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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
161

Kraftstoffverbrauch durch Entnahme von Zapfluft und Wellenleistung von Strahltriebwerken

Ahlefelder, Sebastian January 2006 (has links) (PDF)
Zapfluft und Wellenleistung wird den Triebwerken entnommen, um die Energie für beispielsweise die Kraftstoffpumpen, das Inflight Entertainment oder die Flügelvorderkantenenteisung zu erzeugen. Diese Energiegenerierung, hat einen Anstieg des Kraftstoffverbrauches zur Folge. Es hat sich herausgestellt, dass die Stelle der Zapfluftentnahme einen starken Einfluss auf den Gradienten des Brennstoffverbrauches hat. Das Projekt beschäftigt sich mit zwei- und dreiwelligen Turbofantriebwerken und untersucht an ihnen, die Effekte der Leistungsnahmen. Als Simulationssoftware wurde GasTurb 8.0 eingesetzt und auf die integrierten Triebwerkskonfigurationen zurückgegriffen. Ziel der Arbeit ist die Ermittlung einer mathematischen Beziehung zur Berechnung des zusätzlichen Kraftstoffmassenstromes infolge einer Zapfluft- oder Wellenleistungsentnahme. So stellt sich die Frage, welche Triebwerksparameter dafür berücksichtigt werden müssen. Eine Wellenleistungsentnahme verursacht beispielsweise einen linearen Anstieg des spezifischen Kraftstoffverbrauches. Ist diese Zunahme, identisch mit der einer Zapfluftentnahme? Am Ende der Kapitel werden die Ergebnisse mit Literaturwerten verglichen und versucht Tendenzen zu erkennen bzw. bestehende zu erhärten.
162

Framtagande av lutningsföreteelse för ruttoptimering av bränsleförbrukning / Development of a slope phenomenon for route optimization of fuel consumption

Svalling, Patrik, Frogner, Lukas January 2022 (has links)
NVDB contains information of Sweden’s roads and a large number of properties concerning them. This information is provided as open data and is commonly usedin routing. For an optimal route optimization, several attributes are needed based on the road properties. At the time that this report was written, there was no attribute for slopes. The purpose of this report was, in collaboration with the Swedish transport Administration, to develop a new property “slope” for route optimization based on fuel consumption. The development of the slope phenomenon was built with FME where a script was created that calculated inclination on road links.The script calculated the inclination using a variation of the linear equation. Where x, y and z coordinates and attributes from NVDB were used to obtain values for the equation.The testing and validation of the generated slope property was performed with route optimization in the ArcMap application. The results from route optimization and previous research show a significant reduction in fuel consumption within routes with regard to slope. / NVDB innehåller information om Sveriges vägar och ett stort antal egenskaper för vägarna. Informationen tillhandahålls som öppen data och används ofta inom ruttning. För en optimal ruttoptimering behövs det ett flertal attribut baserat på vägegenskaper. Under tiden den här rapporten skapades så saknades det ett attribut för lutning. Syftet med den här rapporten var att i samarbete med Trafikverket ta fram en ny egenskap “lutning” vid ruttoptimering baserat på bränsleförbrukning. Framtagandet av lutningsföreteelsen var uppbyggt med hjälp av FME där ett skript skapades som beräknade lutningen i väglänkarna. §Skriptet beräknade lutning med hjälp av en variation av räta linjens ekvation. Därx, y och z koordinater samt attribut från NVDB användes för att få fram värden för ekvationen. Testandet och valideringen av den framtagna lutningsegenskapen framfördes med ruttoptimering i programmet ArcMap. Resultatet av ruttoptimeringen och tidigare forskning visar markant reduktion av bränsleförbrukning inom rutter med hänsyntill lutning.
163

A study of a feebate policy to reduce CO₂ emissions in the South African automotive industry

