The pollution of the aviation industry is often identified as a main contributor toward climate change, justified by the immense amounts of greenhouse gasses emitted during a flight. Therefore, it is inevitable that the aviation industry acts toward decreasing emissions of flights for mitigation of the climate crisis. Altering the maneuvers by pilots can have an instant effect on emissions by optimizing fuel efficiency. This paper investigates the pilots’ perspectives on what opportunities and barriers there are to implement a self-assessment system for fuel efficiency in aviation. Furthermore, potential challenges that exist from an organizational point of view were studied. To answer the research questions, a case study approach was taken at a Scandinavian airline where thirteen pilots and other relevant stakeholders were interviewed, and literature review was established. The result was later analyzed using the Unified Technology Acceptance and Use model (UTAUT) and Diffusion of Innovation theory (DOI). The results show that pilots' generally have a positive attitude toward self-assessing fuel efficiency and find it interesting to see that their comprehension of what they do to be more fuel efficient concur with reality. Furthermore, they are positive toward any initiative that can increase their performance in safety or fuel use, since it was consistently stated that pilots are proud of their profession and want to improve if facts are presented. However, they want the interface to be concise with brief information with the possibility to go more in-depth if they feel the need to. As it is being launched, they want clear information regarding the software, it’s use and sufficient training in order to efficiently use it. The pilot barriers are that many senior pilots have been subjected to earlier implementations that have been bad in communication with insufficient information. In the discussion we propose that communication is key for a successful implementation along with a training session with the purpose of explaining the application and communicating possible benefits of using it. / Föroreningen från flygindustrin identifieras ofta som en stor bidragande effekt till klimatförändringar, motiverad av de stora mängder växthusgaser som släpps ut per person under en flygning. Det är därför oundvikligt att flygindustrin agerar för att minska utsläppen från flygoch ha en mindre påverkan på klimatförändringarna. Genom piloters manövrar kan man omedelbart påverka utsläppen genom att optimera bränsleeffektiviteten. Denna rapport undersöker piloternas perspektiv på vilka drivkrafter och motsättningar som finns för att införa ett själv-bedömande system för bränsleeffektivitet inom flygindustrin. Dessutom studerades potentiella utmaningar ur ett organisationsperspektiv. För att besvara forskningsfrågorna användes en fallstudie vid ett skandinaviskt flygbolag där tretton piloter och andra relevanta intressenter intervjuades och en litteraturstudie genomfördes. Resultatet analyserades senare med hjälp av Unified Technology Acceptance and Use Model (UTAUT) och Diffusion of Innovation Theory (DOI). Resultaten visar att piloter generellt har en positiv inställning till att själv utvärdera bränsleeffektiviteten och finner det intressant att se att deras uppfattning om hur de kan vara mer bränsleeffektiva överensstämmer med verkligheten. Dessutom är de positiva till alla initiativ som kan öka deras prestationer vad gäller säkerhet eller bränsleanvändning, eftersom det konsekvent framhölls att piloter är stolta över sitt yrke och vill förbättra sig om fakta presenteras. Dock vill de att gränssnittet ska vara koncist med kortfattad information och möjlighet att gå ner i djupet om de känner behov av det. Vid lansering önskar de tydlig information om programvaran, dess användning och tillräcklig utbildning för att kunna använda den effektivt. Piloternas hinder är att många äldre piloter har utsatts för tidigare implementationer som har brustit i kommunikationen med otillräcklig information. I diskussionen föreslår vi att kommunikation är nyckeln till en framgångsrik implementering, tillsammans med en utbildningssession med syfte att förklara applikationen och kommunicera fördelar med att använda den samt för att reda ut eventuella missuppfattningar.

