Toyota 2.5L TNGA Prototype Engine from 2016 Aachen Paper - ALPHA Generation Process

This engine represents Toyota's new TNGA gasoline naturally aspirated engines presented at the 25th Aachen Colloquium Automobile and Engine Technology in 2016. The target presented for this engine is over 40% thermal efficiency and a high engine specific power of 60kW/L for vehicles with conventional transmission. The specific data selected for this engine is the 2.5L with 40% peak thermal efficiency, and peak power of approximately 150 kW.

SUGGESTED CITATION:
Toyota 2.5L TNGA Prototype Engine from 2016 Aachen Paper - ALPHA Map Package. Version 2017-12. Ann Arbor MI: US EPA National Vehicle and Fuel Emissions Laboratory, National Center for Advanced Technology, 2017.

Engine Physical Characteristics

Set physical characteristics based on published information Eiji Murase, Rio Shimizu, "Innovative Gasoline Combustion Concepts for Toyota New Global Architecture". 25th Aachen Colloquium Automobile and Engine Technology 2016

engine = [];
engine.name = 'Toyota 2.5L TNGA Prototype Engine from 2016 Aachen Paper';
engine.combustion_type = enum_engine_combustion_type.spark_ignition;
engine.displacement_L = 2.5;
engine.num_cylinders = 4;
engine.compression_ratio = 13;

Efficiency Map Image Data

Import efficiency map image data from "Eiji Murase, Rio Shimizu, 'Innovative Gasoline Combustion Concepts for Toyota New Global Architecture'. 25th Aachen Colloquium Automobile and Engine Technology 2016"

This image was digitized by loading the image into MATLAB and manually tracing the efficiency contours.

load('2016 Toyota 2.5L TNGA efficiency image.mat');

image_data.name = 'Efficiency Map Image';
image_data.speed_rpm = efficiency(:,1);
image_data.torque_Nm = efficiency(:,2) ;
image_data.efficiency_pct = efficiency(:,3);
image_data.fuel_prop = class_REVS_fuel('MTE_GASOLINE'); % Need assumed fuel for Efficiency Input

Additional Fueling Data

Add additional estimated points to provide appropriate trends for high load or high speed extrapolation of the test data. The maximum torque data presented in the paper efficiency map is roughly 180 Nm, while the maximum torque output presented is approximately 250 Nm. Extrapolation of the image efficiency data resulted in high load fuel consumption that is likely too efficient. These additional points represent an estimate of how efficiency would be expected to roll off at high load.

est_data.name = 'Estimated Data';
est_data.speed_rpm = [		800,	900,	1500,	2000,	2500,	3000,	2500,	3000,	4500,	6000,	6500,	6000,	6000,	6000,	4500];
est_data.torque_Nm = [		140,	170,	200,	200,	195,	190,	225,	220,	240,	220,	220,	150,	10,		190,	10];
est_data.efficiency_pct = [	33,		33,		34,		37,		39,		39,		35,		35,		30,		29,		28,		33,		7,		31,		9];
est_data.fuel_prop = class_REVS_fuel('MTE_GASOLINE'); %Need assumed fuel for Efficiency Input

Include estimated idle point, which lies outside the available data. The estimate is from EPA test data of similar engines.

est_idle_data.name = 'Estimated Idle Data';
est_idle_data.speed_rpm = [	650 ];
est_idle_data.torque_Nm = [	8,	];
est_idle_data.fuel_gps =  [	0.20];

Maximum Torque (WOT) Curve Data

Import data from image of maximum torque from Eiji Murase, Rio Shimizu, "Innovative Gasoline Combustion Concepts for Toyota New Global Architecture". 25th Aachen Colloquium Automobile and Engine Technology 2016

This image was digitized by loading the image into MATLAB and manually tracing the maximum torque curve.

load('2016 Toyota 2.5L TNGA WOT image.mat');

max_torque_image_data.speed_rpm = image_WOT(:,1);
max_torque_image_data.torque_Nm = image_WOT(:,2);

% Add Low speed point
max_torque_estimated_data.speed_rpm = 900;
max_torque_estimated_data.torque_Nm = 170;

Minimum Torque (Zero Accelerator Pedal) Curve Data

Utilize a default minimum torque curve which is scaled by engine displacement, since there is no available data.