Du Plooy, Johann Leroux 03 1900 (has links)
Thesis (MAcc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Globally, climate change is probably the biggest environmental challenge facing the world this century. To accommodate change, the South African government introduced a vehicle emission tax on 1 September 2010. However, the design of the vehicle emission tax focuses on consumers and it might not be most effective in reducing CO2 emissions to the desired level. Therefore, alternative initiatives need to be identified and implemented to address increasing CO2 emissions. A “feebate” policy is considered as a possible alternative to reduce CO2 emissions. A literature review was performed on the topic of “feebate” policies and current tax legislation that could encourage vehicle manufacturers to invest in energy-efficient technology aimed at reducing CO2 emissions. Based on the literature review, a qualitative empirical study was conducted by means of a questionnaire, which was distributed to nine vehicle manufacturers in South Africa. The study specifically focused on vehicle manufacturers as they have the opportunity to design, develop and introduce energy-efficient technology, which could reduce CO2 emissions. Results suggest that a “feebate” policy that leads to costs savings should be considered by government to encourage vehicle manufacturers to invest in energy-efficient technology in order to lower CO2 emissions. It was also noted that, in general, the provisions of the current Income Tax Act No. 58 of 1962 provides little incentive to encourage vehicle manufacturers to invest in energy-efficient technologies to reduce CO₂ emissions. / AFRIKAANSE OPSOMMING: Wêreldwyd is klimaatverandering waarskynlik die grootste uitdaging wat die wêreld in die gesig staar die eeu. Die Suid-Afrikaanse regering het op 1 September 2010 ʼn voertuig uitlatingsbelasting ingestel om verandering te akkommodeer. Aangesien die ontwerp van voertuig uitlatingsbelasting egter fokus op die verbruiker, is dit moontlik nie die effektiefste manier om CO2-uitlatings te verminder en tot ʼn aanvaarbare vlak nie. Dus moet alternatiewe inisiatiewe geïdentifiseer en geïmplementeer word om toenemende CO2-uitlatings aan te spreek. ʼn “Feebate” beleid word oorweeg as ʼn moontlike alternatief om CO2-uitlatings te verminder. ʼn Literatuurstudie is uitgevoer rakende die onderwerp van “feebate” beleide en huidige belastingwetgewing wat voertuigvervaardigers kan motiveer om te investeer in energie effektiewe tegnologie wat gemik is daarop om CO2-uitlatings te beperk. Gebaseer op die literatuurstudie is ʼn kwalitatiewe empiriese studie uitgevoer deur middel van ʼn vraelys, wat aan al nege voertuigvervaardigers in Suid-Afrika gestuur is. Die studie het spesifiek op voertuigvervaardigers gefokus, omrede hulle die geleentheid het om energie effektiewe tegnologie te ontwerp, te ontwikkel en voor te stel wat CO2-uitlatings kan verminder. Resultate dui daarop dat die regering ʼn “feebate” beleid, wat sal lei tot kostebesparing, behoort te oorweeg om sodoende voertuigvervaardigers te motiveer om in energie effektiewe tegnologie te investeer om CO2-uitlatings te verlaag. Daar is ook bevind dat die huidige Inkomstebelastingwet No. 58 van 1962 oor die algemeen min insentief verskaf om voertuigvervaardigers te motiveer om in energie effektiewe tegnologie te investeer om CO2-uitlatings te verlaag.
164

A study on the efficiency and effectiveness of using alternative fuel vehicles to improve air quality in Hong Kong

Ho, Kwai-fung, Martha., 何桂鳳. January 2003 (has links)
published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management
165

Analysis of the performance of an optimization model for time-shiftable electrical load scheduling under uncertainty

Olabode, John A. 12 1900 (has links)
Approved for public release; distribution is unlimited / To ensure sufficient capacity to handle unexpected demands for electric power, decision makers often over-estimate expeditionary power requirements. Therefore, we often use limited resources inefficiently by purchasing more generators and investing in more renewable energy sources than needed to run power systems on the battlefield. Improvement of the efficiency of expeditionary power units requires better managing of load requirements on the power grids and, where possible, shifting those loads to a more economical time of day. We analyze the performance of a previously developed optimization model for scheduling time-shiftable electrical loads in an expeditionary power grids model in two experiments. One experiment uses model data similar to the original baseline data, in which expected demand and expected renewable production remain constant throughout the day. The second experiment introduces unscheduled demand and realistic fluctuations in the power production and the demand distributions data that more closely reflect actual data. Our major findings show energy grid power production composition affects which uncertain factor(s) influence fuel con-sumption, and uncertainty in the energy grid system does not always increase fuel consumption by a large amount. We also discover that the generators running the most do not always have the best load factor on the grid, even when optimally scheduled. / Lieutenant Commander, United States Navy
166

The energy consumption mechanisms of a power-split hybrid electric vehicle in real-world driving

