This document summarizes the process which utilizes EPA's laboratory engine dynamometer and chassis dynamometer test data to generate a full engine fuel consumption map for the Mazda Skyactiv turbocharged 2.5L engine from the 2016 Mazda CX-9 tested on Tier 3 fuel. The generated full engine map defines the complete operating boundaries of the engine which are needed for ALPHA modeling including idle, WOT, minimum torque, and maximum speed.
SUGGESTED CITATION:
2016 Mazda 2.5L Turbo Skyactiv-G Engine Tier 3 Fuel - ALPHA Map Package. Version 2019-02. Ann Arbor MI: US EPA National Vehicle and Fuel Emissions Laboratory, National Center for Advanced Technology, 2019.
Engine Physical Characteristics
Set physical characteristics based on published information:
engine = []; engine.name = '2016 Mazda 2.5L Turbo Skyactiv-G Engine Tier 3 Fuel'; engine.combustion_type = enum_engine_combustion_type.spark_ignition; engine.displacement_L = 2.488; engine.num_cylinders = 4; engine.compression_ratio = 10.5; enigne.bore_mm = 89; % engine.stroke_mm = 100;
Test Data
Import EPA engine dynamameter test data from "2016 Mazda 2.5L Skyactiv Turbo Engine Tier 3 Fuel - Test Data Package. Version 2019-02. Ann Arbor, MI: US EPA, National Vehicle and Fuel Emissions Laboratory, National Center for Advanced Technology, 2019."
test_data = readtable2('4- 2016 Mazda 2.5L Turbo Skyactiv-G Engine Tier 3 Fuel - Test Data.xlsx','Sheet','Steady State','VariableNamesLine',4,'VariableUnitsLine',5,'DataLine',6); ss_test_data.name = 'SS Test Data'; ss_test_data.speed_rpm = test_data.Speed; ss_test_data.torque_Nm = test_data.Torque; ss_test_data.fuel_gps = test_data.FuelMeterFlow; ss_test_data.manifold_press_kPaA = test_data.IntakeManifoldPress; test_data = readtable2('4- 2016 Mazda 2.5L Turbo Skyactiv-G Engine Tier 3 Fuel - Test Data.xlsx','Sheet','High Load Initial','VariableNamesLine',4,'VariableUnitsLine',5,'DataLine',6); hl_test_data.name = 'High Load Test Data'; hl_test_data.speed_rpm = test_data.Speed; hl_test_data.torque_Nm = test_data.Torque; hl_test_data.fuel_gps = test_data.InjectorFuelFlow; hl_test_data.manifold_press_kPaA = test_data.IntakeManifoldPress; test_data = readtable2('4- 2016 Mazda 2.5L Turbo Skyactiv-G Engine Tier 2 Fuel - Test Data.xlsx','Sheet','Steady State with Transmission','VariableNamesLine',4,'VariableUnitsLine',5,'DataLine',6); ls_test_data.name = 'Low Speed Test Data'; ls_test_data.speed_rpm = test_data.Speed; ls_test_data.torque_Nm = test_data.Torque; ls_test_data.fuel_gps = test_data.FuelMeterFlow; ls_test_data.manifold_press_kPaA = test_data.IntakeManifoldPress;
Maximum Torque (WOT) Curve Data
Maximum torque data is included in the Engine Test Data package referenced above; add maximum power data from: Okita, R., "Mazda SKYACTIV-G Enginewith New Boosting Technology," ACC Symposium 9/28/2016, 2016.
wot_data.speed_rpm = [ 1000, 1250, 1500, 3500, 4000, 4500, 5000, 5400]; wot_data.torque_Nm = [ 250, 350, 400, 404, 391, 375, 356, 308];
Minimum Torque (Zero Accelerator Pedal) Curve Data
Minimum torque data is included in the Engine Test Data package referenced above.
