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[en] Past investigations have shown that the current type-approval test cycles are not representative for real-world vehicle usage. Consequently, the emissions and fuel consumption of the vehicles are underestimated. Therefore, a new cycle is being developed in the UNECE framework (World-harmonised Light-duty Test Procedure, WLTP), aiming at a more dynamic and worldwide harmonised test cycle. To provide recommendations for the new cycle, we have analysed the noxious emission results of a test programme of seven vehicles on the test cycles NEDC (New European Driving Cycle) and CADC (Common Artemis Driving Cycles). This paper presents the results of that analysis to show the zones of the cycle that are causing the highest emissions, using two different approaches. Both approaches show that the zones with the highest emissions of modern vehicles differ from vehicle to vehicle. Consequently, a representative test cycle has to contain as many combinations of vehicle speed and acceleration that occur in real-world traffic as possible to prevent that a vehicle does not perform well for certain combinations because they are not included in the test cycle. Furthermore, the paper demonstrates that it is important to include a cold start to ensure rapid warm up of the catalysts. - Highlights: ► Vehicle emissions on the NEDC and CADC type-approval cycles are analysed. ► The zones within the cycles that produce the highest emissions are investigated. ► It is shown that these zones can differ significantly from one vehicle to another. ► The WLTP cycle should contain as many of the real-world driving zones as possible.
[en] A common assumption in lifecycle assessment (LCA) based estimates of greenhouse gas (GHG) benefits (or costs) of renewable fuel such as biofuel is that it simply replaces an energy-equivalent amount of fossil fuel and that total fuel consumption remains unchanged. However, the adoption of renewable fuels will affect the price of fuel and therefore affect total fuel consumption which, may increase or decrease depending on the policy regime and market conditions. Using a representative two-region model of the global oil market in which, one region implements a domestic biofuel mandate and the other does not, we show that the net change in global fuel consumption due to the policy, which we term indirect fuel use change (IFUC), can have a significant impact on the net GHG emissions associated with biofuel. If LCA-based regulations are designed to account for indirect emissions such as indirect land use change, then we argue that IFUC emissions cannot be ignored. Our work also shows how different policies can affect the environmental impact from adopting a given clean technology differently. (author)
[en] There are many kinds of methods to estimate the energy requirement or fuel consumption in the optimal design and minimize the life cost of a building. The bin method is one of the most popular ways to estimate the energy performance of a building, which is based on the hourly-based outdoor dry-bulb temperatures of all days in a whole year. There is lack of information about the bin weather data in China. In this paper, the ambient temperature bin data for 26 cities in China are generated. Based on the method used in this paper, the bin data can be calculated with the long-term daily weather record or TMY weather data, the deviation between them is acceptable. The bin data given in this paper may have the positive impact on building energy conservation in China
[en] New fuel economy standards require new U.S. passenger vehicles to achieve at least 34.1 miles per gallon (MPG) on average by model year 2016, up from 28.8 MPG today. In this paper, the magnitude, combinations and timings of the changes required in U.S. vehicles that are necessary in order to meet the new standards, as well as a target of doubling the fuel economy within the next two decades are explored. Scenarios of future vehicle characteristics and sales mix indicate that the 2016 mandate is aggressive, requiring significant changes starting from today. New vehicles must forgo horsepower improvements, become lighter, and a greater number will use advanced, more fuel-efficient powertrains, such as smaller turbocharged engines, hybrid-electric drives. Achieving a factor-of-two increase in fuel economy by 2030 is also challenging, but more feasible since the auto industry will have more lead time to respond. A discussion on the feasibility of meeting the new fuel economy mandate is included, considering vehicle production planning realities and challenges in deploying new vehicle technologies into the market. (author)
[en] Highlights: • We conduct a natural field experiment on incentives for fuel-efficient driving. • A monetary and a tangible non-monetary reward for eco-driving are compared. • The non-monetary reward results in an average reduction of fuel consumption of 5%. • There is only a small reduction effect in the equivalent monetary reward treatment. • Emphasis of fun, emotional responses and frequency of recalling might play a role. - Abstract: Reducing greenhouse gas emissions is a highly prevalent goal of public policy in many countries around the world. Convincing people to drive more fuel-efficiently (“eco-driving”) can contribute substantially to this goal and is often an integral part of policy initiatives. However, there is a lack of scientific studies on the effects of individual monetary and non-monetary incentives for eco-driving, especially in organizational settings and with regards to demonstrating causality, e.g., by using controlled experiments. We address this gap with a six months long controlled natural field experiment and introduce a monetary and a non-monetary reward for eco-driving to drivers of light commercial vehicles in different branches of a logistics company. Our results show an average reduction of fuel consumption of 5% due to a tangible non-monetary reward and suggest only a small reduction of the average fuel consumption in the equivalent monetary reward treatment. We find indications that more emphasis on the fun of achieving a higher fuel efficiency, a more emotional response to non-monetary incentives, and a higher frequency of thinking and talking about non-monetary incentives might play a role in the stronger effect of the tangible non-monetary reward. Policy implications for private and public actors are discussed.