Lintern, Matthew A. January 2015 (has links)
With increasing costs of fossil fuels and intensified environmental awareness, low carbon vehicles, including hybrid electric vehicles (HEVs), are becoming more popular for car buyers due to their lower running costs. HEVs are sensitive to the driving conditions under which they are used however, and real-world driving can be very different to the legislative test cycles. On the road there are higher speeds, faster accelerations and more changes in speed, plus additional factors that are not taken into account in laboratory tests, all leading to poorer fuel economy. Future trends in the automotive industry are predicted to include a large focus on increased hybridisation of passenger cars in the coming years, so this is an important current research area. The aims of this project were to determine the energy consumption of a HEV in real-world driving, and investigate the differences in this compared to other standard drive cycles, and also compared to testing in laboratory conditions. A second generation Toyota Prius equipped with a GPS (Global Positioning System) data logging system collected driving data while in use by Loughborough University Security over a period of 9 months. The journey data was used for the development of a drive cycle, the Loughborough University Urban Drive Cycle 2 (LUUDC2), representing urban driving around the university campus and local town roads. It will also have a likeness to other similar driving routines. Vehicle testing was carried out on a chassis dynamometer on the real-world LUUDC2 and other existing drive cycles for comparison, including ECE-15, UDDS (Urban Dynamometer Driving Schedule) and Artemis Urban. Comparisons were made between real-world driving test results and chassis dynamometer real-world cycle test results. Comparison was also made with a pure electric vehicle (EV) that was tested in a similar way. To verify the test results and investigate the energy consumption inside the system, a Prius model in Autonomie vehicle simulation software was used. There were two main areas of results outcomes; the first of which was higher fuel consumption on the LUUDC2 compared to other cycles due to cycle effects, with the former having greater accelerations and a more transient speed profile. In a drive cycle acceleration effect study, for the cycle with 80% higher average acceleration than the other the difference in fuel consumption was about 32%, of which around half of this was discovered to be as a result of an increased average acceleration and deceleration rate. Compared to the standard ECE-15 urban drive cycle, fuel consumption was 20% higher on the LUUDC2. The second main area of outcomes is the factors that give greater energy consumption in real-world driving compared to in a laboratory and in simulations being determined and quantified. There was found to be a significant difference in fuel consumption for the HEV of over a third between on-road real-world driving and chassis dynamometer testing on the developed real-world cycle. Contributors to the difference were identified and explored further to quantify their impact. Firstly, validation of the drive cycle accuracy by statistical comparison to the original dataset using acceleration magnitude distributions highlighted that the cycle could be better matched. Chassis dynamometer testing of a new refined cycle showed that this had a significant impact, contributing approximately 16% of the difference to the real-world driving, bringing this gap down to 21%. This showed how important accurate cycle production from the data set is to give a representative and meaningful output. Road gradient was investigated as a possible contributor to the difference. The Prius was driven on repeated circuits of the campus to produce a simplified real-world driving cycle that could be directly linked with the corresponding gradients, which were obtained by surveying the land. This cycle was run on the chassis dynamometer and Autonomie was also used to simulate driving this cycle with and without its gradients. This study showed that gradient had a negligible contribution to fuel consumption of the HEV in the case of a circular route where returning to the start point. A main factor in the difference to real-world driving was found to be the use of climate control auxiliaries with associated ambient temperature. Investigation found this element is estimated to contribute over 15% to the difference in real-world fuel consumption, by running the heater in low temperatures and the air conditioning in high temperatures. This leaves a 6% remainder made up of a collection of other small real-world factors. Equivalent tests carried out in simulations to those carried out on the chassis dynamometer gave 20% lower fuel consumption. This is accounted for by degradation of the test vehicle at approximately 7%, and the other part by inaccuracy of the simulation model. Laboratory testing of the high voltage battery pack found it constituted around 2% of the vehicle degradation factor, plus an additional 5% due to imbalance of the battery cell voltages, on top of the 7% stated above. From this investigation it can be concluded that the driving cycle and environment have a substantial impact of the energy use of a HEV. Therefore they could be better designed by incorporating real-world driving into the development process, for example by basing control strategies on real-world drive cycles. Vehicles would also benefit from being developed for use in a particular application to improve their fuel consumption. Alternatively, factors for each of the contributing elements of real-world driving could be included in published fuel economy figures to give prospective users more representative values.
167