Fuel Properties
Load fuel properties provided in the Fuel Analysis Report identified in the Engine Test Data package referenced above.
engine.fuel = class_REVS_fuel('FTAG 26781');
disp(engine.fuel)
class_REVS_fuel with properties:
id: 'FTAG 26781'
description: 'Tier 3 Cert'
density_kgpL_15C: 0.74326
energy_density_MJpkg: 41.954
carbon_weight_fraction: 82.99
research_octane_number: 92
motor_octane_number: 84
alcohol_pct_vol: 9.66
gCO2pgal: 8.5557e+05
energy_density_BTUplbm: 18037
specific_gravity: 0.74397
Idle Speed
Set estimated idle speed using preliminary EPA chassis dynamometer test data for the 2017 Mazda CX-9; EPA published report pending.
engine.idle_speed_radps = 545 * convert.rpm2radps ;
Build Fuel Map
Construct simulation input for the engine, combining all of the above inputs. Fit the fueling data onto a grid for simple interpolation and establish points that represent the maximum and minimum engine torque versus speed. Confirm the quality of fit between the input data and the resulting engine description by examining the resulting plots.
engine = REVS_build_engine(engine, {ss_test_data, hl_test_data, ls_test_data}, 'WOT',wot_data,'plot_bsfc','plot_efficiency');
Idle Fuel Verification
Confirm appropriate fuel consumption near idle conditions. The following conditions represent idle observed during chassis testing, with engine torque estimated from CAN data and estimates of accessory load. The speeds and fuel flow agree with measurements recorded on this engine. However, in general, idle speeds and fueling depend on the drivetrain the engine is coupled to and may change depending on the application.
% Idle @ 555 RPM in drive measured fuel rate ~0.148 g/sec
engine.interp_fuel_gps( 545 * convert.rpm2radps, 4.3);
0.15186
Fuel Map Linearity
Confirm expected trends in output fuel map, specifically in regions where data is unavailable.
REVS_plot_engine_fuel_linearity(engine);
Model Calibration Options
Calibrate additional properties of the REVS engine model which can be set to match observed behaviors during the validation process.
Note: Default values are used unless properties are specified below, which are derived from the composite set of EPA testing and model validation activities.
Accelerator Pedal Map
Apply default pedal mapping for passenger cars, which will linearly increase engine power with accelerator pedal position.
engine.pedal_map_type = enum_engine_pedal_map_type.max_engine_power;
Transient Fueling Adjustments
Utilize the default adjustment factors during the simulation, since there is no transient fueling data available.
File Description
Generate and write the created REVS engine definition into a file for later simulation.
write_REVS_engine( 'engine_2016_Mazda_Skyactiv_Turbo_2L5_Tier3.m', engine);
Engine Build: engine_2016_Mazda_Skyactiv_Turbo_2L5_Tier3.m
% ALPHA ENGINE DEFINITION % Generated 06-Feb-2019 15:43:23 % Constructor engine = class_REVS_engine(); engine.name = '2016 Mazda 2.5L Turbo Skyactiv-G Engine Tier 3 Fuel'; engine.source_filename = mfilename;engine.matrix_vintage = enum_matrix_vintage.present; % Physical Description engine.displacement_L = 2.488; engine.num_cylinders = 4; engine.combustion_type = enum_engine_combustion_type.spark_ignition; engine.compression_ratio = 10.5; % Maximum Torque Curve engine.full_throttle_speed_radps = [ 0.00000000000000000 ; 102.73007977238623 ; 104.71975511965977 ; 130.89969389957471 ; 157.23299275802555 ; 183.31193133696442 ; 235.77706844446610 ; 261.97161724411779 ; 314.36566951399777 ; 366.76880088572489 ; 419.35968415463833 ; 471.23889803846896 ; 523.59877559829886 ; 549.77871437821386 ; 575.95865315812875 ]; engine.full_throttle_torque_Nm = [ 0.00000000000000000 ; 195.83900000000000 ; 250.00000000000000 ; 350.00000000000000 ; 413.45792349726713 ; 441.41744186046486 ; 456.70876288659787 ; 445.02081218274100 ; 436.76956521739152 ; 412.82608695652215 ; 403.16599999999954 ; 375.00000000000000 ; 356.00000000000000 ; 305.14285714285717 ; 0.00000000000000000 ]; engine.naturally_aspirated_speed_radps = [ 0.00000000000000000 ; 135.17128871717952 ; 157.17441766370519 ; 209.54162003779624 ; 288.08933194346207 ; 575.95865315812875 ]; engine.naturally_aspirated_torque_Nm = [ 169.21809559869203 ; 147.80915108669063 ; 161.95618085347002 ; 168.62363775209255 ; 170.28538773104546 ; 148.55532620831710 ]; % Minimum Torque Curve engine.closed_throttle_speed_radps = [ 0.00000000000000000 ; 102.73007977238623 ; 366.62386267392884 ; 523.70349535341848 ; 575.95865315812875 ]; engine.closed_throttle_torque_Nm = [ -20.671108208955221 ; -24.855000000000000 ; -33.299999999999997 ; -42.000000000000000 ; -44.128197761194031 ]; % Fuel Map engine.fuel_map_speed_radps = [ 0.00000000000000000 ; 36.462109735726543 ; 72.924219471453085 ; 80.477131809458527 ; 85.974918953240675 ; 105.61717906760384 ; 135.17128871717952 ; 157.17441766370519 ; 183.36070312216003 ; 209.54162003779624 ; 235.73193639134223 ; 261.91028383956564 ; 288.08933194346207 ; 314.27333683296115 ; 340.45825397771523 ; 366.64317112246931 ; 392.82701732133251 ; 419.01086352019576 ; 445.19950115631622 ; 471.38813879243668 ; 497.54581707292755 ; 523.70349535341848 ; 549.83107425577361 ; 575.95865315812875 ]; engine.fuel_map_torque_Nm = [ -46.334607649253734 ; -30.377964285714285 ; -10.550646616541353 ; 9.2766710526315777 ; 32.726646153846147 ; 49.809107960643992 ; 66.891569767441837 ; 89.911650000000009 ; 120.41429166666666 ; 145.79293749999999 ; 165.22936111111113 ; 190.66894676240872 ; 207.00939924813406 ; 223.34985173385937 ; 249.53718750000002 ; 259.28802631578947 ; 279.43949334785111 ; 299.94660402843709 ; 322.77119787943997 ; 350.11348956621293 ; 366.43844965313741 ; 393.08993412111670 ; 409.88159400301146 ; 435.59460096115879 ; 456.70876288659787 ; 479.54420103092781 ]; engine.fuel_map_gps = [ 0.13315270302379262 0.030806969519652061 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.00000000000000000 ; 0.12116256044198817 0.070415924038043309 0.017540600657032140 0.0062252913273141645 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.00000000000000000 0.0079471503668642925 0.019654902182739336 0.038583646316067505 0.066031190854002136 0.10762500144915363 0.15936450364731392 0.22261357703478452 0.28794983468706115 0.35334316830263740 0.41595736145944473 0.47786776735473557 0.53879757934510797 ; 0.10341083227097263 0.11260424693737296 0.11776535353785231 0.11630258742877693 0.11527735086790172 0.11312400236206499 0.13429655462626500 0.15656119984160402 0.18640193452419451 0.22567932102661731 0.27202992813924431 0.32233911932372722 0.36524876370877402 0.39870053873879940 0.44192327811540499 0.50325614461607060 0.58449195511563790 0.68408759731278090 0.79033644847167261 0.90594807948326950 0.99992314103592206 1.0958341671279939 1.1627475408221772 1.2298972670815882 ; 0.079011647920116418 0.13574612916899256 0.18580227276053365 0.19677048032654310 0.20481155058891473 0.23468494549293190 0.29260709672496299 0.33786345033050064 0.39307431226857076 0.46243118729909882 0.53574217594995954 0.61284784595253539 0.68769852915312946 0.75235956838523743 0.82814981569541113 0.92288822971761486 1.0347098925823239 1.1628629719131016 