Det finns ekonomiska, säkerhetsmässiga och miljömässiga vinster att göra genom att tillämpa ecodriving. Tidigare forskning pekar på att transportslagen bilar, tåg och flyg har gjort stora besparingar i ekonomiskt och miljömässigt hänseende, men hur ser det ut inom sjöfarten? Med denna frågeställning som bakgrund är syftet med studien att studera intresset för ecodriving bland svenska rederier och svenska myndigheter med en fartygsflotta. Dataunderlaget för studien utgörs av material från kvalitativa intervjuer med personer i exekutiv position. Resultatet av studien visar på att de flesta verksamheterna står i startgroparna eller redan arbetar utifrån en eller flera aktivt valda metoder för ecodriving. Resultatet visar också att det finns en blandning av förutsättningar och uppfattningar om vad ecodriving är och vad det kan bli inom sjöfarten. När frågor om automatisering i samband med ecodriving behandlas är resultatet tvetydigt. / There are economical, safetylike and environmental benefits of applying eco-driving. Previous research has shown that cars, trains and aviation have made significant savings economically and environmentaly speaking, but how does that transcend into the maritime business? With this question as a background, the aim with this thesis is to examine the interest of ecodriving among Swedish shipowners and authorities. The data in this thesis is derived from qualitative interviews with employees in executive land-based positions. The result shows that several of the shipowners and authorities are in the starting pits or are already conducting one or more eco-driving methods in their operations. The result also shows that there is a variety of prerequisites and perceptions of what eco-driving is and what is could become in the future among the respondents. When questions about automatization in relation to eco-driving are brought up, the result is ambiguous.

<div>The purpose of this dissertation is to study the effectiveness of public policies in generating fuel savings and emissions reductions. I focus on applying various empirical methods to analyze consumer responses to policy changes on both extensive and intensive margins. This dissertation consists of two chapters.</div><div><br></div><div>In the first chapter, I compare the effectiveness of fuel taxes and product taxes on reducing gasoline consumption of new car buyers. I employ a unified data source for vehicle choice and subsequent vehicle use to estimate a random effects logit demand model that explicitly accounts for vehicle use heterogeneity. My demand estimation suggests that new car buyers fully value the fuel-saving benefits from improved vehicle fuel efficiency when they initially purchase their cars. My policy simulations indicate that high-mileage drivers are more responsive to a change in fuel taxes than to a change in product taxes, even as low-mileage drivers are more responsive to product taxes. By capturing such heterogeneous consumer response to policies, I show that a counterfactual increase of the fuel tax is more effective than a revenue-equivalent product tax in reducing the total gasoline consumption of new car buyers. Further, when accounting for its effects on consumer response on both extensive and intensive margins, a change in fuel taxes has a clear advantage over a change in product taxes in reducing the consumption of gasoline even when the magnitude of tax increase is small. More importantly, a model not accounting for vehicle use heterogeneity understates the fuel saving effects of both policies and misleads us about the relative effectiveness when comparing different policies. </div><div><br></div><div>The second chapter explores how changes in the marginal cost of driving affect consumers decisions about passenger vehicle utilization, as measured by average daily miles traveled per vehicle. This intensive margin of consumer response has important implications for the effectiveness of usage-based policies, such as the fuel tax and the mileage tax, that designed to address externalities of driving. I estimate the elasticity of driving with respect to fuel cost per mile using a large panel data that covers 351 towns and cities in Massachusetts over 24 quarters. While most researchers in this literature apply fixed effects estimators to examine the elasticity of driving, I use a factor model econometric setup to account for unobserved common factors and regional heterogeneity. Residual diagnostics confirm that the factor model setup does a better job of removing the cross-section dependence than fixed effects estimators do. Given low consumer responsiveness to changes in the marginal cost of driving engendered by current usage-based policies, rights-based approaches like congestion charges might be better alternatives to influence vehicle utilization and vehicle ownership.</div>

