Showing papers on "Design tool published in 2008"

Analogies and metaphors in creative design

Abstract: In our increasingly flat and connected world, skills in innovation and creative design have emerged as key attributes for graduating engineering designers. Metaphors and analogies are commonly voiced as key tools for enhancing creative design yet little research has been performed on their relation to each other and their use within the design process. In this paper we discuss the relationship between metaphor and analogy use in the design process, with a focus on engineering education. We support our discussion with results from interviews and experiments with student designers. Our results highlight that both metaphor and analogy are spontaneously used by student designers and that metaphor dominates as the design tool for early problem-framing design phases whereas analogy dominates as a tool for concept generation. We also present an analysis of the metaphors for our understanding of design in use within Germany, the UK and Mexico. We found an 85 per cent overlap between textbook usages of metaphors in conceptual design in these countries as compared to textbooks authored in the United States, suggesting that cross-cultural differences in design understanding are relatively small in higher education. We close by presenting a design by analogy method to promote and enhance the use of analogy as a skill for graduating engineering designers.

Dividing Wall Distillation Columns: Optimization and Control Properties

Abstract: The optimal design of dividing wall columns is a non-linear and multivariable problem, and the objective function used as optimization criterion is generally non-convex with several local optimums. Considering this fact, in this paper, we studied the design of dividing wall columns using as a design tool, a multi-objective genetic algorithm with restrictions, written in MatlabTM and using the process simulator Aspen PlusTM for the evaluation of the objective function. Numerical performance of this method has been tested in the design of columns with one or two dividing walls and with several mixtures to test the effect of the relative volatilities of the feed mixtures on energy consumption, second law efficiency, total annual cost, and theoretical control properties. In general, the numerical performance shows that this method appears to be robust and suitable for the design of sequences with dividing walls.

Digital Simulations for Improving Education: Learning Through Artificial Teaching Environments

Abstract: Game-based learning and simulation is a powerful mode of learning, used by industries as diverse as aviation and health sciences. While there are many generic Virtual Learning Environments available to further education and higher education in the United Kingdom, there is no widely available open-source Web-based simulation environment for professional learning. The SIMPLE (SIMulated Professional Learning Environment) project has designed, created, implemented and is in the process of evaluating such an environment in a range of disciplinary settings. The simulations that are being created place both undergraduates and postgraduates in a professional context where their work is, as it will be in the workplace, distributed between tools, colleagues, resources, anticipated, and unanticipated problems. One of the key tools that staff will use to create simulations is the “narrative event diagram”, a design tool as well as a means by which the narrative of the simulation is constructed. This chapter will describe the tool, its design history and context, its current use, and next design iteration. In particular it will show the interdisciplinary genesis of the tool’s design, arising from the confluence of computer science, information science, and narrative theory, and its power in designing professional educational simulations.

Multidisciplinary Integrated Preliminary Design Applied to Unconventional Aircraft Configurations

Abstract: A preliminary aircraft design tool is presented as a means of performing multidisciplinary, integrated preliminary design of unconventional aircraft configurations. Higher fidelity numerical methods for some of the involved disciplines are discussed as key elements of this process. A noise propagation module is described as a first step toward introducing aircraft noise analysis into the preliminary design process. Application of the tool to a specific unconventional aircraft concept is shown. The results of this study provide an understanding of why multidisciplinary design analysis and optimization, as well as higher fidelity methods, are required for the design of unconventional aircraft configurations.

Virtual Laboratory for Creative Control Design Experiments

Abstract: This paper proposes a two-step strategy for the computer-aided learning of control. A virtual Web-based laboratory for control design experiments (http://www.hl1.uni-mb.si), which supports a two-step strategy, is based on the MATLAB Web server (MWS) and consists of two virtual laboratories. The first virtual laboratory, called ldquoWeb sisotool,rdquo supports computer-aided control design and structured hands-on experiments. Computer-aided control design is welcome as a design tool while structured hands-on experiments are welcome for the visualization of hard-to-grasp concepts. The second virtual laboratory offers students an unstructured MATLAB-like environment, called ldquoM-file application,rdquo that allows students to create and design control design experiments by writing MATLAB M-files of their own and executing them on MWS. The presented virtual laboratory for control design experiments is cost effective and has already been successfully used for the learning of control. Student feedback is also presented.

Human experience and product usability : principles to assist the design of user-product interactions

Abstract: This paper introduces research that investigates how human experience influences people's understandings of product usability. It describes an experiment that employs visual representation of concepts to elicit participants' ideas of a product's use. Results from the experiment lead to the identification of relationships between human experience, knowledge, and context-of-use – relationships that influence designers' and users' concepts of product usability. These relationships are translated into design principles that inform the design activity with respect to the aspects of experience that trigger people's understanding of a product's use. A design tool (ECEDT) is devised to aid designers in the application of these principles. This tool is then trialled in the context of a design task in order to verify applicability of the findings.

