The Experts below are selected from a list of 164136 Experts worldwide ranked by ideXlab platform
Hesham A Rakha - One of the best experts on this subject based on the ideXlab platform.
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Fuel Consumption model for heavy duty diesel trucks model development and testing
Transportation Research Part D-transport and Environment, 2017Co-Authors: Jinghui Wang, Hesham A RakhaAbstract:Abstract A simple, efficient, and realistic Fuel Consumption model is essential to support the development of effective eco-freight strategies, including eco-routing and eco-driving systems. The majority of the existing heavy duty truck (HDT) Fuel Consumption models, however, would recommend that drivers accelerate at full throttle or brake at full braking to minimize their Fuel Consumption levels, which is obviously not realistic. To overcome this shortcoming, the paper applies the Virginia Tech Comprehensive Power-based Fuel Consumption Model (VT-CPFM) framework to develop a new model that is calibrated and validated using field data collected using a mobile emissions research laboratory (MERL). The results demonstrate that the model accurately predicts Fuel Consumption levels consistent with field observations and outperforms the comprehensive modal emissions model (CMEM) and the motor vehicle emissions simulator (MOVES) model. Using the model it is demonstrated that the optimum Fuel economy cruise speed ranges between 32 and 52 km/h with steeper roads and heavier trucks resulting in lower optimum cruise speeds. The results also demonstrate that the model generates accurate CO 2 emission estimates that are consistent with field measurements. Finally, the model can be easily calibrated using data collected using non-engine instrumentation (e.g. Global Positioning System) and readily implemented in traffic simulation software, smartphone applications and eco-freight programs.
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Fuel Consumption model for conventional diesel buses
Applied Energy, 2016Co-Authors: Jinghui Wang, Hesham A RakhaAbstract:Abstract Existing bus Fuel Consumption models produce a bang–bang type of control, implying that drivers would have to either accelerate at full throttle or brake at full braking in order to minimize their Fuel Consumption levels. This is obviously not correct. The paper is intended to enhance bus Fuel Consumption modeling by circumventing the bang–bang control problem using the Virginia Tech Comprehensive Power-based Fuel Consumption Model (VT-CPFM) framework. The model is calibrated for a series of diesel-powered buses using in-field second-by-second data because of a lack of publicly available bus Fuel economy data. The results reveal that the bus Fuel Consumption rate is concave as a function of vehicle power instead of convex, as was the case with light duty vehicles. The model is calibrated for an entire bus series and demonstrated to accurately capture the Fuel Consumption behavior of each individual bus within its series. Furthermore, the model estimates are demonstrated to be consistent with in-field measurements. The optimum Fuel economy cruising speeds range between 40 and 50 km/h, which is slightly lower than that for gasoline-powered light duty vehicles (60–80 km/h). Finally, the model is demonstrated to capture transient Fuel Consumption behavior better than the Motor Vehicle Emission Simulator (MOVES) and produces a better fit to field measurements compared to the Comprehensive Modal Emission Model (CMEM).
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assessment of alternative polynomial Fuel Consumption models for use in intelligent transportation systems applications
Journal of Intelligent Transportation Systems, 2013Co-Authors: Bart Saerens, Hesham A Rakha, Kyoungho Ahn, Eric Van Den BulckAbstract:The objective of this article is to identify appropriate low-degree polynomial Fuel Consumption models for use in intelligent transportation systems (ITSs), eco-drive assist systems, and microscopic traffic simulation software. The different models that are assessed include models found in the literature and new models developed using a subsearch regression based on the Akaike information criterion. The models are evaluated based on model structures and their effectiveness in predicting instantaneous vehicle Fuel Consumption levels. Measurement data obtained from an engine dynamometer, a chassis dynamometer, and on-road testing are used to conduct the study. The study demonstrates that several low-degree polynomial Fuel Consumption models with a quadratic control term are appropriate for use in ITS applications (R 2>0.9).
