Harmful exhaust components and particles mass and number emission during the actual drive of a passenger car in accordance with the RDE procedure

The article presents toxic exhaust components emission measurement results as well as solid particles mass and number. The test involved a direct gasoline injection engine, in which special attention should be paid to the particulates number emission. Small diameters of nanoparticles make them particularly dangerous to human health. Nowadays, vehicle engines are constantly improved and modernized as a result of the need to meet existing exhaust gas emission standards. One of the few ways to determine the actual content of toxic and harmful compounds in the exhaust gases is the RDE (Real Driving Emissions) procedure, the requirements of which apply from 2016 for new vehicles, and from 2019 will apply to all registered passenger cars. The RDE procedure does not replace the WLTP (World Light-Duty Vehicle Test Procedure), but complements it. The tests on the dynamometer are separated from external conditions such as traffic volume or congestion and are not a sufficient indicator of emissions in real traffic conditions.

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Real Driving Emission Calibration—Review of Current Validation Methods against the Background of Future Emission Legislation

Applied Sciences ◽

10.3390/app11125429 ◽

2021 ◽

Vol 11 (12) ◽

pp. 5429

Author(s):

Johannes Claßen ◽

Sascha Krysmon ◽

Frank Dorscheidt ◽

Stefan Sterlepper ◽

Stefan Pischinger

Keyword(s):

Boundary Conditions ◽

Internal Combustion Engines ◽

Test Procedure ◽

Solid Particles ◽

Pollutant Emission ◽

Emission Measurement ◽

Chassis Dynamometer ◽

Limit Values ◽

Real Driving Emission ◽

Light Duty Vehicle

Reducing air pollution caused by emissions from road traffic, especially in urban areas, is an important goal of legislators and the automotive industry. The introduction of so-called “Real Driving Emission” (RDE) tests for the homologation of vehicles with internal combustion engines according to the EU6d legislation was a fundamental milestone for vehicle and powertrain development. Due to the introduction of non-reproducible on-road emission tests with “Portable Emission Measurement Systems” (PEMS) in addition to the standardized emission tests on chassis dynamometers, emission aftertreatment development and validation has become significantly more complex. For explicit proof of compliance with the emission and fuel consumption regulations, the legislators continue to require the “Worldwide Harmonized Light Duty Vehicle Test Cycle” (WLTC) on a chassis dynamometer. For calibration purposes, also various RDE profiles are conducted on the chassis dynamometer. However, the combination of precisely defined driving profiles on the chassis dynamometer and the dynamics-limiting boundary conditions in PEMS tests on the road still lead to discrepancies between the certified test results and the real vehicle behavior. The expected future emissions standards to replace EU6d will therefore force even more realistic RDE tests. This is to be achieved by significantly extending the permissible RDE test boundary conditions, such as giving more weight to the urban section of an RDE test. In addition, the introduction of limit values for previously unregulated pollutants such as nitrogen dioxide (NO2), nitrous oxide (N2O), ammonia (NH3) and formaldehyde (CH2O) is being considered. Furthermore, the particle number (for diameters of solid particles > 10 nm: PN10), the methane (CH4) emissions and emissions of non-methane organic gases (NMOG) shall be limited and must be tested. To simplify the test procedure in the long term, the abandonment of predefined chassis dyno emission tests to determine the pollutant emission behavior is under discussion. Against this background, current testing, validation, and development methods are reviewed in this paper. New challenges and necessary adaptations of current approaches are discussed and presented to illustrate the need to consider future regulatory requirements in today’s approaches. Conclusions are drawn and suggestions for a robust RDE validation procedure are formulated.

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Inspection of PN, CO2, and Regulated Gaseous Emissions Characteristics from a GDI Vehicle under Various Real-World Vehicle Test Modes

Energies ◽

10.3390/en13102581 ◽

2020 ◽

Vol 13 (10) ◽

pp. 2581

Author(s):

Kangjin Kim ◽

Wonyong Chung ◽

Myungsoo Kim ◽

Charyung Kim ◽

Cha-Lee Myung ◽

...