CFD-RANS Study of Horizontal Axis Wind Turbines

Abstract: This PhD project concerns the study of wind turbine aerodynamics with a CFD–RANS approach. Nowadays, industrial design codes for wind turbines are still based on the BEM (Blade Element Momentum) method, which has been extended with a number of empirical correction, often not based on physical flow features. The importance of accurate design does also increase as the machines tend to become larger. Therefore, the research is today focused more on the basic aerodynamic mechanisms. The general aim of this project was to get a better understanding of the physical behaviour of the flow field past wind turbine rotors, including the boundary layer flow as well as the wake region. Although CFD is not a practical design tool, useful suggestions for classical design methods can be derived from the analysis. A full three–dimensional CFD–RANS approach was used, modelling the whole rotor of a wind turbine by means of periodicity and in a moving reference system. All the simulations were performed using the finite–volume solution package Fluent®. A detailed selection of results is presented, dealing with the various investigated issues. A first validation of the computational methods was done by comparing the overall power production of a BEM-designed turbine. The most important features of the investigated machines were captured with CFD, so that a broad review of wind turbine aerodynamics was given, through the post processing of the computed solutions. A study on the blade root and tip was carried out, allowing to demonstrate the advantages of some recent improvements in rotor blade design, and showing the capabilities of CFD as an optimization method. Both the near and far wake were also analysed. Finally, the rotational effect on the boundary layer of rotating blades were studied, with generating a complete solution database and a post–processing tool. Further advancements are required, for stating more about the complex issues, as wake dynamics and rotational effects are. Nevertheless, the purpose of proving the capabilities of full–3D CFD–RANS for the study wind turbine aerodynamics has been fully achieved.

Limitations of the House of Quality to provide quantitative design information

Abstract: Purpose – The House of Quality (HoQ) is a popular design tool that supports information processing and decision making in the engineering design process. While its application is an aid to conceptual aspects of the design process, its use as a quantitative information tool in engineering design is potentially flawed. This flaw is a result of potential designer interpretation of the HoQ results – interpretation which is invalid given the assumptions and information sources behind the HoQ – and is viewed as a critical limitation on the results of the method which can lead to potentially invalid and/or poor decisions. In this paper this limitation and its implications are explored both experimentally and through simulated application.Design/methodology/approach – The approach taken in this research is to first study the HoQ through a “digital experiment” in order to identify the key factors that drive the quantitative results within the tool. Based on the results of the experiment, an example HoQ for a hair ...

Bond Graph Based Automated Modeling for Computer-Aided Design of Dynamic Systems

Abstract: This paper introduces research leading to a computer-aided design tool in which engineering designers can test various design concepts (topologies) in an environment equipped to automatically model the dynamics and conveniently optimize the specified components (given the evaluation criteria defined by human designers). A component repository is developed to store not only the component dynamics models, but also other information such as typical component design constraints and physical constitutive laws. In this paper, automated modeling of design configurations is introduced through a design representation called a conceptual dynamics graph (CD graph) and generic models of various components. CD graphs contain the information on how physical components as well as their generic models are topologically connected. A generic component model can accommodate various types of coupling between this component and its environment. This paper also discusses a systematic approach to automatically prepare a mechatronic design problem for the use of optimization to tune the parameters for optimum dynamics. Since genetic algorithms are used for this optimization, this preparation decodes and encodes proper design variables into design genotypes while taking into consideration the design constraints and physical constitutive laws.

Personas and scenarios: design tool or a communication device?

Abstract: Using personas and scenarios is one way of working with usability in system development projects. In this paper we describe our experience of using the personas and scenarios within a large, on-going European research project called NEPOMUK. We describe the project background as well as the project work with the purpose of critically examining how the persona method has been applied within the project. Our conclusion is that the persona method has been most useful for translating the users’ context to be understood by the project stakeholders and in promoting the idea of user-centred design. However, it has been less successful as a design tool.

Virtual testing of realistic aerospace composite structures

Abstract: The feasibility of using simulation of component tests to failure is examined from the view of using this as a design tool to reduce time and costs for future aircraft designs. All aspects are considered, that is modelling correctly the physics of failure mechanisms, having an acceptable CPU time, and ease of interfacing with existing CAE systems for generating models and processing the results. By looking at many benchmarks (including an industrial component) with experimental validation, it is concluded that simulation is now a feasible design tool and that many more searching examples will lend credibility to this strategy for both manufacturers and certification authorities.