[en] Range extender is the core component of E-REV, its start-stop control determines the operation modes of vehicle. This paper based on a certain type of E-REV, researched constant power control strategy of range extender in extended-range model, to target range as constraint condition, combined with different driving cycle conditions, by correcting battery SOC for range extender start-stop moment, optimized the control strategy of range extender, and established the vehicle and range extender start-stop control simulation model. Selected NEDC and UDDS conditions simulation results show that: under certain target mileage, the range extender running time reduced by 37.2% and 28.2% in the NEDC condition, and running time UDDS conditions were reduced by 40.6% and 33.5% in the UDDS condition, reached the purpose of meeting the vehicle mileage and reducing consumption and emission. (paper)
[en] The prospect and likelihood of hydrogen replacing fossil fuels as the world's main energy source is discussed in the article. Countries well-endowed with renewable natural energy sources, such as hydroelectricity, geothermal energy and tidal power, could, it is argued, use this to split water into hydrogen and oxygen. Technologies to produce, transport, store and harness the hydrogen produced are currently being explored, and these are described briefly. Two approaches to converting the final stage of the hydrogen cycle into useful power, currently being researched, are mentioned, burning it in a modified engine or using it in a fuel cell. (UK)
[en] Morphing wings have a high potential for improving the performance and reducing the fuel consumption of modern aircraft. Thanks to its simplicity, the compliant belt-rib concept is regarded by the authors as a promising solution. Using the compliant rib designed by Hasse and Campanile as a starting point, a compliant morphing wing made of composite materials is designed. Innovative methods for optimal placing of the actuation and for the quantification of the morphing are used. The performance of the compliant morphing wing in terms of three-dimensional (3D) structural behaviour and aerodynamic properties, both two- and three-dimensional, is presented and discussed. The fundamental importance of considering 3D coupling effects in the determination of the performance of morphing aerofoils is shown. (paper)
[en] Using a unique database of end-user local energy data and the recently developed Autoregressive Distributed Lag (ARDL) bounds testing approach to cointegration, we estimate the long-run elasticities of the Namibian energy demand function at both aggregated level and by type of energy (electricity, petrol and diesel) for the period 1980-2002. Our main results show that energy consumption responds positively to changes in GDP and negatively to changes in energy price and air temperature. The differences in price elasticities across fuels uncovered by this study have significant implications for energy taxation by Namibian policy makers. We do not find any significant cross-price elasticities between different fuel types. (author)
[en] This paper proposes a haptic clutch driven gear shifting assistance device that can help when the driver shifts the gear of a transmission system. In order to achieve this goal, a magnetorheological (MR) fluid-based clutch is devised to be capable of the rotary motion of an accelerator pedal to which the MR clutch is integrated. The proposed MR clutch is then manufactured, and its transmission torque is experimentally evaluated according to the magnetic field intensity. The manufactured MR clutch is integrated with the accelerator pedal to transmit a haptic cue signal to the driver. The impending control issue is to cue the driver to shift the gear via the haptic force. Therefore, a gear-shifting decision algorithm is constructed by considering the vehicle engine speed concerned with engine combustion dynamics, vehicle dynamics and driving resistance. Then, the algorithm is integrated with a compensation strategy for attaining the desired haptic force. In this work, the compensator is also developed and implemented through the discrete version of the inverse hysteretic model. The control performances, such as the haptic force tracking responses and fuel consumption, are experimentally evaluated. (paper)