The Effect of Driving Conditions and Ambient Temperature on Light Duty Gasoline-Electric Hybrid Vehicles (2): Fuel Consumption and Gaseous Pollutant Emission Rates

Author(s):  
Martha Christenson ◽  
Aaron Loiselle ◽  
Deniz Karman ◽  
Lisa A. Graham
Author(s):  
Jakub Lasocki

The World-wide harmonised Light-duty Test Cycle (WLTC) was developed internationally for the determination of pollutant emission and fuel consumption from combustion engines of light-duty vehicles. It replaced the New European Driving Cycle (NEDC) used in the European Union (EU) for type-approval testing purposes. This paper presents an extensive comparison of the WLTC and NEDC. The main specifications of both driving cycles are provided, and their advantages and limitations are analysed. The WLTC, compared to the NEDC, is more dynamic, covers a broader spectrum of engine working states and is more realistic in simulating typical real-world driving conditions. The expected impact of the WLTC on vehicle engine performance characteristics is discussed. It is further illustrated by a case study on two light-duty vehicles tested in the WLTC and NEDC. Findings from the investigation demonstrated that the driving cycle has a strong impact on the performance characteristics of the vehicle combustion engine. For the vehicles tested, the average engine speed, engine torque and fuel flow rate measured over the WLTC are higher than those measured over the NEDC. The opposite trend is observed in terms of fuel economy (expressed in l/100 km); the first vehicle achieved a 9% reduction, while the second – a 3% increase when switching from NEDC to WLTC. Several factors potentially contributing to this discrepancy have been pointed out. The implementation of the WLTC in the EU will force vehicle manufacturers to optimise engine control strategy according to the operating range of the new driving cycle.


2019 ◽  
Vol 100 ◽  
pp. 00043 ◽  
Author(s):  
Jakub Lasocki ◽  
Karol Boguszewski

From an environmental point of view, the fuel consumption of vehicles with combustion engines is directly related to the depletion of non-renewable crude oil resources and pollutant emission. The aim of this paper is to evaluate the effect of driving style on fuel consumption of light-duty vehicles. The study considered five metrics used for quantitative description of driving style: Dynamic Performance Index (DPI), Aggressiveness Factor (AF), Vehicle Aggressivity (VA), Total Aggressivity (TA), based upon the previous works of other researchers, and a newly proposed metric named Driving Style Indicator (DSI). All metrics were applied to the results of chassis dynamometer tests of two light-duty vehicles with spark-ignition and compression-ignition combustion engines. The values of metrics were plotted against corresponding values of fuel consumption to create dependences. Their analysis revealed that AF metric has strong correlation with fuel consumption, but is mathematically complex and requires numerous input data. DSI metric has simple mathematical form and is based only on the speed profile of the vehicle, and yet is characterized by a strong correlation with fuel consumption. DSI metric was further employed to investigate the influence of driving style on greenhouse gas (GHG) emissions from the Well-to-Wheel (WtW) perspective.


2018 ◽  
Vol 20 (8-9) ◽  
pp. 877-888 ◽  
Author(s):  
José Manuel Luján ◽  
Héctor Climent ◽  
Santiago Ruiz ◽  
Ausias Moratal

The effect of low ambient temperature on diesel raw pollutant emissions is analysed in two different driving cycles: NEDC and WLTC. The study is focused on hydrocarbons, carbon monoxide, nitrogen oxides and fuel consumption. Tests are conducted at cold start in a HSDI light-duty diesel engine with two levels of ambient temperature: 20 °C and −7 °C. Results showed a general detriment of pollutant emissions and break thermal efficiency at low ambient temperatures. NOx is increased around 250% in both cycles when running at low temperatures. Effect on hydrocarbons is more noticeable in the NEDC, where it rises in 270%, compared with the 150% of increase in the WLTC. In the case of carbon monoxide, uncorrelated tendencies are observed between both driving cycles. Concerning the NEDC, carbon monoxide emissions increase up to 125%, while at the WLTC, they are reduced up to 20%. Finally, from the point of view of the thermal efficiency, a reduction of nearly 10% in the NEDC is observed. However, no fuel penalty is spotted regarding the WLTC.


2021 ◽  
Vol 268 ◽  
pp. 01052
Author(s):  
Guangyao Wang ◽  
Hongyu Qin ◽  
Deyu Meng ◽  
Ziye Wang

Basing on the experimental study of fuel consumbtion in World-wide Harmonized Light-duty Test Cycle (WLTC ), this paper conducted the effects of using different immersion temperature on the fuel consumption of a light-duty gasoline vehicle. The study mainly studied the first phase of WLTC with three gaseous pollutant emissions: carbon dioxide, carbon monoxide and unburned hydrocarbon(CO2, CO and HC )which is measured to caculate the fuel consumption of Light-duty Gasoline Vehicles. It appears that with the increase of time the working condition of the vehicle tends to be stable resulting in the similar emission of the gaseous pollutant in the different test. Which means the immersion temperature mainly effects gaseous pollutant emissions in low-speed phase in WLTC. Besides, the cold start of engine had generated a large quantity of carbon monoxide and unburned hydrocarbon, but it is different for the carbon dioxide which was generated continuously in the first whole phase. The study also found that the use of a higher immersion temperatures (26℃) is more favorable than a lower immersion temperatures (23℃) in the typy of testing vehicle’s fuel consumption in the WLTC test cycle.


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