Driving and Engine Cycles Evangelos G

Driving and Engine Cycles Evangelos G. Giakoumis

Driving and Engine Cycles

123 Evangelos G. Giakoumis Department of Thermal Engineering, School of Mechanical Engineering National Technical University of Athens Athens Greece

ISBN 978-3-319-49033-5 ISBN 978-3-319-49034-2 (eBook) DOI 10.1007/978-3-319-49034-2

Library of Congress Control Number: 2016956823

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This Springer imprint is published by Springer Nature The registered company is Springer International Publishing AG The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland Preface

Environmental pollution has been one of the most significant threats faced by mankind in the last decades. It affects severely the whole planet, resulting in mil- lions of premature deaths every year, degradation of the human life level, and considerable financial burden on individuals and the whole society. Passenger cars, light- and heavy-duty trucks and buses, and non-road equipment, i.e., vehicles powered by fossil-fueled internal combustion engines, are among the major con- tributors to the anthropogenic-related environmental issues, particularly in large cities. The authorities, having acknowledged this fact from the early 50s, proceeded to various measures, such as legislation of gradually stricter emission limits, cleaner fuels, inspection and maintenance tests. Many books have been published in the last decades dealing with vehicular-related environmental issues. A lot of these books have focused on emission limits and emission legislation in general. Others deal with pollutant emissions analyzing their production mechanisms; additionally, a significant por- tion has been concerned with after-treatment control. None of these subjects are dealt with in this book. In contrast, it seems that there has been no book dealing exclusively with certification cycles, i.e., the test schedules employed at type approval level to test the vehicle, being representative of the concerned vehicle’sor engine’s duty cycle. Instead, with few exceptions, driving cycles have been presented in the past mainly as ‘accompanying text’ to manuscripts dealing with pollutant regulations and emission limits. Since, to the best of the author’s knowledge, no comprehensive analysis of drive cycles has ever been attempted, this is the gap in the open literature that the present book aims to fill. In the following chapters, an effort has been made to cover all possible subjects related to drive cycles, namely describe what a test cycle is, how it is constructed, and provide detailed historical information on the development of the most influential certification test schedules employed in the past. Moreover, the short- comings of the various cycles with respect to their representativeness (in terms of driving activity and emission results) will be highlighted, as well as their most important technical specifications. The book also aims to combine this information with typical performance and emission results from real vehicles operation, in order