The aim of this thesis is to give a perspective on the development of the Swedish automobility between 1950 and 2007. New knowledge on automobility’s role for economic historical development will be achieved by studying the interaction between the diffusion of the private car on the national and the regional level, and the households’ preferences and the government’s regulations of car ownership. The first paper, Two Sides of the Same Coin?, compares car diffusion in Norway and Sweden to find explanations for the national and regional patterns. We ask whether the slower diffusion in Norway can be explained with national differences in income, institutions, infrastructure and population settlements; or if regional differences in income and population density have affected the outcome? Our conclusion is that car diffusion in Norway and Sweden displays two sides of the same coin; the national levels converged, but the process did not follow the same regional pattern. Regional differences in income and population density have in general been a significant explanation for car density in Sweden, but not in Norway.   The second paper, Driving from the Centre to the Periphery?, examines whether the diffusion of private cars followed the over-all socio-economic and geographical changes in Sweden from 1960 to 1975. In particular, it studies if ownership per capita followed changes in income or changes in population density (urbanisation). The analysis is based on unique Swedish parish-scale census material that includes all private car owners for the years 1960, 1970 and 1975. Our conclusion is that income levels were more important than other explanations for the diffusion of private cars in Sweden between 1960 and 1975. The third paper, ‘En ledande och samordnande funktion’, contributes with new knowledge on how the Swedish government has organised traffic safety in certain ways since the 1950s. The emphasis is on the establishment and closing down of the National Road Safety Office (TSV) and how the changing forms of organisations before, during and after TSV have been reflected in the road plans from 1958, 1970 and 1990. Our conclusion is that the motives for both establishment and closing down of the TSV were the same; to create a more efficient organisation regarding traffic safety. These changes have been reflected in the road plans where an increased control over the infrastructure can be recognised, especially during the last two decades. The fourth paper, A Dark Side of Car Ownership, examines whether improved technical performance with respect to fuel consumption have been counterbalanced through increasing engine power and weight, how such properties are valued by the consumers, and in what way political instruments have affected this development. The analysis is based on historical data covering all car models within the 50 percentiles of new registrations. Our conclusion is that a vehicle purchase rebound effect can be identified since the fuel consumption has decreased over time, while the engine effect has increased. Also, the Swedish car fleet has developed in a setting of political instruments and regulations working in favour of larger and more fuel consuming cars.

Submitted by Marcia Silva (marcia@latec.uff.br) on 2016-06-13T18:54:00Z No. of bitstreams: 1 Dissert BERNARDO RAMOS DE ABREU.pdf: 2490234 bytes, checksum: bafd10530bf6f695279dc8f8a94ccb03 (MD5) / Made available in DSpace on 2016-06-13T18:54:00Z (GMT). No. of bitstreams: 1 Dissert BERNARDO RAMOS DE ABREU.pdf: 2490234 bytes, checksum: bafd10530bf6f695279dc8f8a94ccb03 (MD5) Previous issue date: 2013-12-16 / O objetivo deste trabalho é avaliar e quantificar o impacto do envelhecimento de frota no consumo de combustível e consequentemente na Eficiência Energética de uma empresa ferroviária de transporte de cargas. Verificou-se, por meio da pesquisa bibliográfica, que o Brasil apresenta padrões diferentes dos países considerados desenvolvidos no que diz respeito a qualidade da infraestrutura e a matriz de transporte. Esta situação impacta diretamente nos custos operacionais e consequentemente na competitividade dos produtos brasileiros nos mercados internos e externos. Parte deste elevado custo está relacionada ao consumo de combustível. Uma das soluções seria a expansão do transporte ferroviário, visto que é um modal que atende grandes distâncias e é mais eficiente energeticamente que o rodoviário. Este modal, após o processo de concessão, apresentou aumento do volume transportado, redução de acidentes e melhoria na eficiência energética. Mesmo com este cenário, a busca pela melhoria da eficiência energética é constante em empresas ferroviárias. Esta pesquisa evidenciou, estatisticamente, que o envelhecimento da frota eleva o consumo de combustíveis, em contrapartida, uma manutenção corretiva, apesar dos custos, beneficia a eficiência energética. / The goal of this study is to evaluate and quantify the aging fleet impact on fuel consumption and therefore on fuel efficiency of a freight railway. It was verified by a bibliographical research, that Brazil has a different standard from developed countries regarding infrastructure quality and the transport matrix. This condition has a direct impact on operational costs and consequently on the Brazilian products competitiveness in domestic and foreign markets. Part of this high cost is related to fuel consumption. One solution would be the development of the rail transportation, since it is a modal that work for large distances and is more energy efficient than road. This modal after the grant process, showed a growth in transported volume, accidents reduction and fuel efficiency enhancements. Even with this scenario, the seeking for best results on fuel efficiency is constant in railway companies. This research showed, statistically, that aging fleet increases fuel consumption, however, corrective maintenance, despite the costs, increase fuel efficiency.