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virginia tech comprehensive power based Fuel Consumption model model development and testing
Transportation Research Part D-transport and Environment, 2011Co-Authors: Hesham A Rakha, Bart Saerens, Kevin Moran, Eric Van Den BulckAbstract:Abstract Existing automobile Fuel Consumption and emission models suffer from two major drawbacks; they produce a bang–bang control through the use of a linear power model and the calibration of model parameters is not possible using publicly available data thus necessitating in-laboratory or field data collection. This paper develops two Fuel Consumption models that overcome these two limitations. Specifically, the models do not produce a bang–bang control and are calibrated using US Environmental Protection Agency city and highway Fuel economy ratings in addition to publicly available vehicle and roadway pavement parameters. The models are demonstrated to estimate vehicle Fuel Consumption rates consistent with in-field measurements. In addition the models estimate CO2 emissions that are highly correlated with field measurements.
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estimating vehicle Fuel Consumption and emissions based on instantaneous speed and acceleration levels
Journal of Transportation Engineering-asce, 2002Co-Authors: Kyoungho Ahn, Hesham A Rakha, Antonio A Trani, Michel Van AerdeAbstract:Several hybrid regression models that predict hot stabilized vehicle Fuel Consumption and emission rates for light-duty vehicles and light-duty trucks are presented in this paper. Key input variables to these models are instantaneous vehicle speed and acceleration measurements. The energy and emission models described in this paper utilize data collected at the Oak Ridge National Laboratory (ORNL) that included Fuel Consumption and emission rate measurements (CO, HC, and NOx) for five light-duty vehicles and three light-duty trucks as a function of the vehicle’s instantaneous speed and acceleration levels. The Fuel Consumption and emission models are found to be highly accurate as compared to the ORNL data, with coefficients of determination ranging from 0.92 to 0.99. Given that the models utilize the vehicle’s instantaneous speed and acceleration levels as independent variables, these models are capable of evaluating the environmental impacts of operational-level projects including intelligent transporta...
Robert Van Den Brink - One of the best experts on this subject based on the ideXlab platform.
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why has car fleet specific Fuel Consumption not shown any decrease since 1990 quantitative analysis of dutch passenger car fleet specific Fuel Consumption
Transportation Research Part D-transport and Environment, 2001Co-Authors: Robert Van Den BrinkAbstract:The Dutch car-fleet specific Fuel Consumption has not shown any decrease since 1990. The main reasons for the car-fleet specific Fuel Consumption no longer showing a decrease after 1990, namely, increases in vehicle weight and cylinder capacity, have been concluded from an analysis of Dutch car-fleet specific Fuel Consumption in the period 1980–1997. The increase in weight of the average sales-weighted new car in this period can be almost completely explained by the increase in weight of successive models (upgrading). This upgrading is partly the result of competition between car manufacturers but is also due to stricter safety requirements. However, because upgrading has been fairly extreme, the 1981 model of a car type often belonged to a different car type than the 1997 model of the same type. Upgrading is therefore a consequence, not only of the competition among car manufacturers and stricter safety requirements, but probably also of the shift in consumer demand for more expensive, larger and heavier cars. The 1998 agreement with the European car manufacturers (ACEA) and the Dutch CO2 differentiation in car purchase taxes will probably lead to a further decrease in specific Fuel Consumption in the European Fuel test-cycle (Eurotest) in the near future. However, real-world specific Fuel Consumption will decrease less because the difference between specific Fuel Consumption measured in the Eurotest and real-world specific Fuel Consumption is expected to increase as a result of the increasing use of both air conditioners and direct-injection gasoline engines.
Zhiliang Yao - One of the best experts on this subject based on the ideXlab platform.
