scholarly journals Analysis of Driving Dynamics Considering Driving Resistances in On-Road Driving

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3408
Author(s):  
Jingeun Song ◽  
Junepyo Cha
Keyword(s):  
Combustion Engine ◽  
Vehicle Speed ◽  
Driving Dynamic ◽  
Engine Emissions ◽  
Engine Load ◽  
Positive Acceleration ◽  
Emission Regulations ◽  
Transportation Emissions ◽  
Light Duty Vehicles ◽  
Dynamic Variables

Internal combustion engine emissions are a serious worldwide problem. To combat this, emission regulations have become stricter with the goal of reducing the proportion of transportation emissions in global air pollution. In addition, the European Commission passed the real driving emissions–light-duty vehicles (RDE-LDV) regulation that evaluates vehicle emissions by driving on real roads. The RDE test is significantly dependent on driving conditions such as traffic or drivers. Thus, the RDE regulation has the means to evaluate driving dynamics such as the vehicle speed per acceleration (v·apos) and the relative positive acceleration (RPA) to determine whether the driving during these tests is normal or abnormal. However, this is not an appropriate way to assess the driving dynamics because the v⋅apos and the RPA do not represent engine load, which is directly related to exhaust emissions. Therefore, in the present study, new driving dynamic variables are proposed. These variables use engine acceleration calculated from wheel force instead of the acceleration calculated from the vehicle speed, so they are proportional to the engine load. In addition, a variable of driving dynamics during braking is calculated using the negative wheel force. This variable can be used to improve the accuracy of the emission assessment by analyzing the braking pattern.

Powertrain Waste Heat Recovery: A Systems Approach to Maximize Drivetrain Efficiency

2012 ◽  
Author(s):  
Kevin Laboe ◽  
Marcello Canova
Keyword(s):  
Fuel Consumption ◽  
Waste Heat Recovery ◽  
Systems Approach ◽  
Waste Heat ◽  
Combustion Engine ◽  
Heat Energy ◽  
Engine Oils ◽  
Engine Cooling ◽  
Light Duty ◽  
Light Duty Vehicles

Up to 65% of the energy produced in an internal combustion engine is dissipated to the engine cooling circuit and exhaust gases [1]. Therefore, recovering a portion of this heat energy is a highly effective solution to improve engine and drivetrain efficiency and to reduce CO2 emissions, with existing vehicle and powertrain technologies [2,3]. This paper details a practical approach to the utilization of powertrain waste heat for light vehicle engines to reduce fuel consumption. The “Systems Approach” as described in this paper recovers useful energy from what would otherwise be heat energy wasted into the environment, and effectively distributes this energy to the transmission and engine oils thus reducing the oil viscosities. The focus is on how to effectively distribute the available powertrain heat energy to optimize drivetrain efficiency for light duty vehicles, minimizing fuel consumption during various drive cycles. To accomplish this, it is necessary to identify the available powertrain heat energy during any drive cycle and cold start conditions, and to distribute this energy in such a way to maximize the overall efficiency of the drivetrain.

The WLTC vs NEDC: A Case Study on the Impacts of Driving Cycle on Engine Performance and Fuel Consumption

2021 ◽  
Vol 18 (3) ◽  
pp. 9071-9081
Author(s):  
Jakub Lasocki
Keyword(s):  
Fuel Consumption ◽  
Combustion Engine ◽  
Engine Performance ◽  
Driving Cycle ◽  
Performance Characteristics ◽  
Pollutant Emission ◽  
Strong Impact ◽  
Light Duty ◽  
Light Duty Vehicles

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.

Effect of Butanol on the Performance of DeNOx Aftertreatment Systems of a Diesel Vehicle Under WLTC Driving Conditions

2021 ◽  
Author(s):  
Alejandro Calle-Asensio ◽  
Juan José Hernández ◽  
José Rodríguez-Fernández ◽  
Víctor Domínguez-Pérez
Keyword(s):  
Catalytic Reduction ◽  
Nox Reduction ◽  
Climatic Conditions ◽  
Transport Sector ◽  
Lean Nox Trap ◽  
Diesel Vehicles ◽  
Medium Speed ◽  
Emission Regulations ◽  
Lean Nox ◽  
Light Duty Vehicles