Fuel Properties

Utilize a default Tier 2 fuel, since no information is available regarding the fuel used for this map.

engine.fuel = class_REVS_fuel('MTE_GASOLINE');
disp(engine.fuel);

  class_REVS_fuel with properties:

                        id: 'MTE_GASOLINE'
               description: 'Gasoline for MTE'
          density_kgpL_15C: 0.74009
      energy_density_MJpkg: 43.309
    carbon_weight_fraction: 0.866
          anti_knock_index: 93
           alcohol_pct_vol: 0
                  gCO2pgal: 8887
    energy_density_BTUplbm: 18619
          specific_gravity: 0.7408

Idle Speed

Estimate based on idle speed observed during benchmarking of several recent vehicles with small turbocharged gasoline engines, 600-700 RPM is typical. 700 RPM was selected to be conservative for this engine's idle fuel consumption.

engine.idle_speed_radps =  650 * convert.rpm2radps ;

Engine Build for Simulation in ALPHA

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, {image_data, est_data, est_idle_data}, 'WOT', { max_torque_image_data, max_torque_estimated_data} , 'image', 'plot_efficiency','no_point_labels');

Idle Fuel Verification

Confirm appropriate fuel consumption near idle conditions. While the result of this check falls slightly outside of the range it is due to the conservative default minimum torque curve creating a higher than expected indicated efficiency.

REVS_check_idle_fuel(engine)

Estimated idle fuel consumption @ 650 RPM & 26.7 Nm: 0.223 g/sec => Indicated Efficiency: 35.1%
Warning: Idle fuel consumption is outside of expected range [0.224 - 0.290] 

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

Use the default adjustment factors during the simulation, since there is no transient fueling data available.

File Description

Generate and write the created ALPHA engine definition into a file for later simulation.

write_REVS_engine( 'engine_2016_toyota_TNGA_2L5_paper_image.m', engine);

Engine Build: engine_toyota_TNGA_2L5_paper_image.m

% ALPHA ENGINE DEFINITION
% Generated 07-Dec-2017 10:47:17

% Constructor
engine = class_REVS_engine();
engine.name =  'Toyota 2.5L TNGA Prototype Engine from 2016 Aachen Paper'; 
engine.source_filename = mfilename;engine.matrix_vintage = enum_matrix_vintage.present;

% Physical Description
engine.displacement_L =  2.5; 
engine.num_cylinders =  4; 
engine.combustion_type = enum_engine_combustion_type.spark_ignition;
engine.compression_ratio =  13; 

% Maximum Torque Curve
engine.full_throttle_speed_radps = [  0.00000000,	;  94.247780,	;  166.79372,	;  209.23546,	;  245.38090,	;  261.93785,	;  289.76595,	;  340.05864,	;  417.71304,	;  444.06423,	;  528.01493,	;  656.03975,	;  689.85323,	;  724.34589,	;  793.33121,	 ]; 
engine.full_throttle_torque_Nm = [  0.00000000,	;  170.00000,	;  210.07180,	;  215.88718,	;  232.97436,	;  237.30598,	;  239.41197,	;  233.69231,	;  249.12821,	;  250.63590,	;  249.77436,	;  229.69573,	;  220.87692,	;  189.32308,	; 0.00000000,	 ]; 

% Minimum Torque Curve
engine.closed_throttle_speed_radps = [  0.00000000,	;  793.33121,	;  837.75804,	 ]; 
engine.closed_throttle_torque_Nm = [  -19.939394,	; -57.047475,	; -58.016913,	 ]; 

