Diesel-engined vehicle nitric oxide and soot emissions during the European light-duty driving cycle using a transient mapping approach

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.

Download Full-text

Analysis of emissions from various driving cycles based on real driving measurements obtained in a high-altitude city

Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering ◽

10.1177/0954407019898959 ◽

2020 ◽

Vol 234 (6) ◽

pp. 1563-1571 ◽

Cited By ~ 1

Author(s):

Meng Lyu ◽

Xiaofeng Bao ◽

Yunjing Wang ◽

Ronald Matthews

Keyword(s):

High Altitude ◽

Real World ◽

Vehicle Emissions ◽

Control Strategies ◽

Driving Cycle ◽

Specific Power ◽

Test Cycle ◽

Light Duty ◽

And Control ◽

Light Duty Vehicles

Vehicle emissions standards and regulations remain weak in high-altitude regions. In this study, vehicle emissions from both the New European Driving Cycle and the Worldwide harmonized Light-duty driving Test Cycle were analyzed by employing on-road test data collected from typical roads in a high-altitude city. On-road measurements were conducted on five light-duty vehicles using a portable emissions measurement system. The certification cycle parameters were synthesized from real-world driving data using the vehicle specific power methodology. The analysis revealed that under real-world driving conditions, all emissions were generally higher than the estimated values for both the New European Driving Cycle and Worldwide harmonized Light-duty driving Test Cycle. Concerning emissions standards, more CO, NOx, and hydrocarbons were emitted by China 3 vehicles than by China 4 vehicles, whereas the CO2 emissions exhibited interesting trends with vehicle displacement and emissions standards. These results have potential implications for policymakers in regard to vehicle emissions management and control strategies aimed at emissions reduction, fleet inspection, and maintenance programs.

Download Full-text

A Novel Fuel Performance Index for Low-Temperature Combustion Engines Based on Operating Envelopes in Light-Duty Driving Cycle Simulations

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4029948 ◽

2015 ◽

Vol 137 (10) ◽

Cited By ~ 7

Author(s):

Kyle E. Niemeyer ◽

Shane R. Daly ◽

William J. Cannella ◽

Christopher L. Hagen

Keyword(s):

Low Temperature ◽

Performance Index ◽

Test Procedure ◽

Driving Cycle ◽

Low Temperature Combustion ◽

Fuel Performance ◽

Light Duty ◽

Auto Ignition ◽

Temperature Combustion ◽

Light Duty Vehicle

Low-temperature combustion (LTC) engine concepts such as homogeneous charge compression ignition (HCCI) offer the potential of improved efficiency and reduced emissions of nitrogen oxide (NOx) and particulates. However, engines can only successfully operate in HCCI mode for limited operating ranges that vary depending on the fuel composition. Unfortunately, traditional ratings such as octane number (ON) poorly predict the auto-ignition behavior of fuels in such engine modes, and metrics recently proposed for HCCI engines have areas of improvement when wide ranges of fuels are considered. In this study, a new index for ranking fuel suitability for LTC engines was defined, based on the fraction of potential fuel savings achieved in the federal test procedure (FTP-75) light-duty vehicle driving cycle. Driving cycle simulations were performed using a typical light-duty passenger vehicle, providing pairs of engine speed and load points. Separately, single-zone naturally aspirated HCCI engine simulations were performed for a variety of fuels in order to determine the operating envelopes for each. These results were combined to determine the varying improvement in fuel economy offered by fuels, forming the basis for a fuel performance index. Results showed that, in general, lower octane fuels performed better, resulting in higher LTC fuel index values; however, ON alone did not predict fuel performance.

Download Full-text

Analysis of Emissions in the European Driving Cycle of Used Light-Duty Vehicles Imported to Europe from North America

SAE International Journal of Sustainable Transportation, Energy, Environment, & Policy ◽

10.4271/13-01-01-0001 ◽

2019 ◽

Vol 1 (1) ◽

Cited By ~ 3

Author(s):

Oleksiy Klymenko ◽

Viktor Ustymenko ◽

Kostiantyn Kolobov ◽

Sergiy Rychok ◽

Mykola Hora ◽

...

