Modeling Tools for Predicting the Impact of Modeling Tools for Predicting the Impact of Rolling Resistance on Energy Usage and Fuel Rolling Resistance on Energy Usage and Fuel

Efficiency for Realistic Driving CyclesEfficiency for Realistic Driving Cycles

CEC Workshop on Fuel Efficient Tires - 2002

Sacramento, CA

September 19, 2002

Kenneth J. KellySenior Engineer, Vehicle Systems Analysis Team

National Renewable Energy Laboratory

NREL MissionNREL Mission Lead the nation toward a sustainable energy future by Lead the nation toward a sustainable energy future by

developing renewable energy technologies, improving energy developing renewable energy technologies, improving energy efficiency, advancing related science and engineering, and efficiency, advancing related science and engineering, and facilitating commercializationfacilitating commercialization

Established in 1977 as Solar Energy Research Institute Established in 1977 as Solar Energy Research Institute (Achieved National Laboratory status in 1992)(Achieved National Laboratory status in 1992)

One of eleven DOE National LaboratoriesOne of eleven DOE National Laboratories

Current staff of approximately 1,000Current staff of approximately 1,000

Estimated operating budget of $200MEstimated operating budget of $200M

NREL BackgroundNREL Background

US Big 3 PartnershipUS Big 3 PartnershipHV program: 55 mpgHV program: 55 mpgPNGV: 80 mpg goal PNGV: 80 mpg goal

FreedomCARFreedomCAR

Vehicle Climate Control

Battery Thermal Management

Vehicle SystemsVehicle SystemsAnalysisAnalysis

Digital FunctionalDigital FunctionalVehicleVehicle

Advanced Vehicle Technologies Program

GMGMFordFordDaimlerChryslerDaimlerChrysler

Potential for Large Energy SavingsPotential for Large Energy Savings

Potential to Reduce Environmental ImpactsPotential to Reduce Environmental Impacts

Impact on the Existing Fleet of VehiclesImpact on the Existing Fleet of Vehicles

Cross-Platform ApplicationCross-Platform Application

Large and Important U.S. IndustryLarge and Important U.S. Industry

No Massive Infrastructure Changes RequiredNo Massive Infrastructure Changes Required

Potentially Low Incremental CostPotentially Low Incremental Cost

No Drastic Change in Consumer Behavior RequiredNo Drastic Change in Consumer Behavior Required

NREL’s Interest in Tires

Highway Energy Consumption GAP

2.7 mbpd2.7 mbpd

6.7 mbpd6.7 mbpd

Potential Energy Savings in the Transportation Sector

Total year 2005 savingsTotal year 2005 savings3.8 billion gal /year3.8 billion gal /year

Equivalent to replacing average car with: 15.7 MILLION Toyota Priuses

Introducing: NREL’s Advanced Vehicle Simulator

Introducing: NREL’s Advanced Vehicle Simulator

Available on the world wide web at:Available on the world wide web at:

(http://www.ctts.nrel.gov/analysis)

Three Main ADVISOR GUI Screens Vehicle InputVehicle Input

Simulation SetupSimulation Setup

ResultsResults

Basic Structure (database) How the Data/Models are Pulled into the GUI

BlockBlockDiagramDiagram

GUIGUI

Data FilesData Files

Basic Structure (models) In the Matlab/Simulink Environment

BlockBlockDiagramDiagram

LibrariesLibraries

BatteryBattery

EngineEngineControlControl

ADVISOR Setup Screen with Tire Menu

2cVbVaLPFR

New rolling resistance model in ADVISOR 2002 with J2452 test data supplied by Michelin

ADVISOR Rolling Resistance Block Diagram

2001 OE Fitments Size alpha beta a b c mass [kg] SMERF [N] SMERF P SMERF ZMercury Cougar P205/60R15 -0.4815 1.0051 6.82E-02 2.32E-04 1.20E-06 8.23 24.75 260 4051.5Kia Optima P205/60R15 -0.4745 0.9552 1.50E-01 4.87E-04 1.18E-06 9.51 35.98 260 4051.5Mazda 626 P205/60R15 -0.4243 0.9568 1.59E-01 3.44E-04 1.25E-06 10.55 48.63 260 4051.5

Volkswagen Eurovan P205/60R16 -0.4428 0.9036 2.11E-01 6.00E-04 2.17E-06 10.42 40.53 260 4223.1Honda Accord EX Coupe V6 P205/60R16 -0.3388 0.9375 1.01E-01 1.59E-04 9.93E-07 9.71 43.32 260 4223.1Dodge Stratus ES