1.2926186306035830 1.4259723600313812 1.5542200469395038 1.6749784494828623 1.7931619275173754 1.9067735731395210 ; 0.039590144827930225 0.15367825828462620 0.26301605180934229 0.28495526802879512 0.30095278149422156 0.35872437567252030 0.45219837815403535 0.52442781772551517 0.61322033468694270 0.71577280890588013 0.81852057115612042 0.91699792964976490 1.0223684040845156 1.1376490515556985 1.2613520671476046 1.3916125123309864 1.5323992034458109 1.6769937559300334 1.8351633383087982 1.9931141091774724 2.1650801242334023 2.3344482011777377 2.5067774835228351 2.6767945143652496 ; 0.0072561986953274329 0.16501480751729478 0.31844609395021539 0.34964354790898139 0.37232005389493628 0.45264126865592214 0.57035668578642984 0.66000733007364809 0.77476348737106182 0.90361999949190486 1.0308566928222336 1.1546803713262366 1.2884382277155970 1.4325037365984581 1.5842814496606668 1.7395539065339256 1.9067378838266280 2.0774972854332674 2.2522642234256627 2.4323595330625576 2.6286029250659495 2.8279416054053730 3.0245977365217747 3.2207831511763150 ; 0.00000000000000000 0.17734996807401224 0.37528630240161104 0.41533636660407425 0.44441391752249321 0.54713567153478970 0.69266853221136881 0.80265370239967704 0.94235971013450426 1.0939843079944156 1.2500153240605731 1.4060220186311985 1.5686014762740623 1.7400643488016894 1.9171632461914032 2.0991866285281602 2.2876033962326332 2.4824773404527822 2.6799368330685502 2.8876908946635247 3.1030184393550582 3.3231389786347569 3.5412735740576062 3.7568063174657316 ; 0.00000000000000000 0.20585208727668830 0.45439340384065213 0.50624973798014328 0.54391775975546575 0.67724514696325588 0.86709465133824049 1.0073213845973739 1.1784009964052105 1.3629157658326450 1.5591053134757396 1.7589272869278130 1.9616977131075521 2.1666898716681984 2.3653177663433196 2.5747507732147867 2.7904123287581144 3.0183484323868814 3.2452656581149339 3.4867225911638546 3.7414488620897415 4.0015768679220516 4.2392850682604379 4.4729542340104640 ; 0.00000000000000000 0.27408527619705547 0.57491559005398873 0.64060764217277555 0.68846659848719238 0.85962748873688333 1.1070029898144214 1.2768403332186020 1.4750534159229296 1.6785130939414050 1.9094842820680655 2.1515175207083250 2.3962509656664555 2.6446424036963676 2.8828179352448844 3.1231750732708701 3.3874375523986915 3.6620134733937220 3.9420877951980500 4.2320617287739051 4.5426930272351367 4.8554296337068239 5.1562565410158649 5.4528789153564832 ; 0.058921454526628871 0.38460696810697875 0.71668377336867439 0.78585071303582443 0.83623495760606847 1.0171628724295101 1.3090230234740097 1.5135768208759044 1.7325766934930744 1.9551847745086579 2.2063110136545765 2.4814653016275687 2.7674431108094844 3.0544547009202279 3.3355652098356496 3.6247735542704986 3.9301440123368705 4.2506942277764734 4.5812049548885403 4.9273752340393484 5.2806661708398250 5.6459442399748943 6.0156809331829297 6.3851564117223649 ; 0.20243322374364642 0.52871303797291991 0.87277680339932984 0.94770778832949187 1.0025105489712818 1.2019245133639151 1.5207430066106342 1.7350071985683699 1.9689806546216602 2.2254233132338253 2.4977062587950618 2.7897909414045095 3.0849404273806869 3.3936377429666944 3.6986297998741460 4.0213682512708573 4.3830925990409852 4.7536567085623354 5.1204515962141279 5.4847980353523020 5.9089874706025576 6.3397390202843020 6.7746991658961813 7.2077001821986029 ; 0.48128137466109239 0.80518625924159826 1.1533707228907186 1.2324248705692926 1.2905291943275867 1.5070646154770575 1.9011000114741035 2.1177982749306494 2.3752239765707612 2.6266854698029838 