Caractérisation expérimentale et modélisation numérique du comportement vibratoire des matériaux polymères chargés en fibres courtes : Application à un carter d’huile de Groupe Moto-Propulseur thermique d’automobiles / Experimental characterization and numerical modeling for the vibratory behavior of short fiber reinforced polymer materials : Application to an automotive powertrain oil pan

Zerrad, Mehdi 19 July 2018 (has links)
Les normes européennes d'émissions de CO2 étant de plus en plus contraignantes, les constructeurs automobiles cherchent, entre autres, à alléger leurs véhicules pour en diminuer la consommation. Ainsi, le remplacement des pièces métalliques par d'autres réalisées à partir de matériaux moins denses tels que les matériaux composites polymères chargés en fibres courtes est de plus en plus utilisé dans l'industrie automobile. Cependant, lors du processus de conception, les ingénieurs sont confrontés à des difficultés lors de la modélisation numérique de la réponse vibro-acoustique de ces pièces et/ou assemblages. En effet, ces matériaux sont très sensibles aux paramètres extérieurs tels que la température, la fréquence de sollicitation et l’humidité. De surcroît, leur comportement dépend également du procédé d’injection utilisé qui influe sur leur microstructure et plus particulièrement sur l’orientation et la dispersion des charges renforçantes. De fait, leur modélisation numérique est complexe et la confrontation aux mesures expérimentales non satisfaisante. Dans ce travail de recherche, l'influence des paramètres ambients sur le comportement dynamique d'un carter d'huile réalisé en polyamide 6 renforcé à 35\% en masse de fibres de verre a été étudiée. Les caractérisations mécaniques et microstructurales locales ont été effectuées afin d'investiguer les relations entre la microstructure et les propriétés de ces matériaux. Un modèle numérique a alors été développé sur la base de ces études expérimentales et a permis d’évaluer l'influence de la microstructure sur le comportement vibratoire d'un système modèle "plaque". Enfin, des corrélations calculs/essais ont été réalisées pour confronter la méthode de modélisation numérique aux mesures. Ces études ont permis de mettre en exergue la sensibilité de ces matériaux à leur environnement, d’établir une hiérarchisation de l'influence des différents paramètres sur leur comportement vibratoire et de proposer une méthodologie numérique basée sur la caractérisation expérimentale des éléments constitutifs pris séparément. / As European standards for CO2 emissions are becoming more stringent, car manufacturers are seeking, among other strategies, to lighten their vehicles to reduce their consumption. Thus, the replacement of metal parts by others made from lighter materials such as polymeric composite materials filled with short fibers is increasingly used in the automotive industry. However, during the design process, engineers face difficulties when trying to numerically model the vibro-acoustic response of these parts and / or assemblies. Indeed, these materials are very sensitive to external parameters such as temperature, loading frequency and humidity. In addition, their behavior also depends on the injection process which has an influence on their local microstructure and more particularly on the orientation and dispersion of the reinforcing fillers. In turn, their numerical modeling is complex and the comparison with the experimental measurements unsatisfactory. In this research work, the influence of the ambient parameters on the dynamic behavior of an oil pan made of polyamide 6 reinforced with 35\% by mass of glass fibers was studied. Local mechanical and microstructural characterizations were performed to investigate the relationship between the microstructure and the properties of these composite materials. A numerical model was then developed on the basis of these experimental studies and allowed to evaluate the influence of the microstructure on the vibratory behavior of a model plate system. Finally, computation / test correlations were performed to compare the numerical modeling method to the measurements. These studies have made it possible to highlight the sensitivity of these materials to their environment, to establish a hierarchy of the influence of the various parameters on their vibration behavior and to propose a "low cost" numerical methodology based on the experimental characterization of constituent elements taken separately.
168

Desenvolvimento de um modelo de mapa de consumo de combustível baseado em aquisição embarcadas. / Development of an internal combustion engine fuel map model based on on-board acquisition.