Abstract Advanced biofuels and electrofuels, among which are medium-long chain alcohols, have gained importance in the transport sector with the enforcement of the EU Renewable Energy Directive (2018/2001). In parallel, last European emission regulations have become much more restrictive regarding NOx, so vehicle manufacturers have been forced to incorporate lean NOx trap (LNT) and/or selective catalytic reduction (SCR). Thus, the combination of modern DeNOx devices and the upcoming higher contribution of sustainable biofuels is a new challenge. In this work, two Euro 6 diesel vehicles, one equipped with LNT and the other with ammonia-SCR, have been tested following the Worldwide harmonized Light-duty vehicles Test Cycle (WLTC) at warm (24°C) and cold (−7°C) conditions using conventional diesel fuel and a diesel-butanol (90/10% vol.) blend. While the effect of butanol on the LNT efficiency was not significant, its influence on the SCR performance was notable during the low and medium-speed phases of the driving cycle, mainly under warm climatic conditions. Despite of the lower NOx concentration at the catalyst inlet, the worst efficiency of the SCR with butanol could be attributed to hydrocarbons deposition on the catalyst surface, which inhibits the NOx reduction reactions with ammonia. Moreover, the LNT was not sensitive to the ambient temperature while the SCR performance greatly depended on this parameter.

scholarly journals Modeling of internal combustion engine emissions by LOLIMOT algorithm

2012 ◽  
Vol 3 ◽  
pp. 251-258 ◽  
Author(s):  
J.D. Martínez-Morales ◽  
Elvia Palacios ◽  
G.A. Veláazquez Carrillo
Keyword(s):  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Engine Emissions

Comparison of Diesel Engine Efficiency and Combustion Characteristics Between Different Bore Engines

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Jue Li ◽  
Timothy J. Jacobs ◽  
Tushar Bera ◽  
Michael A. Parkes
Keyword(s):  
Diesel Engine ◽  
Combustion Engine ◽  
Volume Ratio ◽  
Mechanical Efficiency ◽  
Combustion Characteristics ◽  
Stroke Length ◽  
Engine Load ◽  
Engine Efficiency ◽  
Brake Mean Effective Pressure ◽  
The Difference

This study investigates the effects of engine bore size on diesel engine performance and combustion characteristics, including in-cylinder pressure, ignition delay, burn duration, and fuel conversion efficiency, using experiments between two diesel engines of different bore sizes. This study is part of a larger effort to discover how fuel property effects on combustion, engine efficiency, and emissions may change for differently sized engines. For this specific study, which is centered only on diagnosing the role of engine bore size on engine efficiency for a typical fuel, the engine and combustion characteristics are investigated at various injection timings between two differently sized engines. The two engines are nearly identical, except bore size, stroke length, and consequently displacement. Although most of this diagnosis is done with experimental results, a one-dimensional model is also used to calculate turbulence intensities with respect to geometric factors; these results help to explain observed differences in heat transfer characteristics of the two engines. The results are compared at the same brake mean effective pressure (BMEP) and show that engine bore size has a significant impact on the indicated efficiency. It is found that the larger bore engine has a higher indicated efficiency than the smaller displaced engine. Although the larger engine has higher turbulence intensities, longer burn durations, and higher exhaust temperature, the lower surface area to volume ratio and lower reaction temperature leads to lower heat losses to the cylinder walls. The difference in the heat loss to the cylinder walls between the two engines is found to increase with increasing engine load. In addition, due to the smaller volume-normalized friction loss, the larger sized engine also has higher mechanical efficiency. In the net, since the brake efficiency is a function of indicated efficiency and mechanical efficiency, the larger sized engine has higher brake efficiency with the difference in brake efficiency between the two engines increasing with increasing engine load. In the interest of efficiency, larger bore designs for a given displacement (i.e., shorter strokes or few number of cylinders) could be a means for future efficiency gains.

Influence of Fuel Properties on GDI PM Emissions Over First 200 Seconds of WLTP Using an Engine Dynamometer and Novel “Virtual Drivetrain” Software

2020 ◽  
Author(s):  
Noah R. Bock ◽  
William F. Northrop
Keyword(s):  
Direct Injection ◽  
Regulatory Compliance ◽  
Driving Cycle ◽  
Fuel Properties ◽  
Gasoline Direct Injection ◽  
Particulate Filter ◽  
Vehicle Speed ◽  
Engine Load ◽  
Vehicle Acceleration ◽  
Soot Loading

Abstract The influence of fuel properties on particulate matter (PM) emissions from a catalytic gasoline particulate filter (GPF) equipped gasoline direct injection (GDI) engine were investigated using novel “virtual drivetrain” software and an engine mated to an engine dynamometer. The virtual drivetrain software was developed in LabVIEW to operate the engine on an engine dynamometer as if it were in a vehicle undergoing a driving cycle. The software uses a physics-based approach to determine vehicle acceleration and speed based on engine load and a programed “shift” schedule to control engine speed. The software uses a control algorithm to modulate engine load and braking to match a calculated vehicle speed with the prescribed speed trace of the driving cycle of choice. The first 200 seconds of the WLTP driving cycle was tested using 6 different fuel formulations of varying volatility, aromaticity, and ethanol concentration. The first 200 seconds of the WLTP was chosen as the test condition because it is the most problematic section of the driving cycle for controlling PM emissions due to the cold start and cold drive-off. It was found that there was a strong correlation between aromaticity of the fuel and the engine-out PM emissions, with the highest emitting fuel producing more than double the mass emissions of the low PM production fuel. However, the post-GPF PM emissions depended greatly on the soot loading state of the GPF. The fuel with the highest engine-out PM emissions produced comparable post-GPF emissions to the lowest PM producing fuel over the driving cycle when the GPF was loaded over three cycles with the respective fuels. These results demonstrate the importance of GPF loading state when aftertreatment systems are used for PM reduction. It also shows that GPF control may be more important than fuel properties, and that regulatory compliance for PM can be achieved with proper GPF control calibration irrespective of fuel type.