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vehicle technologies Fuel economy policies and Fuel Consumption rates of chinese vehicles
Energy Policy, 2012Co-Authors: Hong Huo, Michael Wang, Zhiliang YaoAbstract:Abstract One of the principal ways to reduce transport-related energy use is to reduce Fuel-Consumption rates of motor vehicles (usually measured in liters of Fuel per 100 km). Since 2004, China has implemented policies to improve vehicle technologies and lower the Fuel-Consumption rates of individual vehicles. Policy evaluation requires accurate and adequate information on vehicle Fuel-Consumption rates. However, such information, especially for Chinese vehicles under real-world operating conditions, is rarely available from official sources in China. For each vehicle type we first review the vehicle technologies and Fuel-economy policies currently in place in China and their impacts. We then derive real-world (or on-road) Fuel-Consumption rates on the basis of information collected from various sources. We estimate that the real-world Fuel-Consumption rates of vehicles in China sold in 2009 are 9 L/100 km for light-duty passenger vehicles, 11.4 L/100 km for light-duty trucks, 22 L/100 km for inter-city transport buses, 40 L/100 km for urban transit buses, and 24.9 L/100 km for heavy-duty trucks. These results aid in understanding the levels of Fuel Consumption of existing Chinese vehicle fleets and the effectiveness of policies in reducing on-road Fuel Consumption, which can help in designing and evaluating future vehicle energy-efficiency policies.
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Fuel Consumption rates of passenger cars in china labels versus real world
Energy Policy, 2011Co-Authors: Hong Huo, Zhiliang YaoAbstract:Recently, China has implemented many policy measures to control the oil demand of on-road vehicles. In 2010, China started to report the Fuel Consumption rates of light-duty vehicles tested in laboratory and to require new vehicles to show the rates on window labels. In this study, we examined the differences between the test and real-world Fuel Consumption of Chinese passenger cars by using the data reported by real-world drivers on the internet voluntarily. The sales-weighted average Fuel Consumption of new cars in China in 2009 was 7.80L/100km in laboratory and 9.02L/100km in real-world, representing a difference of 15.5%. For the 153 individual car models examined, the real-world Fuel Consumption rates were −8 to 60% different from the test values. The simulation results of the International Vehicle Emission model show that the real-world driving cycles in 22 selected Chinese cities could result in −8 to 34% of changes in Fuel Consumption compared to the laboratory driving cycle. Further government effort on Fuel Consumption estimates adjustment, local driving cycle development, and real-world data accumulation through communication with the public is needed to improve the accuracy of the labeling policy.
Tiago L Farias - One of the best experts on this subject based on the ideXlab platform.
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establishing bonds between vehicle certification data and real world vehicle Fuel Consumption a vehicle specific power approach
Energy Conversion and Management, 2015Co-Authors: Goncalo Duarte, Goncalo Goncalves, Patricia Baptista, Tiago L FariasAbstract:Abstract A method to perform the energy characterization of a vehicle according to the specific power required while driving was developed using public vehicle certification data. Using a portable emission measurement system, Fuel Consumption was quantified in a second-by-second basis under on-road conditions for 19 vehicles (spark-ignition, compression-ignition and hybrids). This data allowed building generic curves of Fuel Consumption as a function of the specific power, according to Vehicle Specific Power methodology. Comparing on-road measurements and the model estimates, a R2 higher than 0.9 for conventional and hybrid vehicles was obtained regarding modal Fuel Consumption. Comparing the Fuel Consumption measured on the drive cycles performed by each vehicle and the correspondent estimates, an absolute deviation of 9.2% ± 9.2% was found for conventional vehicles and 4.7% ± 1.8% for hybrids vehicles. This methodology was validated and applied to estimate the energy impacts of the best-selling vehicles in Portugal for different driving cycles. This prompt method, that does not require vehicle monitoring, can estimate curves of Fuel Consumption in g/s, as a function of specific power, which allows quantifying the absolute Fuel use for any driving cycle.
