DISCLAIMER The pinins f the authrs expressed herein d nt necessarily state r reflect thse f the United States Gvernment r the DA, and shall nt be used fr advertising r prduct endrsement purpses. Army Grund Vehicle Prpulsin Pete Schihl TARDEC Grund Vehicle Pwer and Mbility Lab (GVPM) Senir Technical Expert (Prpulsin and Mbility) : Distributin Statement A. Apprved fr public release
Army Grund Vehicle Expectatins Demanding ambient cnditins ranging frm Artic-like t Desert-like dirty envirnment muddy, sandy, and snwy at times Must perate n cmpressin ignitin fuels glbal jet and diesel fuels Must have minimal maintenance schedules Must prtect the ccupants Need t tw ther vehicles, climb steep grades, crner at medium t high speeds, carry arund carg, pull themselves ut f ditch while sitting n ne track, pivt steer, perate in sft sil Increasing need fr mre n-bard electrical pwer 2
Army Grund Vehicle Prpulsin Challenges 1.Cling 2.Cling 3.Fuel Effects 4.Filtratin 5.Emissin standards The Army vehicle cling pint is high tractive effrt t weight under desertlike perating cnditins (ex. 8 tn wheeled vehicle ~0.6 while 30 tn tracked vehicle ~0.7 bth at 120-125 F ambient)
NOx [g/(hp-hr)] U.S. Diesel Emissin Standards 15 Significant Issues fr the Military Grund Vehicles 1974 EPA (HC + NOx) 10 1988 1978 (HC + NOx) 5 Tier IV 1994 1998 2007 1991 2004 (2002) Tier II Tier III 1990 Tier I On-Rad Standards Off-Rad Standards 0 0 0.1 0.25 0.6 1.0 Particulate [g/(hp-hr)]
Engine Emissins Plicy The Army can nt buy 2007 r Tier IV (> 75 bhp) cmpliant COTS engines and directly integrate int current and new heavy-duty vehicles. Cmbat vehicle: permanent armr/attached weapn system Natinal Security Exemptin (NSE) via 40 CFR, 89.908 Tactical Vehicles Withut ARMOR NSE frm 2004 and 2007 standards (i.e. meet 1998) and Tier IV With ARMOR NSE frm ALL standards Declining availability f COTS engines fr Army trucks as suppliers include varius engine emissins technlgies n engines that negatively impact Army vehicle perfrmance/reliability/durability
High Pwer Density Prpulsin Systems Cmbat Vehicles Army definitin f Prpulsin System Pwer Density (PD): PD = sprcket (wheel) pwer / ttal prpulsin system vlume [bhp/ft 3 ] Air filtratin requirements, thermal management system, transmissin, engine, ducting requirements, final drives, fuel tank Bradley FIV r M1: PD = 3 example, M1 gas turbine 291 ft 3 installed vlume: Fuel tank 77 ft 3 ; unused 70 ft 3 ; transmissin 40 ft 3 ; engine 31 ft 3 ; air filtratin 31 ft 3 Bradley FIV: Cummins VTA903 has SHRR f 0.6 BHP/BHP vs. tday s COTS > 0.85 BHP/BHP Future Cmbat System PD target ~ 6 (prjected t be 4.5) Research target: PD > 6-10
JP-8 Prperty Specificatin Challenges Percent f Samples Sulfur cntent: max. 3000 ppm DF-2 : 15 ppm Cetane Index: nne DF-2 : > 40 Density: 0.775 0.84 DF-2 ~ 0.85 Lubricity specif. : nne DF-2 HFRR < 520 45 40 35 30 25 20 15 10 5 0 1.1 1.2 42.1 34.1 32.1 38.9 13.8 12.4 2006 2007 0 500 1000 1500 2000 2500 2850 3000 6.4 7.0 2.9 Sulfur Cncentratin (ppm) Glbal Mean Sulfur Cntent (ppm) 4.2 2006-780 2007-790 2007 High Mean Sulfur Regins Middle East - 930 U.S. East Cast - 2110 1 2.1 0.9
JP-8 Energy Cntent Reductin (MJ/L) 8.0% JP-8 Energy Vlumetric Energy Cntent Relative t DF-2 7.0% 2007 mean 2007 max Wrldwide Mean 3.5% 6.7% 6.7% 6.0% 5.5% 5.6% 5.8% 5.0% 4.7% 4.5% 4.2% 4.4% 4.4% 4.7% 4.2% 4.0% 3.2% 3.3% 3.7% 3.8% 3.5% 3.0% 2.0% 1.0% 0.8% 0.0% east cast east central gulf cast west central west cast middle east eurpe pacific wrldwide KEY POINT: Lwer vlumetric energy density implies less energy in the fuel tank and thus reduced vehicle range
