Early Design Evaluation Research Articles

Early design evaluation of low-rise school building morphology on energy performance: Climatic contexts of Southeast Europe

Contemporary societies have shifted their focus towards sustainable and resilient public buildings, transcending the institutional and functional role of the physical structures. School buildings remain the second highest expenditure of municipalities' total running costs. The impact on well-being and improved knowledge, and the average lifespan of school buildings, imply the necessity to pay special attention to its expected performance from the early design phase.The present research aims to estimate the impact of early design evaluation of open-school building morphology on energy performance in four climatic contexts of Southeast Europe. Design variables, including building shape and orientation, are selected for a comprehensive whole-building energy performance analysis. The results highlight the method's efficiency in reducing a maximum of 35.4% of the annual energy demand and increasing a maximum of 1.21 °C the thermal comfort in classrooms through geometry optimization. Suggestions are made on the appropriateness level of each typology for each studied climatic context. A fundamental framework for early design decision-making stages is generated through the performed simulation results.

Development of a process complexity index of low pressure die casting for early product design evaluation

The design of a product is key for the manufacturing industry to compete in the current era. Failure to plan a product design means losing in the market and falling behind competitors. One way to comprehensively evaluate one design is by analyzing its complexity. Complexity analyzes not only clear view parameters such as geometry and process time but also the whole design parameters, including its production process. This paper develops a process complexity index of low pressure die casting. A casting process is one unique process that depends on the melting and solidification of material in a die. A complexity analysis of low pressure die casting is yet to be done. Three different cylinder heads fabricated with low pressure die casting were used in the case study with the product’s types of 3SZ, 1TR, and 2TR. A process complexity analysis is performed based on the LPDC process’s physical and non physical parameters. The physical parameters are fixtures, tools, gauges, and machines. The non physical parameters are determined from the features and specifications of the low pressure die casting subprocess: setting, filling, solidification, and handling. The analysis successfully defines the complexity of each product, with 1TR having an index of 7.08, 2TR being 6.93, and 3SZ being 5.14. This developed complexity index can be utilized for early product design and cost estimation evaluation

Early Design Evaluation of School Building Morphology on Energy Performance: Climatic Contexts of Southeast Europe

Early Design Evaluation of School Building Morphology on Energy Performance: Climatic Contexts of Southeast Europe

Dynamic metrics of natural ventilation cooling effectiveness for interactive modeling

The evaluation of natural ventilation potential for cooling indoor spaces during the early design phases is of great interest to researchers and practitioners. Among various definitions and usages for natural ventilation potential (NVP) in early design evaluation, this paper reviews and identifies the key performance indicators, and proposes two new dynamic metrics—natural ventilation cooling effectiveness (NVCE) and climate potential utilization ratio (CPUR). The metrics are dynamically responsive to various design options, in both steady and transient states, allowing consideration of thermal mass. Assisting in design development processes, the metrics quantify how well indoor spaces make use of natural ventilation's cooling capacity. Case studies are presented to demonstrate how NVCE and CPUR enable designers to evaluate the predicted performance and how to apply the information to improve building design. The results of the design iterations showed that the relationship among various design parameters should be dynamically understood in order to evaluate the performance of natural ventilation, confirming that “the more the airflow, the greater the potential,” and “the heavier the thermal mass, the greater the energy saving” were not always true.

Holistic System Design Evaluation Through Expanded MATE

According to Buede and Miller, not applying a holistic simulation and modeling approach to early design evaluation practices and trade studies results in greater developmental costs, time to market, and unforeseeable system-level design consequences. Completed research is presented for an innovative methodology that enhances the capacity of conventional design evaluations by integrating new types of simulations consistently into the existing Multi-attribute Tradespace Exploration (MATE) design evaluation architecture. This enhancement is particularly important for any envisioned software-intensive system that introduces greater system complexity. According to Ross et al., MATE was originally developed to guide engineering design and initial product selection by exploring candidate designs to deliver utility-based solutions. Unfortunately, the MATE methodology does not support software design evaluation and integration into complex systems. The results presented validate MATE improvements that are scalable and extensible to any software-based system of varying complexity and application. The subject research provides proof of this concept by focusing on sensor systems as an initial practical demonstration due to their rapidly expanding commercial use and Internet of Things (IoT) applications. Project engineers and especially software developers in any product field will benefit from this design method by leveraging its holistic evaluation of software and hardware system design performance for more efficient product design identification and implementation.