Keyword(s):

Real World ◽

High Speed ◽

Test Procedure ◽

Environmental Research ◽

Particulate Emissions ◽

Gaseous Emissions ◽

Tire Pressure ◽

Experimental Conditions ◽

Light Duty Vehicle ◽

Vehicle Test

Although the chassis dynamometer type approval test considers real-world conditions, there are a few limitations to the experimental test environment that may affect gaseous or particulate emissions such as road conditions, traffic, decreasing tire pressure, or fluctuating ambient temperature. Furthermore, the real driving emission (RDE) test takes a long time, and it is too long to repeat under different experimental conditions. The National Institute of Environmental Research (NIER) test modes that reflect the driving pattern of Korea are not certification test modes, but can be used to evaluate the influence of traffic conditions because these modes consist of a total of 15 test modes that vary according to average speed. The use of the NIER #03, #09, and #13 modes as low-, medium-, and high-speed modes allow for gaseous and particulate emissions to be measured and analyzed. Additionally, the worldwide harmonized light-duty vehicle test procedure (WLTP), the certification mode of Europe, is used to test cycles to investigate the difference under cold- and hot-engine start conditions. The engine operating parameters are also measured to evaluate the relationships between the various test conditions and test cycles. The regulated and greenhouse gas levels decrease under various driving conditions, but the particle number (PN) emission level shows a different trend with gaseous emissions. While the PN and CO2 results dramatically increase when the air conditioner is on, tire pressure conditions show different PN size distributions: a large-sized PN fraction, which contains particles larger than 100 nm, increases and a sub-23 nm-sized PN fraction decreases. Under cold-start conditions in the WLTP modes, there are much higher PN emissions than that of an engine under hot-start conditions, and the sub-23-nm-sized PN fraction also increases.

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Comparative Analysis of China Light-duty Vehicle Test cycle for Passenger Car and Other Typical Driving Cycles

E3S Web of Conferences ◽

10.1051/e3sconf/202124102002 ◽

2021 ◽

Vol 241 ◽

pp. 02002

Author(s):

Yu Liu ◽

Yongkai Liang ◽

Hanzhengnan Yu ◽

Xiaopan An ◽

Jingyuan Li

Keyword(s):

Automobile Industry ◽

Driving Cycle ◽

Third Party ◽

National Standard ◽

Test Cycle ◽

Passenger Cars ◽

Passenger Car ◽

Light Duty ◽

Light Duty Vehicle ◽

Vehicle Test

In 2019, China issued the first national standard for vehicle driving cycle, in which China light-duty vehicle test cycle for passenger car (CLTC-P) is the driving cycle for light-duty passenger cars. CLTC-P is of great significance to the development of China’s automobile industry, and has a great impact on the development and calibration of vehicles of automobile enterprises. In this paper, firstly, the driving characteristics of CLTC-P are analyzed systematically. Then it is compared with the third-party navigation big data to prove the rationality and effectiveness. Finally, CLTC-P is compared with other legal cycles in terms of time, distance, speed, and acceleration characteristics. The result shows that by comparing the characteristics of CLTC-P with other typical cycles and the GIS weighted results, the CLTC-P is more in line with Chinese reality and is significantly different from other typical cycles.

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Effects of the Particulate Matter Index and Particulate Evaluation Index of the Primary Reference Fuel on Particulate Emissions from Gasoline Direct Injection Vehicles

Atmosphere ◽

10.3390/atmos10030111 ◽

2019 ◽

Vol 10 (3) ◽

pp. 111 ◽

Cited By ~ 1

Author(s):

Yaowei Zhao ◽

Xinghu Li ◽

Shouxin Hu ◽

Chenfei Ma

Keyword(s):