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comparing real world Fuel Consumption for diesel and hydrogen Fueled transit buses and implication for emissions
Transportation Research Part D-transport and Environment, 2007Co-Authors: Christopher H Frey, Nagui M Rouphail, Haibo Zhai, Tiago L Farias, G A GoncalvesAbstract:This paper explores the influence of key factors such as speed, acceleration, and road grade on Fuel Consumption for diesel and hydrogen Fuel cell buses under real-world operating conditions. A Vehicle Specific Power-based approach is used for modeling Fuel Consumption for both types of buses. To evaluate the robustness of the modeling approach, Vehicle Specific Power-based modal average Fuel Consumption rates are compared for diesel buses in the US and Portugal, and for the Portuguese diesel and hydrogen Fuel cell buses that operate on the same route. For diesel buses there is similar intra-vehicle variability in Fuel Consumption using Vehicle Specific Power modes. For the Fuel cell bus, the hydrogen Fuel Consumption rate was found to be less sensitive to Vehicle Specific Power variations and had smaller variability compared to diesel buses. Relative errors between trip Fuel Consumption estimates and actual Fuel use, based upon predictions for a portion of real-world activity data that were not used to calibrate the models, were generally under 10% for all observations. The Vehicle Specific Power-based modeling approach is recommended for further applications as additional data become available. Emission changes based upon substituting hydrogen versus diesel buses are evaluated.
Hong Huo - One of the best experts on this subject based on the ideXlab platform.
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vehicle technologies Fuel economy policies and Fuel Consumption rates of chinese vehicles
Energy Policy, 2012Co-Authors: Hong Huo, Michael Wang, Zhiliang YaoAbstract:Abstract One of the principal ways to reduce transport-related energy use is to reduce Fuel-Consumption rates of motor vehicles (usually measured in liters of Fuel per 100 km). Since 2004, China has implemented policies to improve vehicle technologies and lower the Fuel-Consumption rates of individual vehicles. Policy evaluation requires accurate and adequate information on vehicle Fuel-Consumption rates. However, such information, especially for Chinese vehicles under real-world operating conditions, is rarely available from official sources in China. For each vehicle type we first review the vehicle technologies and Fuel-economy policies currently in place in China and their impacts. We then derive real-world (or on-road) Fuel-Consumption rates on the basis of information collected from various sources. We estimate that the real-world Fuel-Consumption rates of vehicles in China sold in 2009 are 9 L/100 km for light-duty passenger vehicles, 11.4 L/100 km for light-duty trucks, 22 L/100 km for inter-city transport buses, 40 L/100 km for urban transit buses, and 24.9 L/100 km for heavy-duty trucks. These results aid in understanding the levels of Fuel Consumption of existing Chinese vehicle fleets and the effectiveness of policies in reducing on-road Fuel Consumption, which can help in designing and evaluating future vehicle energy-efficiency policies.
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Fuel Consumption rates of passenger cars in china labels versus real world
Energy Policy, 2011Co-Authors: Hong Huo, Zhiliang YaoAbstract:Recently, China has implemented many policy measures to control the oil demand of on-road vehicles. In 2010, China started to report the Fuel Consumption rates of light-duty vehicles tested in laboratory and to require new vehicles to show the rates on window labels. In this study, we examined the differences between the test and real-world Fuel Consumption of Chinese passenger cars by using the data reported by real-world drivers on the internet voluntarily. The sales-weighted average Fuel Consumption of new cars in China in 2009 was 7.80L/100km in laboratory and 9.02L/100km in real-world, representing a difference of 15.5%. For the 153 individual car models examined, the real-world Fuel Consumption rates were −8 to 60% different from the test values. The simulation results of the International Vehicle Emission model show that the real-world driving cycles in 22 selected Chinese cities could result in −8 to 34% of changes in Fuel Consumption compared to the laboratory driving cycle. Further government effort on Fuel Consumption estimates adjustment, local driving cycle development, and real-world data accumulation through communication with the public is needed to improve the accuracy of the labeling policy.