scholarly journals Optimal and prototype dimensioning of 48V P0+P4 hybrid drivetrains

2020 ◽  
Vol 5 (3-4) ◽  
pp. 173-186
Author(s):  
Matthias Werra ◽  
Axel Sturm ◽  
Ferit Küçükay
Keyword(s):  
Fuel Consumption ◽  
Urban Areas ◽  
Combustion Engine ◽  
Electric Machine ◽  
Prototype Model ◽  
Vehicle Speed ◽  
Conventional Vehicle ◽  
Light Duty ◽  
Consumption Reduction ◽  
And Performance

Abstract This paper presents a virtual toolchain for the optimal concept and prototype dimensioning of 48 V hybrid drivetrains. First, this toolchain is used to dimension the drivetrain components for a 48 V P0+P4 hybrid which combines an electric machine in the belt drive of the internal combustion engine and a second electric machine at the rear axle. On an optimal concept level, the power and gear ratios of the electric components in the 48 V system are defined for the best fuel consumption and performance. In the second step, the optimal P0+P4 drivetrain is simulated with a prototype model using a realistic rule-based operating strategy to determine realistic behavior in legal cycles and customer operation. The optimal variant shows a fuel consumption reduction in the Worldwide harmonized Light Duty Test Cycle of 13.6 % compared to a conventional vehicle whereas the prototype simulation shows a relatively higher savings potential of 14.8 %. In the prototype simulation for customer operation, the 48 V hybrid drivetrain reduces the fuel consumption by up to 24.6 % in urban areas due to a high amount of launching and braking events. Extra-urban and highway areas show fuel reductions up to 11.6 % and 4.2 %, respectively due to higher vehicle speed and power requirements. The presented virtual toolchain can be used to combine optimal concept dimensioning with close to reality behaviour simulations to maximise realistic statements and minimize time effort.

scholarly journals Measuring the Torque of a Combustion Engine.

2018 ◽  
Vol 220 ◽  
pp. 03006 ◽  
Author(s):  
Josef Popelka ◽  
Celestýn Scholz
Keyword(s):  
Combustion Engine ◽  
Torque Sensor ◽  
Engine Load ◽  
The Individual

This paper deals with the measurement of torque using a designed torque sensor. To determine the indicated engine parameters, the torque along with the torque in the combustion space of the individual cylinders are measured. I worked on the measured values to determine the dependence of the torque moments on the engine load. The obtained data was used to assess the possible use for further measurements.

Variation and Control of Small Gasoline Engine Emissions Performance in the Plateau Region

2013 ◽  
Vol 726-731 ◽  
pp. 2022-2025
Author(s):  
Chong Shang Li ◽  
Sheng Ji Liu ◽  
Jian Wang
Keyword(s):  
Gasoline Engine ◽  
Quantitative Relationship ◽  
Mixing Ratio ◽  
Engine Emissions ◽  
Plateau Region ◽  
Gasoline Engines ◽  
Emission Regulations ◽  
Air Intake ◽  
Specific Emissions ◽  
And Control

When small gasoline engines using carburettor are operated in the plateau region, the air intake and fuel supply have different decrease with the altitude increase, and the mixture thicken and the emissions increase. Take outboard marine gasoline engine F15 as an example, the quantitative relationship comparing engines operated on the plateau region to on the plain in same mixing ratio are shown, which includes the power, specific fuel consumption, and CO, HC, NOx specific emissions. And fuel system correction methods are come out to meet EPA emission regulations in different altitudes.

scholarly journals Effects of Vehicle Speed and Engine Load on Motor Vehicle Emissions

2003 ◽  
Vol 37 (17) ◽  
pp. 3739-3746 ◽  
Author(s):  
Andrew J. Kean ◽  
Robert A. Harley ◽  
Gary R. Kendall
Keyword(s):  
Vehicle Emissions ◽  
Motor Vehicle ◽  
Vehicle Speed ◽  
Engine Load ◽  
Motor Vehicle Emissions
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