Steckelberg, Danilo Brito 01 November 2016 (has links)
É apresentada uma metodologia para descrever o mapa de desempenho (ou mapa de consumo de combustível) de um motor de combustão interna como função de suas condições de operação (rotação e torque) baseados em medições embarcadas. É utilizada para este levantamento a combinação de medições via GPS (para a velocidade longitudinal e inclinação de pista) e OBD-II para aquisição de sinais da rede CAN, como rotação do motor e consumo de combustível. É desenvolvida uma metodologia para o cálculo do torque líquido do motor baseado na medição de velocidade e aceleração longitudinal do veículo com uma margem de incerteza de 2% a 5% no cálculo do torque em condições normais de operações. É realizado um detalhamento da origem das incertezas para avaliar a contribuição individual de cada parâmetro. Um modelo de regressão polinomial é utilizado para descrever o mapa de consume de combustível do motor cujos coeficientes característicos são determinados experimentalmente através da metodologia proposta para cinco veículos diferentes a fim de comprovar a eficácia da metodologia. Os coeficientes de correlação variam de 0.797 a 0.997, sendo que em três de cinco veículos o coeficiente de correlação é maior que 0.910, comprovando a robustez da metodologia. / It is presented a methodology to describe the engine performance map (or the engine fuel map) for an internal combustion engine as a function of its operating conditions (engine speed and torque) based on on-board measurements. It is used a combination of GPS measurements for vehicle speed and road grade together with a OBD-II acquisition system in order to acquire information provided by CAN network, such as engine speed and fuel consumption. A methodology to calculate the engine torque based on speed and acceleration measurements is shown with an average uncertainty in the range of 2% to 5% for torque calculation in normal operating conditions. It is presented a detailed breakdown of the contribution of individual parameters in torque calculation uncertainty. A polynomial regression model to describe the engine fuel map is presented and the coefficients for this model is calculated based on on-road measurements for 5 different vehicles to prove the accuracy of the proposed methodology. The correlation coefficients obtained for these measurements are within the range of 0.797 to 0.997 and three out of five vehicles with correlation coefficient higher than 0.910, proving the methodology robust.
169

Desenvolvimento e aplicação de um modelo para o Pollution Routing Problem. / Developing and implementing a model for a Pollution Routing Problem.

Paschoal, Anderson Oliveira de Ornelas 27 April 2015 (has links)
O transporte rodoviário é uma das atividades econômicas do homem que mais contribuem para a emissão de Gases de Efeito Estufa (GEE) na atmosfera. Sabe-se que a emissão de CO2 está diretamente vinculada ao consumo de combustível. Por isso, é possível encontrar uma série de trabalhos que objetivam diminuir as emissões por meio da redução do consumo de combustível dos veículos. A otimização de rotas é uma importante ferramenta para essa redução e, consequentemente, possibilita minimizar as emissões dos veículos. Esta pesquisa tem como objetivo aplicar em uma empresa líder na distribuição de revistas no país o PRP, que é um modelo de minimização do consumo de combustível/emissão de GEE por meio de ajustes das variáveis como velocidade média, quantidade de carga transportada, distância percorrida e inclinações das vias. Como a maioria das metodologias de estimativa de combustível existentes na literatura não considera a inclinação das vias nos seus cálculos, neste trabalho foi necessário desenvolver uma metodologia para incluí-la no modelo. Testes foram efetuados com variações nas janelas de tempo, e o modelo mostrou-se sensível a cada uma das variáveis analisadas, gerando economias em 100% das rotas estudadas. / Road transport is one of the biggest contributors of Greenhouse Gases emissions of all humans economic activities. It is known that CO2 emissions are directly related to fuel consumption, so that is why it is possible to find a series of studies that aims to reduce emissions by reducing vehicles fuel consumption. Route optimization is an important tool for reducing fuel consumption and hence emissions. This research aims to implement the PRP model in a leading company in the country, which is a model that minimizes fuel consumption/GHG emissions through adjustments of variables such as average speed, pay load, distance traveled and slopes of the road. Most existing fuel estimation methodologies found in the literature does not consider the slope of the roads in their calculations. So in this research it was necessary to develop a methodology to include it in the model. Tests were performed with variations in the time windows and the model was sensitive to each of the variables analyzed, generating savings on 100% of the studied routes.
170

Vyhodnocení exploatačních parametrů vybraných pluhů v porovnatelných podmínkách

KUKLA, Martin January 2019 (has links)
In this diploma thesis, there are described different types of soil tillage and options of their use. The thesis focuses on comparision selected plow in comparable conditions. Plows were compared by efficiency, possibilities of the type of rotation on headlands, fuel consumption and durability of wearing parts. For measuring were chosen lands with a slope as small as possible and with furrow that should be as long as possible to minimize distortion of the results.

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