v vi Preface for the reader to draw a more complete picture on how the vehicle/engine behaves during a test cycle regarding development of engine speed, torque, power, as well as pollutant emissions. The results that will be presented stem from both (experi- mentally validated) simulations and experiments. Moreover, an extensive part of the book is dedicated to engine-dynamometer cycles, for heavy-duty and non-road engines/vehicles, which have been dealt with in the past even more scarcely. It should be pointed out that it has never been the intention to provide an exhaustive list of all test cycles or their technical specifications. This holds true as regards the numerous non-legislated test schedules. For legislated cycles, on the other hand, a detailed presentation of all of them will be provided. Owing to the availability of large amount of data regarding U.S., European, and (recently developed) worldwide regulations, these cycles will be presented in more detail, particularly vis-à-vis their historical background. On the other hand, owing to language limitations and reluctance of the relevant authorities in Japan to provide background information, the analysis of Japanese test cycles will be considerably shorter. The discussion of drive cycles will be primarily from a mechanical engi- neer’s point of view and only secondarily from a traffic engineering perspective. The book is organized as follows: Chap. 1 serves as an introduction to driving cycles and test procedures in general. Test cycles are defined and classified with the focus on why certification cycles for all kinds of vehicles should be transient. A description of the main attributes follows for all cycle types (chassis and engine, modal and transient). Emphasis is given here on representativeness issues, also providing and analyzing various cycle metrics. The procedure followed when constructing a driving cycle is also discussed at the end of the chapter. Chapters 2 and 3 provide details on driving cycles for passenger cars and light-duty trucks, which form the biggest and oldest category (Chap. 2), and motorcycles (Chap. 3). These have been exclusively of the chassis-dynamometer type. Test cycles for heavy-duty engines/vehicles are discussed in Chap. 4. An interesting characteristic for these test schedules is that both chassis and engine-dynamometer cycles have been employed in the past, the latter on a stationary or transient form. All of them are discussed in detail. Chapter 5 deals with non-road engines/vehicles, such as those utilized in agricultural and construction equipment, marine and locomotive applications. The relevant cycles here are exclusively of the engine-dynamometer type. Lastly, Chap. 6 serves as an introduction to the experimental procedure during vehicle or engine certification in the laboratory, discussing the driving cycle test. Various topics are dealt with such as type approval issues, dynamometers, the coast-down test, and, primarily, the experimental setup and the equations used to calculate emissions and fuel consumption during the cycle execution in the laboratory. One inherent feature of test cycles is their numerous technical specifications. These are provided collectively in the Appendix, for the most important schedules, and on a relatively detailed basis. It was intentional to not incorporate many ‘numbers’ inside the text. In any case, some technical specifications are important to supply context, particularly when comparing cycles; such comparisons form an Preface vii important component of the book. In order to understand the basis under which these technical characteristics have been derived, the interested reader is advised to check initially the introductory text in the Appendix, where the exact equations/logic is provided. Although the biggest part of the book deals with driving cycles, i.e., those executed on a chassis-dynamometer where the whole vehicle is under test, it was decided to title the book ‘Driving and Engine Cycles’ so as to cover the second important category as well, namely engine-dynamometer cycles, which are also discussed in detail. The present book is intended to serve as a reference for engineers and researchers, but it should also be useful to students as a supplementary text on exhaust pollution courses. Although for much of its length, it does not require specific technical knowledge and can be rather easily conceived by most people involved in the research and study of engine emissions and fuel economy, it is expected that the reader is already familiar with emission regulation matters and with some basic aspects of internal combustion engines operation. Lastly, and bearing in mind that the broad subject of emission legislation is constantly evolving, the reader should always have in mind that a regulation valid when preparing this book (2016) might have been superseded at the time of reading it.

Athens, Greece November 2016 Evangelos G. Giakoumis Acknowledgments

The author wishes to acknowledge several individuals who helped in various ways the writing of this book, namely Prof. Emeritus C.D. Rakopoulos, Prof. D.T. Hountalas, Dr. A. Dimaratos, Prof. D.C. Kyritsis, Ms. S. Schmidt, Ms. Anna Eleni Giakoumi, Messrs R. Brezny, Z. Chen, K. Chun, M. Cox, T. Drongitis, K. Engeljehringer, A. Kerkhof, C. Mi, N.-O. Nylund, S. Park, S. Zhang, T. Zheng, as well as various current and former employees of the U.S. Environmental Protection Agency (C. Courtois, C. France, J. France, J. Spieth, and T. Wysor). Work conducted over the past few years by some of my students, under my supervision, is also presented in the next chapters. The contribution of A. Alafouzos, A. Alysandratou, S. Lioutas, N. Kakouras, G. Triantafyllou, E. Velidakis, C. Vitsas, and A. Zahiotis is greatly acknowledged. I would also like to express my gratitude to the supporting staff at Springer for their continuous help. Lastly, the various publishers and companies that have granted permission to reproduce ﬁgures and photographs from their publications are gratefully acknowledged; they are also credited in the text.