Keyword(s):

North America ◽

Driving Cycle ◽

Light Duty ◽

Light Duty Vehicles

Download Full-text

Statistical approach to identify Naples city’s real driving cycle referring to the Worldwide harmonized Light duty Test Cycle (WLTC) framework

Sustainable Development and Planning VIII ◽

10.2495/sdp160461 ◽

2016 ◽

Author(s):

L. Della Ragione ◽

G. Meccariello

Keyword(s):

Statistical Approach ◽

Driving Cycle ◽

Test Cycle ◽

Light Duty

Download Full-text

Investigation of the LTC fuel performance index for oxygenated reference fuel blends

10.31224/osf.io/f9tm8 ◽

2016 ◽

Author(s):

Kyle Evan Niemeyer ◽

Shane Daly ◽

William Cannella ◽

Christopher Hagen

Keyword(s):

Performance Index ◽

Engine Speed ◽

Driving Cycle ◽

Fuel Performance ◽

Fuel Blend ◽

Fuel Savings ◽

Fuel Blends ◽

Light Duty ◽

Octane Rating ◽

Light Duty Vehicle

A new metric for ranking the suitability of fuels in LTC engines was recently introduced, based on the fraction of potential fuel savings achieved in the FTP-75 light-duty vehicle driving cycle. In the current study, this LTC fuel performance index was calculated computationally and analyzed for a number of fuel blends comprised of n-heptane, isooctane, toluene, and ethanol in various combinations and ratios corresponding to octane numbers from 0 to 100. In order to calculate the LTC index for each fuel, computational driving cycle simulations were first performed using a typical light-duty passenger vehicle, providing pairs of engine speed and load points. Separately, for each fuel blend considered, single-zone naturally aspirated HCCI engine simulations with a compression ratio of 9.5 were performed in order to determine the operating envelopes. These results were combined to determine the varying improvement in fuel economy offered by fuels, forming the basis for the LTC fuel index. The resulting fuel performance indices ranged from 36.4 for neat n-heptane (PRF0) to 9.20 for a three-component blend of n-heptane, isooctane, and ethanol (ERF1). For the chosen engine and chosen conditions, in general lower-octane fuels performed better, resulting in higher LTC fuel index values; however, the fuel performance index correlated poorly with octane rating for less-reactive, higher-octane fuels.

Download Full-text

A Novel Fuel Performance Index for LTC Engines Based on Operating Envelopes in Light-Duty Driving Cycle Simulations

Volume 1: Large Bore Engines; Fuels; Advanced Combustion; Emissions Control Systems ◽

10.1115/icef2014-5478 ◽

2014 ◽

Cited By ~ 1

Author(s):

Kyle E. Niemeyer ◽

Shane R. Daly ◽

William J. Cannella ◽

Christopher L. Hagen

Keyword(s):

Performance Index ◽

Octane Number ◽

Driving Cycle ◽

Low Temperature Combustion ◽

Fuel Performance ◽

Fuel Savings ◽

Light Duty ◽

Hcci Engines ◽

Temperature Combustion ◽

Light Duty Vehicle

Low-temperature combustion (LTC) engine concepts such as homogeneous charge compression ignition (HCCI) offer the potential of improved efficiency and reduced emissions of NOx and particulates. However, engines can only successfully operate in HCCI mode for limited operating ranges that vary depending on the fuel composition. Unfortunately, traditional ratings such as octane number poorly predict the autoignition behavior of fuels in such engine modes, and metrics recently proposed for HCCI engines have areas of improvement when wide ranges of fuels are considered. In this study, a new index for ranking fuel suitability for LTC engines was defined, based on the fraction of potential fuel savings achieved in the FTP-75 light-duty vehicle driving cycle. Driving cycle simulations were performed using a typical light-duty passenger vehicle, providing pairs of engine speed and load points. Separately, single-zone naturally aspirated HCCI engine simulations were performed for a variety of fuels in order to determine the operating envelopes for each. These results were combined to determine the varying improvement in fuel economy offered by fuels, forming the basis for a fuel performance index. Results showed that, in general, lower octane fuels performed better, resulting in higher LTC fuel index values; however, octane number alone did not predict fuel performance.

Download Full-text