Early Design Stage Evaluation of Thermal Performance of Battery Heat Acquisition System of a Hybrid Electric Aircraft

Abstract The electric energy and power storage, conversion and distribution (ESC&D) system of a hybrid electric aircraft, even at high efficiency, will reject significant heat at relatively low temperature. Thermal management systems (TMSs) can add excessive weight (heat exchangers and pumps) and impose excessive parasitic power consumption (pumps and fans) and drag (engine fan stream air and ram air) on the aircraft. Thus, effective low-weight thermal management of the ESC&D system is critical to realizing the potential benefits of a hybrid electric aircraft. This paper carries out early design stage benchmarking and evaluation of various thermal management approaches for the battery heat acquisition system of a hybrid electric aircraft. It is shown that the battery heat acquisition system based on state-of-the-art automotive electric vehicle design may be a third of the weight of the battery itself. Alternative approaches discussed here have the promise of reducing this weight by more than 60%.

Limitations of Air/Water Testing in the Development of High Performance Trays

Retrofitting distillation columns with higher capacity mass transfer internals is an effective way of increasing productivity. In the last decades, tray research and development has focused on two areas – improvement of downcomer designs and development of high performance valves with the target to handle higher vapor loads. An example for the second approach is the development of the new Sulzer UFM™ valve. This paper discusses Sulzer’s experience with laboratory testing strategies for fractionation trays and limitation of hydraulic tests with water and air.Air/water testing is very popular due to the low cost and its simplicity. It is still considered as a reliable starting point for screening design options and to evaluate feasibility and capacity. The beginnings of the Sulzer UFM valve development followed this path, but soon weaknesses of the air/water test system were found. Prototype designs preceding the Sulzer UFM valve showed very promising results. Consequently, they were further optimized using air/water for maximum hydraulic capacity. But subsequent distillation tests using a standard binary test system at total reflux could not confirm previous findings. A reduction in liquid entrainment, as observed with water, does not necessarily lead to a capacity increase in distillation. The chosen testing strategy was obviously not efficient and disadvantageous regarding cost and timing.A more successful development path adds more weight to distillation testing, specifically in the early design evaluation phase, but air/water hydraulic tests are not entirely abandoned. Consequently, the later valve designs, currently known as the Sulzer UFM valve, were mainly performed in Sulzer’s 1000mm distillation column and external distillation columns of industrial size.

The Konect value – a quantitative method for estimating perception time and accuracy for HMI designs

ABSTRACTA human operator monitoring a safety-critical system has to perceive information quickly and accurately to detect critical system states and execute countermeasures in time. So far, testing such human machine interfaces (HMIs) is a complex task as HMI design prototypes have to be implemented for simulation environments to perform tests with professional operators. We propose Konect Value, a quantitative method to estimate the relative perception accuracy and operator reaction time at an early design stage. The model-based method solely requires a task model and HMI design sketches as input. To validate the Konect Value, we applied the quantitative measure to seven different HMIs in a truck platooning use case. A comparison of the calculated value to the measured accuracy and reaction times in a lab study (n=33) revealed high correlations for the relative reaction time (r=0.83, p<0.05) and relative perception accuracy (r=−0.90, p<0.01). This indicates that Konect Value is a promising method for early HMI design evaluation in the safety-critical system domain.

Parametric analysis of glenoid implant design and fixation type.

Common post-operative problems in shoulder arthroplasty such as glenoid loosening and joint instability may be reduced by improvements in glenoid design, shape, material choice, and fixation method. A framework for parametric analysis of different implant fixation configurations was developed in order to efficiently sift through potential glenoid component designs. We investigated the influence of design factors such as fixation type, component thickness, and peg position, number, diameter, and length in a multi-factorial design investigation. The proposed method allowed for simultaneous comparison of the mechanical performance of 344 different parametric variations of 10 different reference geometries with either large central fixation features or small peripheral pegs, undergoing four different worst-case scenario loading conditions, and averaging 64.7 s per model. The impact of design parameters were assessed for different factors responsible for post-operative problems in shoulder arthroplasty, such as bone volume preservation, stresses in the implant, central displacement or fixation stability, and the worst performing geometries all relied on conventional central fixation. Of the remaining geometries, four peripheral fixation configurations produced von Mises stresses comfortably below the material's yield strength. We show that the developed method allows for simple, direct, rapid, and repeatable comparison of different design features, material choices, or fixation methods by analyzing how they influence the bone-implant mechanical environment. The proposed method can provide valuable insight in implant design optimization by screening through multiple potential design modifications at an early design evaluation stage and highlighting the best performing combinations according to the failure mechanism to mitigate. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:775-784, 2017.