ix Contents

1 Introduction...... 1 1.1 Motor Vehicles: Environmental Pollution, Emission Legislation and Recent Trends ...... 1 1.2 The Importance of Transient Operation ...... 10 1.3 Fundamentals of Test Cycles ...... 16 1.3.1 Chassis-Dynamometer Cycles ...... 23 1.3.2 Engine-Dynamometer Cycles ...... 38 1.4 Drive Cycle Development Process ...... 46 1.4.1 Collection of Driving Data ...... 48 1.4.2 Data Analysis and Cycle Construction ...... 54 References...... 60 2 Light-Duty Vehicles...... 65 2.1 European Union ...... 65 2.1.1 European Driving Cycle ECE+EUDC/NEDC ...... 67 2.1.2 Non-legislated Cycles ...... 81 2.2 United States of America ...... 87 2.2.1 California 7-Mode...... 88 2.2.2 FTP-72 and FTP-75 ...... 90 2.2.3 Highway Fuel Economy Test—HFET...... 95 2.2.4 Supplemental FTP US06 and SC03 ...... 98 2.2.5 New York City Cycle—NYCC...... 109 2.2.6 California LA-92...... 111 2.2.7 Special Purpose Cycles ...... 113 2.3 Japan ...... 126 2.3.1 4-Mode—J4 ...... 127 2.3.2 10-Mode—J10 ...... 128 2.3.3 11-Mode—J11 ...... 128 2.3.4 10-15 Mode—J10-15 ...... 130 2.3.5 JC08 ...... 131

xi xii Contents

2.4 Australia ...... 135 2.5 Worldwide—WLTC ...... 138 2.6 Other Countries ...... 145 2.7 Comparative Data ...... 147 References...... 162 3 Motorcycles ...... 167 3.1 ECE R47 ...... 168 3.2 ECE R40 ...... 171 3.3 U.S. EPA Urban Dynamometer Driving Schedule ...... 174 3.4 Indian Driving Cycle—IDC ...... 177 3.5 Worldwide Motorcycle Test Cycle—WMTC ...... 178 References...... 190 4 Heavy-Duty Vehicles and Engines ...... 193 4.1 Introduction ...... 193 4.2 Europe ...... 197 4.2.1 Free Acceleration Test ...... 198 4.2.2 Steady-State R49...... 199 4.2.3 Chassis-Dynamometer FIGE ...... 200 4.2.4 Steady-State ESC ...... 202 4.2.5 ELR Smoke Test...... 206 4.2.6 Transient ETC...... 207 4.2.7 Other European Non-legislated Chassis-Dynamometer Cycles ...... 211 4.3 United States of America ...... 215 4.3.1 Steady-State Gasoline 9 Mode ...... 216 4.3.2 Steady-State Diesel 13 Mode ...... 218 4.3.3 Federal Smoke Test...... 220 4.3.4 Chassis-Dynamometer Heavy-Duty UDDS ...... 221 4.3.5 Transient FTP ...... 227 4.3.6 Snap Acceleration Test ...... 236 4.3.7 Other U.S. Non-legislated Chassis-Dynamometer Cycles ...... 236 4.4 Japan ...... 246 4.4.1 Steady-State 6 Mode ...... 246 4.4.2 Steady-State 13 Mode ...... 248 4.4.3 Chassis-Dynamometer JE05 ...... 249 4.5 Worldwide ...... 252 4.5.1 Chassis-Dynamometer WTVC...... 252 4.5.2 Transient WHTC...... 256 4.5.3 Steady-State WHSC ...... 261 4.6 Other Countries ...... 265 Contents xiii

4.7 Comparative Results ...... 269 4.7.1 Chassis-Dynamometer Cycles ...... 269 4.7.2 Engine-Dynamometer Cycles ...... 272 References...... 281 5 Non-Road Engines...... 285 5.1 Steady-State Cycles ...... 286 5.2 Transient Cycles ...... 295 References...... 313 6 Driving Cycles Test Procedure ...... 315 6.1 Introduction ...... 315 6.2 Dynamometers ...... 318 6.3 Road-Load Equation...... 320 6.4 Coast-Down Procedure ...... 322 6.5 Emissions Measurement ...... 325 6.5.1 Chassis Testing Employing Constant Volume Sampling...... 326 6.5.2 Engine-Dynamometer Testing ...... 336 References...... 344 Appendix A—Technical Speciﬁcations of Chassis-Dynamometer Cycles ...... 347 Notation

