefly at first. Then today＇s material technologies and the high bearing performances of the bearings obtained through the new materials are introduced, which play important roils in the aeroengine bearing developments. The integration design ideas and practices are explained to indicate its significant advantages and importance to the aerospace engine bearings. And the reliability of the shaft-bearing system is pointed out and treated as the key requirement with goals for both engine and bearing. Finally, as it is believed that the correct design comes from practice, the pre-qualification rig testing conducted by FAG Aerospace GmbH ＆ Co. KG is briefly illustrated as an example. All these lead to the development trends of aerospace engine bearings from different aspects.

A New Method for Optimum Allocation of Design Requirements in Aircraft Conceptual Design

A new method, Collaborative Allocation （CA）, is proposed to solve the large-scale optimum allocation problem in aircraft conceptual design. According to the characteristics of optimum allocation in aircraft conceptual design. The principle and mathematical model of CA are established. The optimum allocation problem is decomposed into one main optimization problem and several sub-optimization problems. A group of design requirements for subsystems are provided by the main system respectively, and the subsystems execute their own optimizations or further provide the detailed design requirements to the bottom components of aircraft, such as spars, ribs and skins, etc. The subsystems minimize the discrepancy between their own local variables and the corresponding allocated values, and then return the optimization results to main optimization. The main optimization is performed to reallocate the design requirements for improving the integration performance and progressing toward the compatibilities among subsystems. CA provides the general optimum allocation architecture and is easy to be carried out. Furthermore, the concurrent computation can also be realized. Two examples of optimum reliability allocation are used to describe the implementation procedure of CA for two-level allocation and three-level allocation respectively, and to validate preliminarily its correctness and effectiveness. It is shown that the developed method can be successfully used in optimum allocation of design requirements. Then taking weight requirement allocation as example, the mathematical model and solution procedure for collaborative allocation of design requirements in aircraft conceptual design are briefly depicted.

An Integrated Approach for Decision Support through Multi-objective Optimization with Application to an Ill-posed Design Problem

In the current scenario of global competition and short product life cycles, customer-defined satisfaction has attracted interest in artifact design. Accordingly, intelligent decision-making through multi-objective optimization has been proposed as an efficient method for human-centered manufacturing. However, previous vast researches on optimization have been mainly focused on optimization theory and optimization techniques and paid little interests on the process of problem formulation itself. In this paper, therefore, the authors present a total framework for supporting multi-objective decision making. Then, the authors try to solve the formulated multi-objective optimization problem that involves both qualitative and quantitative performance measures as a general consequence from the above procedure. Taking especially quality as a qualitative measure, the authors gave a new idea to evaluate the quality quantitatively. Additionally, to facilitate the portability of the proposed method in multidisciplinary decision-making environments, the authors implement the proposal algorithm in an Excel spreadsheet and validate the effectiveness of the approach through a case study.

基于ArcGIS Engine的空间信息项目一体化管理系统的研究

测绘和地理信息空间数据作用重要,但不易管理。为此,文章从生产单位实际工作管理需求出发,分析了传统数据管理的不足和弊端,提出了基于Arc GIS Engine的空间信息项目一体化管理系统的研发思路,实现了多元空间信息数据及项目信息快速入库、便捷调用、统一管理,为市县级测绘单位的数据管理提供了一种方法。

Gas exchange optimization in aircraft engines using sustainable aviation fuel:A design of experiment and genetic algorithm approach

The poppet valves two-stroke(PV2S)aircraft engine fueled with sustainable aviation fuel is a promising option for general aviation and unmanned aerial vehicle propulsion due to its high power-to-weight ratio,uniform torque output,and flexible valve timings.However,its high-altitude gas exchange performance remains unexplored,presenting new opportunities for optimization through artificial intelligence(AI)technology.This study uses validated 1D+3D models to evaluate the high-altitude gas exchange performance of PV2S aircraft engines.The valve timings of the PV2S engine exhibit considerable flexibility,thus the Latin hypercube design of experiments(DoE)methodology is employed to fit a response surface model.A genetic algorithm(GA)is applied to iteratively optimize valve timings for varying altitudes.The optimization process reveals that increasing the intake duration while decreasing the exhaust duration and valve overlap angles can significantly enhance high-altitude gas exchange performance.The optimal valve overlap angle emerged as 93°CA at sea level and 82°CA at 4000 m altitude.The effects of operating parameters,including engine speed,load,and exhaust back pressure,on the gas exchange process at varying altitudes are further investigated.The higher engine speed increases trapping efficiency but decreases the delivery ratio and charging efficiency at various altitudes.This effect is especially pronounced at elevated altitudes.The increase in exhaust back pressure will significantly reduce the delivery ratio and increase the trapping efficiency.This study demonstrates that integrating DoE with AI algorithms can enhance the high-altitude performance of aircraft engines,serving as a valuable reference for further optimization efforts.

An integrated turbocharger design approach to improve engine performance

Turbocharging technology is today considered as a promising way for internal combustion engine energy saving and CO2 reduction.Turbocharger design is a major challenge for turbocharged engine performance improvement.The turbocharger designer must draw upon the information of engine operation conditions,and an appropriate link between the engine requirements and design features must be carefully developed to generate the most suitable design recommendation.The objective of this research is to develop a turbocharger design approach for better turbocharger matching to an internal combustion engine.The development of the approach is based on the concept of turbocharger design and interaction links between engine cycle requirements and design parameter values.A turbocharger through flow model is then used to generate the design alternatives.This integrated method has been applied with success to a gasoline engine turbocharger assembly.