Particulate Matter ◽

Direct Injection ◽

Test Procedure ◽

Gasoline Direct Injection ◽

Evaluation Index ◽

Particulate Emissions ◽

Passenger Cars ◽

Primary Reference ◽

Light Duty Vehicle ◽

Particulate Number

The purpose of this experimental study was to evaluate the range of particulate mass (PM) and particulate number (PN) results from gasoline direct injection (GDI) vehicles by using four test fuels with a range of particulate matter index (PMI) from 1.38 to 2.39 and particulate evaluation index (PEI) from 0.89 to 1.92. The properties of four test fuels were analyzed with detailed hydrocarbon analysis (DHA). Two passenger cars with a GDI engine were tested with four test fuels by conducting the China 6 test procedure, which is equivalent to the worldwide harmonized light-duty vehicle test procedure (WLTP). When the fuels could meet the China 6 primary reference fuel standard with PMI from 1.38 to 2.04 and PEI from 0.89 to 1.59, the PM variation of Vehicle B was from 1.94 mg/km to 3.32 mg/km and of Vehicle A was from 2.55 mg/km to 4.15 mg/km, respectively. In addition, the PN variation of Vehicle B was from 1.57 × 1012 #/km to 3.38 × 1012 #/km and of Vehicle A was from 3.02 × 1012 #/km to 4.80 × 1012 #/km. It was noted that the two different cars had a unique response and sensitivity by using the different fuels, but PMI and PEI did trend with both the PM and the PN response. All PM and PN results from the two cars had an excellent correlation R2 > 0.94 with PMI and R2 > 0.90 with PEI. Therefore, PMI/PEI would be the appropriate specification for sooting tendency in reference fuel standards of emission regulations.

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A Computer Tool for Modelling CO2 Emissions in Driving Cycles for Spark Ignition Engines Powered by Biofuels

Energies ◽

10.3390/en14051400 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1400

Author(s):

Karol Tucki

Keyword(s):

Co2 Emissions ◽

Environmental Protection Agency ◽

Test Procedure ◽

Driving Cycle ◽

Pollutant Emissions ◽

Spark Ignition Engines ◽

Computer Tool ◽

Driving Cycles ◽

Light Duty Vehicle ◽

Vehicle Test

A driving cycle is a record intended to reflect the regular use of a given type of vehicle, presented as a speed profile recorded over a certain period of time. It is used for the assessment of engine pollutant emissions, fuel consumption analysis and environmental certification procedures. Different driving cycles are used, depending on the region of the world. In addition, drive cycles are used by car manufacturers to optimize vehicle drivelines. The basis of the work presented in the manuscript was a developed computer tool using tests on the Toyota Camry LE 2018 chassis dynamometer, the results of the optimization process of neural network structures and the properties of fuels and biofuels. As a result of the work of the computer tool, the consumption of petrol 95, ethanol, methanol, DME, CNG, LPG and CO2 emissions for the vehicle in question were analyzed in the following driving tests: Environmental Protection Agency (EPA US06 and EPA USSC03); Supplemental Federal Test Procedure (SFTP); Highway Fuel Economy Driving Schedule (HWFET); Federal Test Procedure (FTP-75–EPA); New European Driving Cycle (NEDC); Random Cycle Low (×05); Random Cycle High (×95); Mobile Air Conditioning Test Procedure (MAC TP); Common Artemis Driving Cycles (CADC–Artemis); Worldwide Harmonized Light-Duty Vehicle Test Procedure (WLTP).

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Evaluation of a Scale-Resolving Methodology for the Multidimensional Simulation of GDI Sprays

Energies ◽

10.3390/en12142699 ◽

2019 ◽

Vol 12 (14) ◽

pp. 2699 ◽

Cited By ~ 5

Author(s):

Giovanni Di Ilio ◽

Vesselin K. Krastev ◽

Giacomo Falcucci

Keyword(s):

Turbulence Modeling ◽

Direct Injection ◽

Test Procedure ◽

Hybrid Approach ◽

Development Trend ◽

Standard Test ◽

Gasoline Direct Injection ◽

Model Parameters ◽

Test Case ◽

Passenger Cars

The introduction of new emissions tests in real driving conditions (Real Driving Emissions—RDE) as well as of improved harmonized laboratory tests (World Harmonised Light Vehicle Test Procedure—WLTP) is going to dramatically cut down NOx and particulate matter emissions for new car models that are intended to be fully Euro 6d compliant from 2020 onwards. Due to the technical challenges related to exhaust gases’ aftertreatment in small-size diesel engines, the current powertrain development trend for light passenger cars is shifted towards the application of different degrees of electrification to highly optimized gasoline direct injection (GDI) engines. As such, the importance of reliable multidimensional computational tools for GDI engine optimization is rapidly increasing. In the present paper, we assess a hybrid scale-resolving turbulence modeling technique for GDI fuel spray simulation, based on the Engine Combustion Network “Spray G” standard test case. Aspects such as the comparison with Reynolds-averaged methods and the sensitivity to the spray model parameters are discussed, and strengths and uncertainties of the analyzed hybrid approach are pointed out. The outcomes of this study serve as a basis for the evaluation of scale-resolving turbulence modeling options for the development of next-generation directly injected thermal engines.