a Acceleration (m/s2) A Area (m2) C Concentration (ppm or %) E Emission (g or g/km or g/kWh) f Sampling frequency (Hz) F Force (N) g Gravitational acceleration (m/s2) H Humidity (g water/kg dry air) Kh NOx humidity correction factor Kr Multiplicative regeneration factor m, M Mass (g or kg) N Rotational speed (rpm) or Number p Pressure (Pa or bar) P Power (kW) S Distance (m or km) t Time (s) T Absolute temperature (K) or Torque (Nm) V Volume (m3) or vehicle speed (km/h or mph) W Work (J) or weight (kg)

Greek symbols h Road grade (%) H Moment of inertia (kgm2) q Density (kg/m3) r Standard deviation

xv xvi Notation

Subscripts a Aerodynamic act Actual d Dry or drag da Dilution air deg Diluted exhaust gas eg Exhaust gas f Frontal or fuel fr Friction g Gas gr Gravitational or grade i Each pollutant in Inertia j Each mode norm Normalized PM Particulate matter r Rolling or regeneration ref Reference tr Traction V Vehicle w Wet or weighted

Abbreviations ACEA Association des Constructeurs Européens d’ Automobiles (European Automobile Manufacturers Association), www.acea.be AMA Approved mileage accumulation (cycle) CAA Clean Air Act CAAA Clean Air Act Amendments CARB California Air Resources Board, http://www.arb.ca.gov CBD Central business district CFR Code of federal regulations (USA), www.ecfr.gov CFV Constant ﬂow venturi CH4 Methane CI Compression ignition CNG Compressed natural gas CO Carbon monoxide CO2 Carbon dioxide CUEDC Composite urban emissions drive cycle CVS Constant volume sampling (a universally applied technique for measuring pollutants mass emissions during driving cycles—Chap. 6) CWF Carbon weight fraction DF Dilution factor Notation xvii

DI Direct injection (fuel injection takes place inside the cylinder after the intake valves have closed) DOC Diesel oxidation catalyst (a catalytic converter employed in diesel engines for oxidation of CO and HC to CO2 and H2O) DPF Diesel particulate filter (the DPF traps particulates; these are periodically burned through an ECU-initiated brief regeneration event involving high-load operation that generates exhaust gas temperatures in the range of 500–550 °C capable of burning the particulates and restoring the trap) EC European Commission, http://ec.europa.eu ECU Engine control unit (an electronic unit that gathers engine and vehicle data from various sensors, processes them based on stored maps, and determines, through various actuators, the exact timing of fuel injection, spark plug ignition, etc.) EEA European Environment Agency, http://www.eea.europa.eu EEC European Economic Community (the predecessor of European Union, 1958–1993) EEV Enhanced environment-friendly vehicle EGR Exhaust gas recirculation (part of the exhaust gas leaving the cylinder, after being cooled, is inducted into the engine in order to limit in-cylinder combustion temperatures and reduce the production of NOx) ELR European Load Response EPA Environmental Protection Agency (USA), https://www3.epa.gov ESC European steady-state cycle ETC European transient cycle EU European Union, http://europa.eu EUDC Extra urban driving cycle EV Electric vehicle FC Fuel consumption FIGE Forschungsinstitut für Geräusche und Erschütterungen FR Federal register FTP Federal test procedure GDI Gasoline direct injection (type of spark ignition engine that applies a stratified charge (rich in the vicinity of the spark plug and leaner toward the cylinder walls), primarily aiming to reduce fuel consumption) GDP Gross domestic product GHG Greenhouse gas GPF Gasoline particulate filter GRPA Group de Rapporteurs sur la Pollution de l’Air GRPE Group de Rapporteurs sur la Pollution et l’ Énergie GTR Global technical regulation GVW Gross vehicle weight (maximum operating weight of a vehicle including the vehicle’s chassis, body, engine, engine fluids, fuel, accessories, driver, passengers, and cargo, according to the legislation) xviii Notation

