| 19971. |
- Poulikidou, Sofia, 1984-
(författare)
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Assessing design strategies for improved life cycle environmental performance of vehicles
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Vehicle manufactures have adopted different strategies for improving the environmental performance of their fleet including lightweight design and alternative drivetrains such as EVs. Both strategies reduce energy during use but may result in a relative increase of the impact during other stages. To address this, a lifecycle approach is needed when vehicle design strategies are developed. The thesis explores the extent that such a lifecycle approach is adopted today and assesses the potential of these strategies to reduce the lifecycle impact of vehicles. Moreover it aims to contribute to method development for lifecycle considerations during product development and material selection.Current practices were explored in an empirical study with four vehicle manufacturers. The availability of tools for identifying, monitoring and assessing design strategies was explored in a literature review. The results of the empirical study showed that environmental considerations during product development often lack a lifecycle perspective. Regarding the use of tools a limited number of such tools were utilized systematically by the studied companies despite the numerous tools available in literature.The influence of new design strategies on the lifecycle environmental performance of vehicles was assessed in three case studies; two looking into lightweight design and one at EVs. Both strategies resulted in energy and GHG emissions savings though the impact during manufacturing increases due to the advanced materials used. Assumptions relating to the operating conditions of the vehicle e.g. lifetime distance or for EVs the carbon intensity of the energy mix, influence the level of this tradeoff. Despite its low share in terms of environmental impact EOL is important in the overall performance of vehicles.The thesis contributed to method development by suggesting a systematic approach for material selection. The approach combines material and environmental analysis tools thus increases the possibilities for lifecycle improvements while minimizing risk for sub-optimizations.
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| 19972. |
- Poulikidou, Sofia
(författare)
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Integration of Design for Environment in the vehicle manufacturing industry in Sweden : Focus on practices and tools
- 2013
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Design for Environment (DfE) promotes the systematic consideration of environmental aspects during product design and development. Despite the maturity of concepts and tools in literature, efficient implementation in industries is reported to be low. A need to bridge this gap is identified with studies that look on DfE practices as well as the use and potential of DfE tools.This thesis is part of a research project that investigates DfE practices and the use of tools during vehicle design and development. The aim is to investigate the ways that environmental constraints can be efficiently integrated into product development processes thus assist in improving the environmental performance of products from a life cycle perspective. The scope of the study includes four vehicle manufacturing companies in Sweden. The development and utilization of tools has been also investigated aiming to increase the opportunities for effective use within this product category. Case study methodology, research interviews and literature reviews constitute the research strategy followed in this work.The empirical results presented in this thesis indicated that vehicle manufacturing companies in Sweden are continually working to improve the environmental performance of their products and meet legal and costumer demands. Despite similarities regarding the type of environmental requirements considered, the companies studied have adopted different ways to identify and integrate environmental requirements into their product development process and use DfE tools to different extents. Such variations reflect differences in the success and maturity levels of the DfE practices adopted.A need for increased and more systematic use of tools is identified for all studied companies and especially for analytical tools. Results from the literature review showed that a variety of tools are available that have the potential to support vehicle design processes. However, only a few cover a broad set of aspects identified to be relevant from a vehicle design perspective. For DfE tools to become effective and be used during product development, they need to cover aspects that are relevant for the company and product designers. A need towards the development of tools that assist vehicle or product designers in general, to make informed and comprehensive choices based on a variety of requirements associated to the product, is identified.
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| 19973. |
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| 19974. |
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| 19975. |
- Poulikidou, Sofia, 1984-
(författare)
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Overview and classification of Design for Environment tools – A diverse toolbox for vehicle developers
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Design for environment (DfE) tools, are defined as any type of systematised aid that facilitates the integration of environmental considerations during product development. A variety of DfE tools is available and informed selection based on the company’s, user’s and product’s needs is important for their successful implementation. Through systematic review of the literature, the goal of this paper is to provide a compilation of DfE tools that can be used during vehicle design and development processes. The review resulted in a rich and diverse toolbox of 41 DfE tools the majority of which exhibiting features that are relevant from a vehicle design perspective, such as environmental impacts that are important to monitor for this product category, life cycle considerations, functional and regulation requirements and more. No tool covers all features thus the use of a combination of tools may be necessary. By collecting and presenting the DfE tools available, this paper is expected to assist the adoption and systematic use of existing tools. Gaps and limitations are identified, indicating areas for improvement, for the development of future tools.
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| 19976. |
- Poulikidou, Sofia, et al.