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Effect of Fuel Economy on Automobile Safety

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198105194100101 ◽

2005 ◽

Vol 1941 (1) ◽

pp. 1-7 ◽

Cited By ~ 6

Author(s):

Sanjana Ahmad ◽

David L. Greene

Keyword(s):

Fuel Economy ◽

Negative Relationship ◽

Cointegration Analysis ◽

Corporate Average Fuel Economy ◽

Traffic Fatalities ◽

Passenger Cars ◽

Light Duty ◽

Light Trucks ◽

Short Period ◽

Light Duty Vehicle

Since 1975, the fuel economy of passenger cars and light trucks has been regulated by the corporate average fuel economy (CAFE) standards, established during the energy crises of the 1970s. Calls to increase fuel economy are usually met by a fierce debate on the effectiveness of the CAFE standards and their impact on highway safety. A seminal study of the link between CAFE and traffic fatalities was published by R. W. Crandall and J. D. Graham in 1989. They linked higher fuel economy levels to decreases in vehicle weight and correlated the decline in new car weight with about a 20% increase in occupant fatalities. The time series available to them, 1947–1981, includes only the first 4 years of fuel economy regulation, but any statistical relationship estimated over such a short period is questionable. This paper reexamines the relationship between U.S. light-duty vehicle fuel economy and highway fatalities from 1966 to 2002. Cointegration analysis reveals that the stationary linear relationships between the average fuel economy of passenger cars and light trucks and highway fatalities are negative: higher miles per gallon is significantly correlated with fewer fatalities. Log–log models are not stable and tend to produce statistically insignificant (negative) relationships between fuel economy and traffic fatalities. These results do not definitively establish a negative relationship between light-duty vehicle fuel economy and highway fatalities; instead they demonstrate that national aggregate statistics cannot support the assertion that increased fuel economy has led to increased traffic fatalities.

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Exhaust Emissions and Energy Consumption Analysis of Conventional, Hybrid, and Electric Vehicles in Real Driving Cycles

Energies ◽

10.3390/en13236423 ◽

2020 ◽

Vol 13 (23) ◽

pp. 6423

Author(s):

Jacek Pielecha ◽

Kinga Skobiej ◽

Karolina Kurtyka

Keyword(s):

Energy Consumption ◽

Electric Vehicle ◽

Electric Vehicles ◽

Carbon Dioxide Emissions ◽

Gasoline Engine ◽

Exhaust Emissions ◽

Hybrid Vehicles ◽

The European Union ◽

Passenger Cars ◽

Traffic Conditions

One of the environmental aims of the European Union is to achieve climate neutrality by 2050. According to European Parliament data, transport emissions accounted for about 25% of global carbon dioxide emissions in 2016, in which road transport had the largest share (approximately 72%). This phenomenon is particularly visible in urban agglomerations. The solution examples are the popularization of hybrid vehicles and the development of electromobility. The aim of this paper is an assessment of the energy consumption and exhaust emissions from passenger cars fitted with different powertrains in actual operation. For the tests, passenger cars with conventional engines of various emission classes were used as well as the latest hybrid vehicles and an electric car. It enabled a comparative assessment of the energy consumption under different traffic conditions, with particular emphasis on the urban phase and the entire RDE (Real Driving Emissions) test. The results were analyzed to identify changes in these environmental factors that have occurred with the technical advancement of vehicles. The lowest total energy consumption in real traffic conditions is characteristic of an electric vehicle; the plug-in hybrid vehicle with a gasoline engine is about 10% bigger, and the largest one is a combustion vehicle (30% bigger than an electric vehicle). These data may contribute to the classification of vehicles and identification of advantages of the latest developments in conventional, hybrid, and electric vehicles.