Toyota Camry P205/65R15 -0.3937 0.8901 1.66E-01 3.50E-04 2.09E-06 9.71 37.41 260 4360.3Honda Accord LX & EX Sedan V6 P205/65R15 -0.3947 0.9468 1.13E-01 1.89E-04 2.24E-06 10.35 40.78 260 4360.3Hynudai XG300 P205/65R15 -0.3191 0.9076 1.23E-01 1.96E-04 1.52E-06 10.52 47.35 260 4360.3Lexus ES 300Nissan MaximaSaturn L Series

Subaru Outback P225/60R16 -0.4814 0.9463 1.47E-01 3.69E-04 2.38E-06 12.95 38.33 260 5012.7Ford Crown Victoria P225/60R16 -0.3881 0.9550 1.03E-01 1.46E-04 2.19E-06 11.08 47.21 260 5012.7Dodge Intrepid P225/60R16 -0.5888 1.0921 7.93E-02 1.18E-04 3.52E-07 15.29 55.69 260 5012.7Lincoln Town Car

Ford F150 P235/70R16 -0.4704 1.0129 8.49E-02 1.16E-04 2.64E-06 12.86 51.14 260 6180.3Mazda Tribute LX & ES P235/70R16 -0.4003 0.9315 1.39E-01 2.20E-04 1.90E-06 14.26 57.88 260 6180.3

P235/70R16 -0.4090 0.9765 1.06E-01 1.11E-04 1.52E-06 14.26 61.20 260 6180.3

Ford Explorer P235/75R15 -0.5007 0.9141 2.55E-01 4.69E-04 3.49E-06 13.30 54.08 260 6317.5Dodge Dakota P235/75R15 -0.4797 0.9464 2.08E-01 2.56E-04 3.94E-06 13.31 65.11 260 6317.5Chevy Trailblazer P235/75R15 -0.2601 0.8275 2.00E-01 2.50E-05 4.18E-06 13.80 71.30 260 6317.5Mercury MountaineerMitsubishi Montero Sport ES

Tire Sizes Currently in ADVISOR Database

ADVISOR Simulation Setup Screen with Drive Cycles

ADVISOR Results Screen

ADVISOR Results : Energy Use Figure

ADVISOR Simulation Results : Fr on the EPA’s Highway (HWFET) Cycle

ADVISOR Simulation Results : Fr on the EPA’s Urban (UDDS) Cycle

ADVISOR Simulation Results : Fr on the EPA’s Aggressive Driving (US06)Cycle

ADVISOR Simulation Results : Road-Load Energy and Fuel Economy

3.3%3.3%US06

5.9%5.9%HWFET

2.1%2.1%FTP

% change in FE% change in FE

Low RR vs med RR (30% lower Fr)Low RR vs med RR (30% lower Fr)

ADVISOR Simulation Results : Road-Load Energy and Fuel Economy

1.9%1.9%US06

3.4%3.4%HWFET

1.5%1.5%FTP

% change in FE% change in FE

Low RR vs med RR (19% lower Fr)Low RR vs med RR (19% lower Fr)

0

5

10

15

20

25

30

35

40

0 0.005 0.01 0.015 0.02 0.025

rolling resistance

Fue

l Eco

no

my (

mpg)

Car HWFET

Car City

SUV HWFET

SUV City

Parametric Sweep on rolling resistance showing the effect on fuel economy

ADVISOR is linked to optimization techniques and other tools in our Digital Functional Vehicle toolkit

OptimizationOptimizationToolsTools

ADVISOR

g(x)g(x)

ConstraintFunction

f(x)f(x)

ObjectiveFunction

Bringing it all together with Digital Functional Vehiclean integrated systems approach

NREL’s Energy-Smart Tire Vision

Adaptive Properties and Self

Regulating

• Energy Savings• Improved Performance• Improved Safety

Low Rolling Resistance

• Large Energy Savings

Long Life

• Reduced Solid Waste

• Reduced Particulate Pollution

• Energy Savings from Manufacturing and Materials

Conclusions and Additional Information

Potentially, Large Energy Savings Available from Energy Potentially, Large Energy Savings Available from Energy

Efficient TiresEfficient Tires

Government/Industry Partnership for More Detailed Analysis, Testing Government/Industry Partnership for More Detailed Analysis, Testing

and Directionand Direction

Tires Represent One of Only a Few Opportunities for Energy Savings Tires Represent One of Only a Few Opportunities for Energy Savings

in the Existing Fleet in the Existing Fleet

ADVISOR ModelADVISOR Model- Fast and Accurate Vehicle Systems ModelFast and Accurate Vehicle Systems Model- Free Free (http://www.ctts.nrel.gov/analysis)(http://www.ctts.nrel.gov/analysis)- Open Source CodeOpen Source Code- Vehicle, Component, Drive Cycle Library IncludedVehicle, Component, Drive Cycle Library Included- Conventional and Advanced Vehicle ConfigurationsConventional and Advanced Vehicle Configurations