(författare)
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Overview of Design for Environment tools and investigation of their application potential within vehicle design and development processes
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- This paper provides a compilation of 31 Design for Environment (DfE) tools that are available today and investigates the potential of those tools to be used during vehicle design processes. The assessment is based on a variety of parameters that cover methodological characteristics of the identified tools but also aspects that are relevant from a vehicle design perspective. The results show that product developers have a rich and diverse toolbox where suitable tools can be selected. When it comes to vehicle design, combinations of DfE tools have the potential to capture the parameters and requirements considered. The paper identifies a need for tools that manage to integrate a multi-criteria perspective related to vehicle design i.e. by incorporating environmental, functional, economic, stakeholder’s and regulation requirements but also for tools that provide possibilities for integration into engineering tools.
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| 19977. |
- Poulikidou, Sofia, et al.
(författare)
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Tools for sustainable product development : experience and requirements from the vehicle manufacturing industry in Sweden
- 2013
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Ingår i: Perspectives on managing life cycles. - 9789198097351 ; , s. 573-576
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents an empirical study on the use of tools for sustainable product development at four vehicle manufacturing companies in Sweden. Different tools that are used in the studied companies are identified and listed while the obstacles and needs for an increased and successful use of those tools are discussed. The study shows that a limited number the identified tools are used in a systematic way, for instance product specific tools that monitor regulation requirements. Impact assessment tools are applied more centrally in the companies with less integration to the design process. However, interest on the available tools has increased and on the ways that such tools can assist and influence design decisions in a more efficient way.
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| 19978. |
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| 19979. |
- Pouransari, Zeinab, et al.
(författare)
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DNS analysis of wall heat transfer and combustion regimes in a turbulent nonpremixed wall-jet flame
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Understanding the heat-release effects on the wall heat transfer in turbulent reacting flows, i.e. heat transfer with or without significant density variation, is essential for a wide variety of industrial flows, especially combustion problems. The present study focuses on the wall heat transfer and the near-wall reaction characteristics. The heat-release effects on the wall heat transfer and skin friction coefficients are investigated using three-dimensional direct numerical simulations of a turbulent reacting wall-jet flow with and without heat release. Reductions in the skin-friction coefficient are observed in the exothermic case, compared to the isothermal one, and the underlying mechanism is explained. The absolute wall heat flux also increases, while the corresponding Nusselt number decreases with increasing heat release. Furthermore, the wall effects on the near-wall average burning rate are assessed. It is found that the isothermal cold wall results in an appreciable decrease of the burning rate in the exothermic cases. We observed indications that the wall increases the chances for the development of the premixed mode and its occurrence is very fast in the wall normal direction.
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| 19980. |
- Pouransari, Zeinab, 1982-
(författare)
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Fundamental studies of non-premixed combustion in turbulent wall jets using direct numerical simulation
- 2011
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The present thesis deals with the fundamental aspects of turbulent mixingand non-premixed combustion in wall-jet flows. Direct numerical simulations(DNS) of compressible turbulent flows are performed in a wall-jet configura-tion, which has a close resemblance to many industrial combustion applica-tions. The triple ”turbulence-chemistry-wall” interactions are also present inthis flow set-up. These interactions have been addressed by first focusing onturbulent flow effects on the isothermal reaction, including the near-wall issues.Then, by adding heat-release to the simulations, it has been concentrated onheat-release effects on various phenomena that occur in the reacting turbulentwall-jet flow. In the computational domain, fuel and oxidizer enter separatelyin a non-premixed manner and the flow is fully turbulent and subsonic in allsimulations. In the first phase of this study, the case of a turbulent wall-jetincluding an isothermal reaction without heat release is addressed in order toisolate the near-wall effects and the mixing characteristics of the flow and thekey statistics for combustion are studied in the absence of thermal effects. Adeeper insight into three-dimensional mixing and reaction characteristics in aturbulent wall-jet has been gained through investigation of the probability den-sity functions, higher order moments of velocities and reacting scalars and thescalar dissipation rates of different species. In the second phase, DNS of turbu-lent reacting wall-jets including heat release is performed, where a single-stepglobal exothermic reaction with an Arrhenius-type reaction rate is considered.The main target was to identify the heat-release effects on different mixingscales of turbulent wall-jet flow. The scalar dissipation rates, time scale ratios,two-point correlations, one and two-dimensional premultiplied spectra are usedto illustrate the heat release induced modifications. It is observed that heatrelease effects delay the transition process in the chemically reacting cases andenlarge the fluctuation intensities of density and pressure, but have a dampingeffect on all velocity fluctuation intensities. Finer small mixing scales were ob-served in the isothermal simulations and larger vortical structures formed afteradding significant amounts of heat-release. Simulations with different Damk ̈h- oler numbers, but comparable temperature-rise are performed and the expectedbehavior, a thinner flame with increasing Damk ̈hler number, is observed. Finally, some heat transfer related quantities are examined. The wall heat fluxand the corresponding Nusselt numbers are addressed. The near-wall reactioneffects on the skin friction coefficient are studied and further the reaction char-acteristics are investigated throughout the domain.
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