In an effort to reduce harmful pollutants emitted by medium and heavy duty diesel engines, stringent emission regulations have been imposed by the Environmental Protection Agency (EPA) and the California Air Resources Board (CARB). Effective aftertreatment thermal management is critical for controlling tail pipe outlevels of NOx and soot, while improved fuel efficiency is also necessary to meet greenhouse gas emissions standards and customer expectations. Engine manufacturers have developed and implemented several engine and non-engine based techniques for emission reduction, a few examples being: exhaust gas recirculation (EGR), use of delayed in-cylinder injections, exhaust throttling, electric heaters and hydrocarbon dosers. This work elaborates the use of variable valve actuation strategies for improved aftertreatment system (ATS) thermal management of a modern medium-duty diesel engine while presenting opportunities for simplification of engine air handling architecture.<div><br></div><div>Experimental results at curb idle demonstrate that exhaust valve profile modulation enables effective ATS warm-up without requiring exhaust manifold pressure (EMP) control. Early exhaust valve opening with internal exhaust gas recirculation (EEVO+iEGR) resulted in 8% lower fuel consumption and reduction in engine out emissions. Late exhaust valve opening with internal EGR in the absence of EMP control was able to reach exhaust temperature of 287^◦C, without a penalty in fuel consumption or emissions compared to conventional thermal management. LEVO combined with EMP control could reach turbine outlet temperature of nearly 460^◦C at curb idle.<br></div><div><br></div><div>LEVO was studied at higher speeds and loads to assess thermal management benefits of LEVO in the absence of EMP control, with an observation that LEVO can maintain desirable thermal management performance up to certain speed/load conditions, and reduction in exhaust flow rate is observed at higher loads due to the inability of LEVO to compensate for loss of boost associated with absence of EMP control.<br></div><div><br></div><div>Cylinder deactivation (CDA) combined with additional valvetrain flexibility results in low emission, fuel-efficient solutions to maintain temperatures of a warmed-up ATS. Late intake valve closing, internal EGR and early exhaust valve opening were studied with both three cylinder and two cylinder operation. Some of these strategies showed additional benefits such as ability to use earlier injections, elimination of external EGR and operation in the absence of exhaust manifold pressure control. Three cylinder operation with LIVC and iEGR is capable of reaching exhaust temperatures in excess of 230^◦C with atleast 9% lower fuel consumption than three cylinder operation without VVA. Three cylinder operation with early exhaust valve opening resulted in exhaust temperature of nearly 340^◦C, suitable for extended idling operation. Two cylinder operation with and without the use of valve train flexibility also resulted in turbine outlet temperature relevant for extended idling (and low load operation), while reducing fuel consumption by 40% compared to the conventional thermal management strategy.<br></div><div><br></div><div>A study comparing the relative merits of internal EGR via reinduction and negative valve overlap (NVO) is presented in order to assess trade-offs between fuel efficient stay-warm operation and engine out emissions. This study develops an understanding of the optimal valve profiles for achieving reinduction/NVO and presents VVA strategies that are not cylinder deactivation based for fuel efficient stay-warm operation. Internal EGR via reinduction is demonstrated to be a more fuel efficient strategy for ATS stay-warm. An analysis of in-cylinder content shows that NOx emissions are more strongly affected by in-cylinder O2 content than by method of internal EGR.<br></div>