2.9192906359120521 3.2249836932624589 3.5391880839322600 3.8806330351726670 4.2213030102811135 4.5967289890437195 5.0544795427716371 5.5305989970401468 5.9602911135672327 6.4057553058480954 6.8823545905357726 7.4051292972888287 7.9353009650330968 8.4788696627231488 ; 0.70581221554535245 1.0392477381021390 1.3893486210764550 1.4664373988317241 1.5229003661326717 1.7299373101959055 2.0785747298952781 2.3137702050269398 2.6034734952479681 2.8993501084540405 3.2103841727428124 3.5237783967059575 3.8556995196837298 4.2198424876232314 4.6028593373097912 5.0222850008775151 5.5068898342979011 6.0002460436273610 6.4693322349431615 6.9611183770809602 7.5109243774622438 8.1250150186988197 8.7774236680235784 9.4466302815274705 ; 0.94970424019500521 1.2994907258500574 1.6516663701555607 1.7255485130890635 1.7794038108476180 1.9730064277430583 2.2744841920050112 2.5069280640361566 2.8244792225777706 3.1686594159486194 3.5091961411699719 3.8392688150070184 4.1939264983711686 4.5839133098033722 5.0081056156436148 5.4657047648494643 5.9640256523046302 6.4827272573437851 6.9634500019538272 7.5102592521287832 8.1631258788012175 8.9050881248084419 9.6987831288359523 10.510488090495588 ; 1.3583766062382701 1.7455350076533438 2.1127449281449309 2.1836140545583014 2.2348334391558944 2.4129721629542957 2.6626481295414135 2.8664220013583805 3.1972206683126032 3.5781259298522237 3.9793768225014770 4.3750788205799749 4.7846717682299156 5.2217269028364104 5.6798358981822625 6.1531533184888394 6.6246953044076538 7.1600277430995769 7.7542960126848399 8.4975433435629011 9.4141173501873112 10.415117784285638 11.430433331694864 12.440524216153207 ; 1.4997552218315409 1.8991024432757448 2.2800804778650874 2.3541950068216586 2.4077752872026150 2.5938045638361471 2.8367102759681315 3.0125201514237498 3.3518559758114668 3.7343990495195944 4.1601621638978106 4.5830715812590563 5.0123635064361300 5.4531913265886214 5.9087350982404656 6.3947101756769413 6.8590678336225972 7.4250303774109385 8.1374294155337150 8.9860198833360219 10.016543628953245 11.085656034799145 12.141113969137182 13.183096678262434 ; 1.7714468311765945 2.1924677961943821 2.6091832957976884 2.6951753515407981 2.7577271680484734 2.9798658547250705 3.2718663382408777 3.3507181071882304 3.6826857638110431 4.0545031282317225 4.5373460554713168 5.0294672702871841 5.4905613541993077 5.9158161727258793 6.3437312675786703 6.8187855680392184 7.3737131049579494 8.0732668956732283 9.1426055324630937 10.281430694127200 11.488030568041601 12.617841690284912 13.687232078601326 14.736017861397208 ; 2.0012940149260467 2.4390516408646881 2.8813905833490270 2.9714028704735242 3.0367227065962328 3.2659597663350382 3.5480054039248490 3.6672693133454977 4.0310311367780711 4.4498804789891597 4.9934061040981685 5.5365118340313026 5.9827547839413340 6.3504718216372842 6.8448889665740600 7.4822431749221430 8.3229190312467036 9.3714607480840684 10.768069521798722 12.219414927906280 13.299513640532041 14.301030833286486 15.305941147775664 16.320888941933209 ; 2.1912217221316035 2.6356264002992154 3.0818667077037372 3.1750897399730325 3.2429876646324383 3.4856469905345326 3.8310319616977675 4.0163830138124466 4.3785262723875107 4.8894131378848114 5.5479907171745868 6.0869274960372755 6.5279822551168474 6.9598095454868156 7.6796139553656957 8.6592121491319123 9.9024732007454990 11.312535657005011 12.648434318037996 13.945330702187777 15.044072514253017 16.071857967408111 17.090481262960640 18.115324574142612 ; 2.2939306352853301 2.7684292710979506 3.2184138242937794 3.3081013274804767 3.3731773614979956 3.6035500797208604 