Percent f Samples JP-8 Cetane Index Wrldwide Trend in 2007 40 35 2007 Wrldwide Cetane Index Middle East 37.59 34.99 30 25 20 Mean reginal CI Middle East 46 U.S. Pacific 40.8 18.66 Mean Wrldwide CI Value since 2003 : 43-44 15 10 5 0 Key pint: Tward cmbustin stability issues 0.03 0.33 3.87 U.S. diesel fuel 35.1 36 39 42 45 48 51 54.4 Cetane Index 4.53 0.01
PERFORMANCE CHALLENGES: Fuel Ecnmy/Pwer Density/Electrical Pwer Trade-ffs Vehicle mbility requirements and alltted cling grill surface area drive final pwertrain architecture Cmbat vehicles mre cnstrained n grill size Tend t use specialty engines High tractive effrt t weight requirement (cling issue) Wheeled vehicles may r may nt have ram air Tend t use COTS engines Mre readily lend fr a gd cmbinatin f pwer density and fuel ecnmy due t less restrictive mbility requirements and less restrictive cling air flw (thugh V-hull design is a challenge) COTS vehicles rely n under vehicle airflw fr cling purpses Generatin f electrical pwer (up t 200 kw) Reduced pwer density (additinal prpulsin system vlume) additinal cling system capacity (larger heat exchangers and/r large parasitic fan pwer) May r may nt imprve fuel ecnmy as a strng functin f duty cycle 10
CHALLENGE AREAS fr Army Grund Vehicles Relevant t ARC Hybrid Electric Prpulsin High temperature perating capability w/ the need fr lw temperature air/water cling system Wide range and highly efficient generatrs/mtrs Battery packs with minimal cling requirements and high vlumetric energy density Standard prpulsin Strategic cling, advanced cling cncepts, etc. Wide gear rati transmissins Diesel Engines Imprved understanding f military relevant fuel cmbustin phenmena Lw and medium temperature chemistry Cld start prgressin Ignitin limits and the impact n engine perfrmance Thermal efficiency augmentatin Frictin, ancillaries, strategic cling, etc. Pwer density cnsideratins Multi-fuel peratin and ptimizatin 11
Current/Recent JP-8 Needs f the Army Addressed by the ARC Evapratin and Spray Penetratin Data/Analysis 0-D mdel develpment: TARDEC (evapratin-warm cnd.) Optical Engine data WSU (cld) CFD: University f Michigan (UM) and Laura Decker (WSU) Multi-zne: University f Michigan-Dearbrn (pending) Ignitin and Generalized Heat Release Analysis Single Cylinder Measurements: TARDEC & WSU Multi-cylinder measurements: TARDEC & WSU & UM Mdeling: TARDEC*, WSU, & UM Laura Decker: zer-dimensinal/reduced mechanisms UM: full kinetics with pssible reductin Fuel Effects Cmbustin Cmpensatin Multi- and single-cylinder: WSU Cld Starting Transient Cmbustin Behavir Multi- and single-cylinder: WSU 12
Army Alternative Fuel Research Needs Addressed by ARC Army Alt Fuels = JP-8 synthetics that are blended r unblended with JP-8 AND ignitin limit fuels Evapratin and Spray Penetratin Data/Analysis 0-D mdel develpment: TARDEC (evapratin-warm cnd.) CFD: Laura Decker (WSU) Ignitin and Generalized Heat Release Analysis Single Cylinder Measurements: TARDEC & WSU Multi-cylinder measurements: WSU & UM (?) Mdeling: TARDEC* & WSU Laura Decker: zer-dimensinal/reduced mechanisms Fuel Effects Cmbustin Cmpensatin Multi- and single-cylinder: nne* Cld Starting Transient Cmbustin Behavir Multi- and single-cylinder: WSU 13
Examples f TA4 Transitins t the Army WSU ignitin data (JP-8/Sasl JP-8) fr internal use UM Series HEV tracked vehicle study fr internal use UM HEV truck cncept study fr internal use WSU clsed lp cntrl study fr internal use CU suspensin energy recvery cncept study fr internal use KEY INGREDIENTS fr TARDEC tech transfer: team level interest (TARDEC) regular interactin with TARDEC engineer supprt frm divisin level leadership KEY POINT: ARC TA4 activities are a small percentage f the GVPM verall external and internal R&D and in-huse test/evaluatin prtfli. Prjects must be very relevant t TARDEC team (engineer) fr any chance f tech transitin. 14