Die Arbeit widmet sich der Einsatzplanung von Luftfahrzeugen (LFZ) und fokussiert dabei auf die herausfordernde Thematik des Verschleißes, der zu einer Heterogenität in der Brennstoffeffizienz innerhalb der Flotte führt. Dieser heterogene Effekt wird durch den sogenannten 'Performance Factor' (PF) quantifiziert, der den Verbrauch im Vergleich zu einem nicht verschleißbehafteten Referenz-LFZ adjustiert. Trotz der nachgewiesenen Auswirkungen auf die Effizienz wird der PF bisher in der Einsatzplanung weitgehend vernachlässigt. Das Ziel dieser Forschungsarbeit besteht in der systematischen Untersuchung des Potenzials zur Reduzierung des Brennstoffbedarfs und der damit verbundenen CO2-Emissionen durch eine effizienzorientierte Einsatzplanung mittels Berücksichtigung des PF. Zu diesem Zweck wird ein taktisches Modell, das sogenannte 'TARP-Modell,' entwickelt. Es ermöglicht eine integrierte Lösung der Phasen des Aircraft Routings und des Tail Assignments, wodurch individuelle Flugdurchführungskosten unter Berücksichtigung der Heterogenität der Flüge und der PF-Verteilung in der Flotte ermittelt werden können. Die erzielten Ergebnisse verdeutlichen, dass eine effizienzorientierte Einsatzplanung eine Senkung der Brennstoffkosten um etwa 0,25% bis 0,5% ermöglicht. Selbst bei unvorhergesehenen Flugplanstörungen und der vermehrten Nutzung von sogenannten Aircraft Swaps (TARP-R-Modell) bleibt das Potenzial weitestgehend erhalten, sofern der PF angemessen in die Entscheidungsfindung integriert wird. Es ist jedoch zu beachten, dass das Potenzial mit zunehmender Komplexität in der Flug- und LFZ-Zuordnung durch verstärkte Restriktionen abnehmen kann. Die vorliegende Arbeit leistet somit einen Beitrag zur Ressourcenschonung und zur Verringerung der Klimawirksamkeit des Luftverkehrs. Es ist anzunehmen, dass zukünftige technologische Fortschritte im Bereich des digitalen Zwillings die Berechnung des PF noch präziser gestalten werden, wodurch dessen Bedeutung sowohl wissenschaftlich als auch operationell weiter an Bedeutung gewinnen dürfte. / The thesis is dedicated to the aircraft rotation and assignment and focuses on the challenging issue of aircraft performance degradation, which leads to heterogeneity in fuel efficiency within the fleet. This heterogeneous effect is quantified by the so-called 'Performance Factor' (PF), which adjusts fuel consumption in comparison to a non-worn reference aircraft. Despite its proven impact on efficiency, the PF has largely been disregarded in aircraft planning practices. The main objective of this research is to systematically investigate the potential for reducing fuel consumption and associated CO2 emissions through an efficiency-oriented aircraft planning approach, incorporating consideration of the PF. To achieve this goal, a tactical model, referred to as the 'TARP model,' is developed. The model facilitates an integrated solution to the aircraft routing and tail assignment phases, enabling the determination of individual flight execution costs while accounting for the heterogeneity of flights and PF distribution in the fleet. The results obtained underscore that an efficiency-oriented aircraft planning approach can yield a reduction in fuel costs of approximately 0.25% to 0.5%. Even in the presence of unforeseen flight schedule disruptions and increased utilization of aircraft swaps (TARP-R model), the potential remains largely preserved, provided the PF is adequately integrated into the decision-making process. Nevertheless, it should be noted that the potential may diminish with growing complexity in flight and aircraft assignment, stemming from heightened restrictions. Consequently, this study contributes to resource conservation and the mitigation of the aviation industry's climate impact. Anticipated advancements in digital twin technologies are expected to further refine PF calculations, enhancing its significance both from a scientific and operational standpoint.