% Fuel Map
engine.fuel_map_speed_radps = [  0.00000000,	 52.359878,	 78.539816,	 104.71976,	 130.89969,	 157.07963,	 183.25957,	 209.43951,	 235.61945,	 261.79939,	 287.97933,	 314.15927,	 340.33920,	 366.51914,	 392.69908,	 418.87902,	 471.23890,	 523.59878,	 575.95865,	 628.31853,	 680.67841,	 733.03829,	 785.39816,	 837.75804,	 ]; 
engine.fuel_map_torque_Nm = [  -59.899849,	; -25.949925,	;  8.0000000,	;  18.109829,	;  28.219658,	;  38.329487,	;  48.439316,	;  58.549145,	;  68.658974,	;  78.768803,	;  88.878632,	;  98.988462,	;  109.09829,	;  119.20812,	;  129.31795,	;  139.42778,	;  149.53761,	;  159.64744,	;  169.75726,	;  179.86709,	;  189.97692,	;  200.08675,	;  210.19658,	;  220.30641,	;  230.41624,	;  240.52607,	;  250.63590,	;  263.16769,	 ]; 
engine.fuel_map_gps = [
0.026759874, 0.00000000, 0.00000000, 0.00000000, 0.00000000, 0.00000000, 0.00000000, 0.00000000, 0.00000000, 0.00000000, 0.00000000, 0.00000000, 0.00000000, 0.00000000, 0.00000000, 0.00000000, 0.00000000, 0.00000000, 0.00000000, 0.00000000, 0.00000000, 0.00000000, 0.00000000, 0.00000000, ;
0.086471690, 0.082410079, 0.080370812, 0.078678513, 0.078099824, 0.079655172, 0.084391107, 0.093270794, 0.10708630, 0.12640381, 0.15160237, 0.18288851, 0.22027877, 0.26362591, 0.31270182, 0.36728545, 0.49981498, 0.66363646, 0.83339635, 0.97816437,  1.0765092,  1.1343181,  1.1680939,  1.1930744, ;
0.10409418, 0.16992611, 0.20020291, 0.23076208, 0.26699197, 0.30867142, 0.35397935, 0.40226390, 0.45427978, 0.51139097, 0.57526484, 0.64688796, 0.72505718, 0.80533403, 0.88777779, 0.97401384,  1.1708705,  1.4429999,  1.7386215,  2.0111501,  2.1730143,  2.2969987,  2.4085790,  2.5172882, ;
0.098839226, 0.17872974, 0.21797246, 0.26381022, 0.31964551, 0.37935447, 0.44210171, 0.50594589, 0.56986968, 0.63891027, 0.71563876, 0.79935874, 0.88782707, 0.97568029,  1.0685167,  1.1671389,  1.3908407,  1.6745173,  1.9799788,  2.2629700,  2.4688280,  2.6370538,  2.7912953,  2.9421180, ;
0.092065776, 0.19534374, 0.24796957, 0.30344206, 0.37419182, 0.44867574, 0.52982166, 0.61158701, 0.68804621, 0.77088039, 0.86342936, 0.96106454,  1.0458498,  1.1454794,  1.2516323,  1.3629163,  1.6112103,  1.9056356,  2.2184545,  2.5132817,  2.7617812,  2.9774184,  3.1783091,  3.3751177, ;
0.084739030, 0.21891525, 0.28525317, 0.35055242, 0.42858719, 0.51661799, 0.61284724, 0.71037377, 0.80805710, 0.90949874,  1.0104203,  1.1151244,  1.2150689,  1.3235145,  1.4387374,  1.5601319,  1.8301486,  2.1367351,  2.4582396,  2.7697063,  3.0572063,  3.3211260,  3.5718910,  3.8184067, ;