HC Hydrocarbons HD Heavy duty HDE Heavy-duty engine HDV Heavy-duty vehicle HEV Hybrid-electric vehicle HFET Highway fuel economy test HHDDT Heavy heavy-duty diesel truck (cycle) I.C. Internal combustion I/M, IM Inspection and maintenance ICCT International Council on Clean Transportation IDC Indian driving cycle ISO International Organization for Standardization, http://www.iso.org LD Light duty LDT Light-duty truck LDV Light-duty vehicle LEV Low-emission vehicle LNT Lean NOx trap, also known as NOx adsorber (deNOx after-treatment system employing zeolite as adsorbent, where NOx is trapped; the filter requires some kind of periodic regeneration to be restored/emptied) LoS Level of service (measure used to describe the quality of traffic conditions) LPG Liquefied petroleum gas MDPV Medium-duty passenger vehicle MOVES Motor vehicle emission simulator mph Miles per hour MVEG Motor vehicle emissions group MY Model year NEDC New European driving cycle NG Natural gas NHTSA National Highway Traffic Safety Administration (USA), http://www.nhtsa.gov NMHC Non-methane hydrocarbons NMOG Non-methane organic gases (the sum of non-oxygenated and oxygenated hydrocarbons contained in a gas sample, including, at a minimum, all oxygenated organic gases containing 5 or fewer carbon atoms (i.e., aldehydes, ketones, alcohols, and ethers), and all known alkanes, alkenes, alkynes, and aromatics containing 12 or fewer carbon atoms, excluding methane) NOx Nitrogen oxides NRSC Non-road steady-state cycle NRTC Non-road transient (composite) cycle NTE Not to exceed NYCC New York city cycle OBD On-board diagnostics Notation xix

OCE Off-cycle emissions OCTA Orange County Transportation Authority OICA Organisation Internationale des Constructeurs d’Automobiles (International Organization of Motor Vehicle Manufacturers), www.oica.net OPEC Organization of the Petroleum Exporting Countries PDP Positive displacement pump PEMS Portable emissions measurement system PFI Port fuel injection (conventional spark ignition engine, where the fuel is injected onto the inlet valve and is mixed with the incoming air) PFSS Partial flow sampling system PI Positive ignition PKE Positive kinetic energy (m/s2)—Eq. (1.3) PM Particulate matter PMR Power-to-mass ratio (kW/t) PN Particle number RDE Real driving emissions RMC Ramped modal cycle RPA Relative positive acceleration (m/s2)—Eq. (1.2) SAE Society of automotive engineers SAFD Speed/acceleration frequency distribution SBC Standard bench cycle SCR Selective catalytic reduction (a, usually, vanadium-based catalyst, where NOx is reduced to N2 employing ammonia NH3; in most cases, a liquid urea solution is injected in the exhaust gas stream prior to the SCR that is then converted to ammonia) SET Supplemental emission test, or sulfate emission test SFTP Supplemental federal test procedure SI Spark ignition SRC Standard road cycle THC Total hydrocarbons TRIAS Test Requirements and Instructions for Automobile Standards (Japan) UDC Urban driving cycle UDDS Urban dynamometer driving schedule UN United Nations, http://www.un.org UNECE United Nations Economic Commission for Europe, http://www.unece.org VPR Volatile particle remover VSP Vehicle specific power (kW/t)—Eq. (1.4) wf Weighting factor (%) WHDC Worldwide harmonized Heavy-Duty Certification Procedure WHSC Worldwide harmonized Steady-State Cycle WHTC Worldwide harmonized Transient Cycle xx Notation

WLTC Worldwide harmonized Light-Duty Driving Test Cycle WLTP Worldwide harmonized Light-Duty Vehicles Test Procedure WMTC Worldwide harmonized Motorcycle Emissions Certiﬁcation/Test Procedure WOT Wide open throttle WTVC Worldwide Transient Vehicle Cycle