A formal framework for service modeling and prototyping

Abstract Service-oriented Computing is rapidly gaining importance across several application domains due to its capability of composing autonomous and loosely-coupled services. In order to support the engineering of service-oriented software applications, foundational theories, service modeling notations, evaluation techniques fully integrated in a pragmatic software engineering approach are required. This article introduces a framework for modeling and prototyping service-oriented applications. The framework consists of a precise and executable language, SCA-ASM , for model-based design, and of a tool for early and quick design evaluation of service assemblies. The language combines the OASIS/OSOA standard Service Component Architecture (SCA) capability of modeling and assembling heterogeneous service-oriented components in a technology agnostic way, with the rigor of the Abstract State Machine (ASM) formal method able to model notions of service behavior, interactions, orchestration, compensation and context-awareness in an abstract but executable way. The tool is based on existing execution environments for ASM models and SCA applications. An SCA-ASM model of a service-oriented component, possibly not yet implemented in code or available as off-the-shelf, can be (i) simulated and evaluated offline , i.e. in isolation from the other components; or (ii) executed as abstract implementation (or prototype ) together with the other components implementations according to the chosen SCA assembly. As proof of concept, a case study taken from EU research projects has been considered to show the functionalities and potentialities of the proposed framework.

Potential model for single-sided naturally ventilated buildings in China

The paper investigates a single-sided naturally ventilated buildings potential model considering number of factors in China. This model can be used to estimate potential of natural ventilation via local climate data and building parameters. The main goal of the model is to predict natural ventilation hours and hourly ventilation flow rate. In fluid model, formula of single-sided natural ventilation by coupling wind pressure and temperature difference was used to calculate air flow rate. Accordingly, the paper analyzed four typical cities in different climate region in China and calculated pressure difference Pascal hours (PDPH). The results show that single-sided ventilation has fewer adaptive comfort hours than two-sided ventilation and much less ventilation volume. This model provided quantitative information for early stage architectural natural ventilation design and building energy efficiency evaluation.

Large volume metrology process models: A framework for integrating measurement with assembly planning

This paper describes a generic methodology dealing with the theoretical definition of metrology process models and their systematic integration with design evaluation and assembly planning. The research resulted in the specification of a novel, theoretical framework for the specification and generation of metrology process models, especially focusing on large volume, frameless metrology that is suitable for the verification of large and complex products. The process modelling framework has four generic sections that support early design evaluation, assembly process interface, set-up and deployment, and verification data management. Initial testing results, using aerospace products, demonstrated the effectiveness of the process modelling methods.

More Than Skin Deep: Early Design Evaluation Tools

More Than Skin Deep: Early Design Evaluation Tools

An improved methodology for evaluating the producibility of partially specified part designs

Within the concurrent engineering (CE) paradigm, products must be designed in light of downstream lifecycle preferences and capabilities. One CE challenge is the need to estimate the downstream implications of partially specified part designs as earlyas possible in the design cycle.In this research, the hierarchical evaluation methodology for early design (HEMED) was developed to address this challenge for the fixed-principle design environment in the piece-part manufacturing industry. A prescriptive decision modelling approach was used to develop this methodology. HEMED models a company's preferences and priorities using a weighted hierarchy of business objectives, and it uses utility scoring logic to evaluate a part design's performance relative to these priorities. Utility scores are aggregated in a bottom-up manner to generate the part design's HEMED rating, which consists of both a score and its associated uncertaintyfactor for each objective in the hierarchy. Aprototype, proof-of-concept HEMED design-rating system was implemented and verified at a local aerospace manufacturing company. Several of the company's experienced production engineers believed that the HEMED prototype, while limited in scope, accurately represented their organization's preferences and priorities. They also believed that the prototype's test part ratings were accurate compared to their first-hand experience with these parts. HEMED was also compared to the other documented and validated earlydesign evaluation methodologybya total of 28 engineers and technical managers from two aerospace manufacturing companies. For 11 of the 12 criteria that were used to rate the two methodologies, the evaluators believed that HEMED was an improvement within the fixed-principle design environment. This research demonstrated that HEMED was an improvement over the previously documented early design-rating system within the aerospace manufacturing industry. With additional testing, the researchers strongly believe that HEMED can be successfully applied and demonstrated as an improved early design evaluation approach throughout the piece-part manufacturing industry.

FUNCTION METRICS FOR ENGINEERED DEVICES

Function metrics make early design evaluation possible. A simple definition of function as a pair of behavior expressions that map the utilized part of a component behavior to an intended part of a device behavior enables formal definition of several useful metrics for engineered devices such as sharing, overload, modularity, and criticality. These function metrics can be used to evaluate properties of a given configuration of components in a device as well as to compare alternative configurations of devices for the same design intents. A program called Teleometrics has been implemented that models function representations of devices as graphs and generates function metrics. Four patented accelerometers used for automotive crash sensing are modeled, evaluated, and compared using Teleometrics.