3.9611976307514638 4.2822134503391647 4.7702410651051235 5.4362625778147882 6.2243854207224167 6.9511953736286296 7.6416998060666339 8.2320534049039509 9.2416325168279414 10.472539744510430 11.865075712661977 13.236982337509057 14.451137348738435 15.570155481522820 16.789679181298329 17.988245850681949 19.152960102669606 20.303041157592720 ; 2.2870561462942689 2.8081009300305873 3.3004614583392056 3.3972451678165299 3.4673655097173723 3.7141677575780694 4.0920108003225684 4.4418298238768914 4.9904366472419222 5.7709839997450629 6.5489258988066261 7.4872639622568471 8.3745903858326063 9.2837383584459783 10.391636099761824 11.688377054624409 13.073228193927557 14.409067685053305 15.608551048086396 16.744777953637310 17.937912671366984 19.161813933955223 20.384989566809544 21.602160010435437 ; 2.1750209910758311 2.8149454603480821 3.4504670280144785 3.5799356017213153 3.6739822562230069 4.0067608657313922 4.4755114796771158 4.8030305769464778 5.2901660468631526 6.3066503879353828 7.2389647123195715 8.3607987515847206 9.5848368026832773 10.855771252123507 12.181183383380599 13.570026208464698 14.972009210961142 16.366487080671302 17.526888485953958 18.689134966389155 19.900474800297498 21.157223642751926 22.438920171033850 23.729907709190776 ; 2.0691932686195673 2.7959595552926717 3.5366626158276464 3.6938580411436650 3.8085682162611412 4.2225260357719581 4.8692558042110532 5.3373692121121898 5.7398060795889361 6.5730714854317664 7.6068317369112988 8.8429350112261869 10.249725269227817 11.660998064005431 13.063461051852808 14.465793533992189 15.838221193895446 17.166133836808015 18.508677448543331 19.815938869417902 21.115154295738751 22.431830979210091 23.766744731285346 25.111558159924925 ; 1.8860352462211400 2.7600215555487941 3.6608970067582627 3.8529890632357957 3.9932015436857817 4.4995179994583268 5.2933806163291610 5.9049056946847003 6.6458659977830798 7.5333455864086432 8.1809319768218707 9.3292902236612516 10.886597995334061 12.534442901572527 14.040527291045414 15.497381252072355 16.975920395878546 18.456319387961390 19.948454940873312 21.435698047346435 22.908502154854993 24.373080891291874 25.834212651589475 27.296061189305703 ; 1.7459766884000405 2.7412410111332988 3.7505635595963724 3.9621870200302811 4.1164064862529761 4.6698426033686191 5.5169898176386196 6.1574721257508518 6.9290076463241315 7.7300788368683735 8.5898644313184587 9.7918629477524437 11.311667982596541 12.957951039766467 14.606671125338236 16.233651934029258 17.856465368632005 19.483307513283929 21.112775214046216 22.738145827087813 24.351022186818387 25.952031193541316 27.542903772072542 29.130416519241678 ; 1.6058732957260129 2.7287549135829723 3.8393549702763692 4.0669179675047662 4.2323904184309944 4.8213365315487176 5.6987404908908186 6.3586455646073068 7.1739253050000729 8.0773130555729207 9.1399266976898712 10.392818496027475 11.837422808790803 13.446149782278523 15.171939919089318 16.959189484096829 18.765779496257068 20.570063902533068 22.363002943997454 24.141775826852019 25.904413996705113 27.654566497820465 29.393693631719142 31.128719121302296 ]; % Fuel Properties engine.fuel = class_REVS_fuel('FTAG 26781'); % Idle Speed engine.idle_speed_radps = class_REVS_dynamic_lookup; engine.idle_speed_radps.axis_1.signal = 'veh_spd_mps'; engine.idle_speed_radps.axis_1.breakpoints = [ 0.00000000000000000 10.000000000000000 ]; engine.idle_speed_radps.table = [ 57.072266540214571 ; 57.072266540214571 ]; % Pedal Calibration engine.pedal_map_type = enum_engine_pedal_map_type.max_engine_power; % Calibration Adjustment Factors % -- None --