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Measurement and Evaluation of Real-World Speed and Acceleration Activity Envelopes for Light-Duty Vehicles

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/2503-14 ◽

2015 ◽

Vol 2503 (1) ◽

pp. 128-136 ◽

Cited By ~ 8

Author(s):

Bin Liu ◽

H. Christopher Frey

Keyword(s):

Real World ◽

Test Procedure ◽

Accurate Estimation ◽

Vehicle Type ◽

Light Duty ◽

Road Grade ◽

Light Duty Vehicle ◽

Curb Weight ◽

Vehicle Activity ◽

Light Duty Vehicles

Accurate estimation of vehicle activity is critically important for the accurate estimation of emissions. To provide a benchmark for estimation of vehicle speed trajectories such as those from traffic simulation models, this paper demonstrates a method for quantifying light-duty vehicle activity envelopes based on real-world activity data for 100 light-duty vehicles, including conventional passenger cars, passenger trucks, and hybrid electric vehicles. The vehicle activity envelope was quanti-fied in the 95% frequency range of acceleration for each of 15 speed bins with intervals of 5 mph and a speed bin for greater than 75 mph. Potential factors affecting the activity envelope were evaluated; these factors included vehicle type, transmission type, road grade, engine displacement, engine horsepower, curb weight, and ratio of horsepower to curb weight. The activity envelope was wider for speeds ranging from 5 to 20 mph and narrowed as speed increased. The latter was consistent with a constraint on maximum achievable engine power demand. The envelope was weakly sensitive to factors such as type of vehicle, type of transmission, road grade, and engine horsepower. The effect of road grade on cycle average emissions rates was evaluated for selected real-word cycles. The measured activity envelope was compared with those of dynamometer driving cycles, such as the federal test procedure, highway fuel economy test, SC03, and US06 cycles. The effect of intervehicle variability on the activity envelope was minor; this factor implied that the envelope could be quantified based on a smaller vehicle sample than used for this study.

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Meeting the Challenge: A Stochastic Assessment of the U.S. Light-Duty Vehicle Fuel Economy Standards

ASME 2012 6th International Conference on Energy Sustainability, Parts A and B ◽

10.1115/es2012-91172 ◽

2012 ◽

Cited By ~ 1

Author(s):

Parisa Bastani ◽

John B. Heywood ◽

Chris Hope

Keyword(s):

Fuel Economy ◽

Ghg Emissions ◽

Corporate Average Fuel Economy ◽

Passenger Cars ◽

Policy Model ◽

Light Duty ◽

Stochastic Transport ◽

Light Trucks ◽

Light Duty Vehicle ◽

The U.S

The U.S. Department of Transport and EPA have recently proposed further regulation of the light-duty vehicle corporate average fuel economy and GHG emissions for model years 2017 to 2025. Policy makers are setting more stringent targets out to 2025 in a context of significant uncertainty. These uncertainties need to be quantified and taken into account systematically when evaluating policies. In this paper, a stochastic technology and market vehicle fleet analysis is carried out, using the STEP (Stochastic Transport Emissions Policy model), to assess the probability of meeting the proposed CAFE targets in 2016 and 2025, and identify factors that play key roles in the near and midterm. Our results indicate that meeting the proposed targets requires (a) aggressive technological progress rate and deployment, (b)aggressive market penetration of advanced engines and powertrains, (c) aggressive vehicle downsizing and weight reduction, and (d) a high emphasis on reducing fuel consumption. Three scenarios are examined to assess the likelihood of meeting the proposed targets. The targets examined here, 32.5 and 34.1 mpg in 2016 and 44 and 54.5 mpg in 2025, are reduced from the nominal CAFE values after allowing for the various credits in the proposed rulemaking. The results show that there is about a 42.5% likelihood of the passenger cars average fuel economy falling below 32.5 mpg and a 5.3% likelihood of it exceeding 34.1 mpg in 2016, and about a 4% chance of it exceeding 44 mpg in 2025, under the plausible-ambitious scenario. Under the EPA/DOT preferred alternative scenario, the likelihood of passenger cars average fuel economy meeting or exceeding 34.1 mpg in 2016 and 44 mpg in 2025 increases to about 74% and 34.5% respectively. The probability of meeting these combined CAFE targets drops to less than 1% in both near and mid terms, once light trucks are included in the mix. This analysis quantifies the probability of meeting the targets therefore to enable risk-based contingency planning, and identifies key drivers of uncertainty where further strategic research is needed.

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