Design and optimization of a novel electrically controlled high pressure fuel injection system for heavy fuel aircraft piston engine

The heavy fuel compression ignition engines are widely equipped as aircraft piston engines. The fuel injection system is one of the key technologies that determines the performance of engine. One of the main challenges is to precisely control the injected fuel quantity and flow rate in the presence of pressure fluctuation. This challenge is even more serious for heavy fuel. An original design for electrically controlled high pressure fuel injection system called Multi-Pumppressure-reservoirs fuel injection System(MPS) was demonstrated to reduce the pressure fluctuation and help keep injection stable. MPS was compared with an ordinary high pressure Common Rail fuel injection System(CRS). This work established one-dimensional AMESim and mathematical models for both CRS and MPS to study the effect of different structures and geometric parameters on the pressure fluctuations. The calculations show that the average fuel pressure fluctuation of MPS can be reduced by 57% for the crankshaft speed of 1900 r/min, and the pressure fluctuation before injection reduced by 100%. It is concluded that the pressure performance of MPS is less sensitive to pressure reservoir volume than that of CRS, and there is an opportunity for further volume reduction.

Sensitivity Analysis for Safety Design Verification of General Aviation Reciprocating Aircraft Engine

This paper presents an application of global sensitivity analysis for system safety analysis of reciprocating aircraft engine. Compared with local sensitivity analysis results, global sensitivity analysis could provide more information on parameter inter- actions, which are significant in complex system safety analysis. First, a deterministic aviation reciprocating engine thermody- namics model is developed and parameters of interest are defined as random variables. Then, samples are generated by Monte Carlo method for the parameters used in engine model on the basis of definition of factor distribution. Eventually, results from engine model are generated and importance indices are calculated. Based on the analysis results, design is improved to satisfy the airworthiness requirements. The results reveal that by using global sensitivity analysis, the parameters could be ranked with respect to their importance, including first order indices and total sensitivity indices. By reducing the uncertainty of parameters and adjusting the range of inputs, safety criteria would be satisfied.

A Real-time Concurrent Product and Process Design System for Mechanical Parts

A real time concurrent product and process design system for mechanical parts is described in this paper. It consists of integrated product model, the expert system of product manufacturability evaluation and the controller of concurrent design. With the help of the controller of concurrent design, each feature of a part can be designed and evaluated based on manufacturing knowledge and resources, and can be modified according to the results of evaluation. The machining method of design feature can be selected based on manufacturing knowledge. So real time concurrent product and process design can be implemented based on integrated product model that is established based on generalized feature. Products and its design process can be optimized with the help of this system. The information and function integration of product design process can be realized. The time to market and the cost of products can be reduced.

新工科背景下“正/逆向设计加工”课程实践体系的探索与实践

阐述了长安大学现代工程训练中心建立的“正/逆向设计加工”课程实践体系的主要内容和实施效果。体系以教学融合+创新实践的方法进行构建,融合“CAD”“3D打印”“逆向工程”“CNC数控加工”等知识内容,采用递进式教学打破课程孤岛,鼓励学生自主创造,坚持全贯穿式教学实践环境。为培养新工科背景下的智能制造复合型人才提供了新型教学思路,对推动高校工程训练教学改革具有一定的借鉴意义。

新能源材料技术课程实施课程思政的设计及实践

在专业课程教学中融入课程思政是坚持立德树人、教书育人的需要。该文结合作者从事新能源材料技术课程教学的实际,深入挖掘该课程中的思政元素,并辅以适当的教学方法将职业道德教育、法律意识、环境保护理念和爱国主义教育等元素引入到课堂教学中,以此提高学生参与教学积极性,丰富材料相关专业教学内容,使学生在学习专业课程知识的同时思想道德素质得到全面提高。该文为专业课的课程思政实施提供有效案例,为材料专业人才落实立德树人根本任务、围绕培养目标、细化课程目标进行积极的探索,取得较好的效果。

模具设计卓越工程人才“三位一体、四方联动”产教融合培养模式探索与实践

在新时代、新经济和新工科背景下,培养大批能够适应模具产业发展和转型升级的模具设计卓越工程人才,越来越得到教育界与产业界的重视和关注。以产业需求为导向与以产教深度融合作为推进模具设计卓越工程人才培养的基本路径,创建了耦合教育链、人才链和产业链,政府搭建平台,以高校和企业为主导,第三方专业机构辅助的“三位一体、四方联动”校政企协同育人模式。该模式的创新之处是在政府、高校和企业之外,引入了既熟悉工程教育教学规律,又深谙企业生产实践的第三方专业机构,在政府的支持、调控与指导下,对接高校和企业,四方联合打造模具设计卓越工程人才培养协作共同体。该模式突破了传统校企合作的藩篱,解决了产教“联而不动、动而乏力”的问题,有效提升了材料成型和模具设计与制造专业毕业生与社会需求的契合度,促进了学生更加充分与更高质量的就业。