Design and Construction Modifications of Switched Reluctance Machines

Abstract: Although the design principles of the Switched Reluctance Machines (SRMs) are available in different fragments in numerous bibliography positions, there no exists the complex design procedure of whole drive system taking into account the SR Machine, control system and supply device as well. The hybrid design method for SRM drives with application of new analytical calculation methods, finite element method and simulation models is proposed in this thesis. The calculation/design system is characterised by important effectivity and reliability. The new possibilities in analytical determination of saturation effects and core losses under various modes of control, including sensorless method, are also taken into account. The correctness of the proposed design algorithms are verified by laboratory tests made on three motor prototypes manufactured in industry for concrete application. This dissertation provides the elements indispensable for more accurate and complex analysis and design of drives with switch reluctance motors. The elements of electrical motor and control system design as well as the considerations on the choice of supply device and controller subsystems are jointed in the thesis for final receiving of the design tool for considered industrial drive system.

Prometheus design tool

Abstract: The Prometheus Design Tool (PDT) supports the structured design of intelligent agent systems. It supports the Prometheus methodology, but can also be used more generally. This paper outlines the tool and some of its many features.

An Optimization Technique for Radial Compressor Impellers

Abstract: A software tool has been created to aid in automated impeller design within an integrated design system for radial flow impellers. The design tool takes the results from the 1D preliminary design process and uses these to define a parameterized blade geometry, which incorporates features that are required for low mechanical stresses and simple manufacturing. This geometry is then adjusted to minimize a global objective function using a throughflow computation. The adjustment is based on selection with a breeder genetic algorithm. The initial population includes “elite” designs from a database of earlier well-proven experience, and the final design is honed to perfection with a hill-climbing method. With the help of a suitable global objective function incorporating mechanical and aerodynamic criteria, and taking into account wide experience with the design of impellers, the tool provides a fast screening of various design possibilities to produce a geometrical input for more advanced computational fluid dynamic and mechanical analysis. This is demonstrated through the redesign of an impeller previously designed by conventional methods. Comparisons of the results of the CFD analysis of the new impeller with that of the earlier design demonstrate that the tool can rapidly produce nearly optimal designs as an excellent basis for further refinement by the more complex analysis methods.Copyright © 2008 by ASME

Genr8: Architects’ Experience with an Emergent Design Tool

Abstract: We present the computational design tool Genr8 and six different architectural projects making extensive use of Genr8. Genr8 is based on ideas from Evolutionary Computation (EC) and Artificial Life and it produces surfaces using an organic growth algorithm inspired by how plants grow. These algorithms have been implemented as an architect’s design tool and the chapter provides an illustration of the possibilities that the tool provides.

Memic: An Interactive Morphological Matrix Tool for Automated Concept Generation

Abstract: Advancement in product design is usually made by building on previous experiences and learning from past successes and failures. However, knowledge transfer in the broad field of product design is often difficult to accomplish. Research has shown that successful component configurations, observed from existing products, can be dissected and stored for reuse; but few computational tools exist to assist designers during the conceptual phase of design. Many well-known manual concept generation methods (e.g. brainstorming, intrinsic and extrinsic searches, and morphological analysis) rely heavily on individual bias and experience and are generally laborious tasks that may not draw upon a wide enough solution space. This research presents an automated design tool that augments traditional activities during the conceptual phase of design. The interactive morphological matrix (or MEMIC, the Morphological Evaluation Machine and Interactive Conceptualizer) draws on knowledge contained within a repository of existing design solutions to quickly produce numerous feasible concepts early in the design process, which each satisfy the functional requirements for a design problem. By quickly presenting numerous concepts from products that have already been developed, this design tool provides a broader set of initial concepts for evaluation than a designer may generate alone when limited by his/her personal experiences.

A Variable Fidelity Model Management Framework for Designing Multiphase Materials

Abstract: Research applications involving design tool development for multi phase material design are at an early stage of development The computational requirements of advanced numerical tools for simulating material behavior such as the finite element method (FEM) and the molecular dynamics (MD) method can prohibit direct integration of these tools in a design optimization procedure where multiple iterations are required One, therefore, requires a design approach that can incorporate multiple simulations (multiphysics) of varying fidelity such as FEM and MD in an iterative model management framework that can significantly reduce design cycle times In this research a material design tool based on a variable fidelity model management framework is presented In the variable fidelity material design tool, complex "high-fidelity " FEM analyses are performed only to guide the analytic "low-fidelity" model toward the optimal material design The tool is applied to obtain the optimal distribution of a second phase, consisting of silicon carbide (SiC) fibers, in a silicon-nitride (Si 3 N 4 ) matrix to obtain continuous fiber SiC-Si 3 N 4 ceramic composites with optimal fracture toughness Using the variable fidelity material design tool in application to two test problems, a reduction in design cycle times of between 40% and 80% is achieved as compared to using a conventional design optimization approach that exclusively calls the high-fidelity FEM The optimal design obtained using the variable fidelity approach is the same as that obtained using the conventional procedure The variable fidelity material design tool is extensible to multiscale multiphase material design by using MD based material performance analyses as the high-fidelity analyses in order to guide low-fidelity continuum level numerical tools such as the FEM or finite-difference method with significant savings in the computational time