Rising fuel cost has motivated increased fuel efficiency for freight trains. At cruising speed,the largest contributing factor to the fuel consumption is aerodynamic drag. As a result of stagnationand flow separation on and around lead and trailing cars, the first and last railcars experiencegreater drag than intermediate cars. Accordingly, this work focused on reducing drag on lead locomotivesby designing and optimizing an add-on nose fairing that is feasible for industrial operation.The fairing shape design was performed via computational fluid dynamic (CFD) software.The simulations consisted of two in-line freight locomotives, a stretch of rails on a raised subgrade,a computational domain, and a unique fairing geometry that was attached to the lead locomotive ineach non-baseline case. Relative motion was simulated by fixing the train and translating the rails,subgrade, and ground at a constant velocity. An equivalent uniform inlet velocity was applied atzero degree yaw to simulate relative motion between the air and the train.Five fairing families-Fairing Families A-E (FFA-FFE)-are presented in this thesis.Multidimensional regressions are created for each family to approximate drag as a function ofthe design variables. Thus, railroad companies may choose an alternative fairing if the recommendedfairing does not meet their needs and still have a performance estimate. The regression forFFE is used as a surrogate model in a surrogate based optimization. Results from a wind tunneltest and from CFD are reported on an FFE geometry to validate the CFD model. The wind tunneltest predicts a nominal drag reduction of 16%, and the CFD model predicts a reduction of 17%.A qualitative analysis is performed on the simulations containing the baseline locomotive, the optimalfairings from FFA-FFC, and the hybrid child and parent geometries from FFA & FFC. Theanalysis reveals that optimal performance is achieved for a narrow geometry from FFC becausesuction behind the fairing is greatly reduced. Similarly, the analysis reveals that concave geometriesboost the flow over the top leading edge of the locomotive, thus eliminating a vortex upstreamof the windshields. As a result, concave geometries yield greater reductions in drag.The design variable definitions for each family were strategically selected to improve manufacturability,operational safety, and aerodynamic performance relative to the previous families.As a result, the optimal geometry from FFE is believed to most completely satisfy the constraintsof the design problem and should be given the most consideration for application in the railroadindustry. The CFD solution for this particular geometry suggests a nominal drag reduction of 17%on the lead locomotive in an industrial freight train.

No description available.

Recently, based on the physics of viscosity, we developed a new technology, which utilizes electric or magnetic fields to change the rheology of complex fluids to reduce the viscosity, while keeping the temperature unchanged. The method is universal and applicable to all complex fluids with suspended particles of nano-meter, sub-micrometer, or micrometer size. Completely different from the traditional viscosity reduction method, raising the temperature, this technology is energy-efficient, as it only requires small amount of energy to aggregate the suspended particles. In this thesis, we will first discuss this new technology in detail, both in theory and practice. Then, we will report applications of our technology to energy science research. Presently, 80% of all energy sources are liquid fuels. The viscosity of liquid fuels plays an important role in energy production and energy conservation. With an electric field, we can reduce the viscosity of asphalt-based crude oil. This is important and useful for heavy crude oil and off-shore crude oil production and transportation. Especially, since there is no practical way to raise the temperature of crude oil inside the deepwater pipelines, our technology may play a key role in future off-shore crude oil production. Electrorehology can also be used to reduce the viscosity of refinery fuels, such as diesel fuel and gasoline. When we apply this technology to fuel injection, the fuel droplets in the fuel atomization become smaller, leading to faster combustion in the engine chambers. As the fuel efficiency of internal combustion engines depends on the combustion speed and timing, the fast combustion produces much higher fuel efficiency. Therefore, adding our technology on existing engines improves the engine efficiency significantly. A theoretical model for the engine combustion, which explains how fast combustion improves the engine efficiency, is also presented in the thesis. / Physics