A Markovian Performance Model for Networks-on-Chip

Abstract: Network-on-chip (NoC) has been proposed as a solution for addressing the design challenges of future high-performance nanoscale architectures. Thus, it is of crucial importance for a designer to have access to last methods for evaluating the performance of on-chip networks. To this end, we present a Markovian model for evaluating the latency and energy consumption of on-chip networks. We compute the average delay due to path contention, virtual channel and crossbar switch arbitration using a queuing-based approach, which can capture the blocking phenomena of wormhole switching quite accurately. The model is then used to estimate the power consumption of all routers in NoCs. The performance results from the analytical models are validated with those obtained from a synthesizable VHDL-based cycle accurate simulator. Comparison with simulation results indicate that the proposed analytical model is quite accurate and can be used as an efficient design tool by SoC designers.

New design tools for LED headlamps

Abstract: The automotive lighting technology is in considerable progress due to new components, e.g., High-Power-LEDs and light guides, and new sophisticated production techniques. Furthermore, great importance is being attached to the appearance of front and tail lamps. White High-Power-LEDs have reached a development stage that affords its reasonable application to low beam headlamps. This challenging illumination function requires sophisticated design techniques in order to preserve the advantages associated with this source type. Thus, high efficiency and stylish appearance have to be reconciled, e.g., with the use of freeform surfaces. Beside the demands from manufacturers and customers, car lamps have to meet several regulations (ECE, SAE, etc.). This contribution describes the illumination design of a LED-based low beam headlamp using advanced mathematical methods, e.g., 3D-Tailoring, automatic optimization, and Virtually Reflecting/Refracting Surfaces (VRS). We propose this new surface type with non conventional reflection/refraction properties as an advantageous design tool for the first layout and for automatic optimization, as well. For efficiency reasons, special attention will be paid to the creation of the cut-off line without using additional stops.

Practical Asynchronous Interconnect Network Design

Abstract: The implementation of interconnect is becoming a significant challenge in modern integrated circuit (IC) design. Both synchronous and asynchronous strategies have been suggested to manage this problem. Creating a low skew clock tree for synchronous inter-block pipeline stages is a significant challenge. Asynchronous interconnect does not require a global clock, and therefore, it has a potential advantage in terms of design effort. This paper presents an asynchronous interconnect design that can be implemented using a standard application-specific IC flow. This design is considered across a range of IC interconnect scenarios. The results demonstrate that there is a region of the design space where the implementation provides an advantage over a synchronous interconnect by removing the need for clocked inter-block pipeline stages, while maintaining high throughput. Further results demonstrate a computer-aided design tool enhancement that would significantly increase this space. A detailed comparison of power, area, and latency of the two strategies is also provided for a range of IC scenarios.

Automated sizing of permanent magnet synchronous machines with respect to electromagnetic and thermal aspects

Abstract: The design of modern high power density permanent magnet synchronous machines requires adapted automated design tools. The temperature estimation at characteristic points of the machine, and in particular in permanent magnets, is essential to accurately simulate the electromagnetic behavior and avoid irreversible demagnetization. In this paper, an electromagnetic dimensioning model, parameterized by FEA, is coupled to a thermal lumped-parameter model to constitute a fast and efficient design tool for electrical machines. On two standard industrial servo-motors the whole design process, including sizing, electromagnetic and thermal modeling is applied and discussed.

Design of Nonlinear Lead and/or Lag Compensators

Abstract: A known nonlinear compensator design approach is adapted to allow design of nonlinear lead and/or lag compensators, and a number of MATLAB functions are developed that automate the compensator design procedure. With this design tool, control engineers would be able to rapidly design nonlinear lead and/or lag compensators. An example of a tutorial nature is presented.

Rotman lens design and simulation in software [Application Notes]

Abstract: Since its invention in the early 1960s (Rotman and Turner, 1963), the Rotman Lens has proven itself to be a useful beamformer for designers of electronically scanned arrays. Inherent in its design is a true time delay phase shift capability that is independent of frequency and removes the need for costly phase shifters to steer a beam over wide angles. The Rotman Lens has a long history in military radar, but it has also been used in communication systems. This article uses the developed software to design and analyze a microstrip Rotman Lens for the Ku band. The initial lens design will come from a tool based on geometrical optics (GO). A second stage of analysis will be performed using a full wave finite difference time domain (FDTD) solver. The results between the first-cut design tool and the comprehensive FDTD solver will be compared, and some of the design trades will be explored to gauge their impact on the performance of the lens.