0.077442379, 0.24478070, 0.32675600, 0.40563769, 0.49330594, 0.59517726, 0.70371291, 0.81634556, 0.92553983,  1.0392874,  1.1547763,  1.2699718,  1.3863955,  1.5045027,  1.6280014,  1.7585477,  2.0488867,  2.3691373,  2.7026494,  3.0353167,  3.3599296,  3.6720212,  3.9750279,  4.2745483, ;
0.071049462, 0.26921417, 0.36701119, 0.46215810, 0.56074316, 0.66886633, 0.78774021, 0.91222276,  1.0381210,  1.1669244,  1.2968116,  1.4238401,  1.5539321,  1.6820316,  1.8167504,  1.9590028,  2.2697235,  2.6045228,  2.9537995,  3.3116275,  3.6736852,  4.0341137,  4.3912134,  4.7465684, ;
0.067089272, 0.29190974, 0.40289030, 0.51349924, 0.62486138, 0.74165489, 0.87035465,  1.0086366,  1.1516244,  1.2958971,  1.4380407,  1.5701852,  1.7076260,  1.8534543,  2.0061480,  2.1637848,  2.4943670,  2.8442957,  3.2130548,  3.5998555,  4.0013469,  4.4111780,  4.8241711,  5.2378722, ;
0.067588094, 0.31568357, 0.44022163, 0.56539539, 0.68889624, 0.81534257, 0.95485951,  1.1077413,  1.2676598,  1.4278581,  1.5795044,  1.7185259,  1.8646848,  2.0302884,  2.2019237,  2.3746584,  2.7231188,  3.0894600,  3.4816056,  3.9013843,  4.3453362,  4.8066313,  5.2776068,  5.7520548, ;
0.075125352, 0.34233943, 0.47891189, 0.61721571, 0.75593032, 0.89685284,  1.0458433,  1.2056116,  1.3722201,  1.5456889,  1.7243715,  1.8854342,  2.0470901,  2.2261718,  2.4091428,  2.5915621,  2.9554802,  3.3410495,  3.7609213,  4.2179241,  4.7079468,  5.2235944,  5.7550366,  6.2926341, ;
0.092090766, 0.37314336, 0.51943122, 0.66895436, 0.81808886, 0.97326933,  1.1393142,  1.3058651,  1.4630092,  1.6420380,  1.8602530,  2.0591351,  2.2505123,  2.4379214,  2.6250408,  2.8123098,  3.1914575,  3.6007612,  4.0530463,  4.5515517,  5.0915631,  5.6650296,  6.2596789,  6.8627503, ;
0.11972674, 0.40978903, 0.56061271, 0.71559749, 0.87442896,  1.0463507,  1.2321715,  1.4155454,  1.5840732,  1.7631531,  1.9674640,  2.1963152,  2.4346064,  2.6426950,  2.8385162,  3.0327862,  3.4322144,  3.8713608,  4.3607806,  4.9047015,  5.4988346,  6.1338786,  6.7943730,  7.4648736, ;
0.15704653, 0.45502476, 0.60734896, 0.76487041, 0.93430104,  1.1190866,  1.3189279,  1.5194682,  1.7067491,  1.8910899,  2.0796131,  2.3242342,  2.5913161,  2.8234394,  3.0377088,  3.2480097,  3.6799085,  4.1566573,  4.6877894,  5.2801705,  5.9328701,  6.6331360,  7.3614862,  8.1005580, ;
0.20082230, 0.51107756, 0.66675932, 0.82632768,  1.0051933,  1.1995981,  1.4051257,  1.6186802,  1.8231876,  2.0233565,  2.2339823,  2.4769134,  2.7386278,  2.9850514,  3.2225028,  3.4576960,  3.9377646,  4.4611483,  5.0386647,  5.6813015,  6.3974487,  7.1657948,  7.9627940,  8.7702684, ;
0.24653585, 0.57499681, 0.74019470, 0.89833814,  1.0832184,  1.2888924,  1.5060064,  1.7297870,  1.9454780,  2.1629571,  2.3919315,  2.6326482,  2.8855594,  3.1435636,  3.4056772,  3.6701462,  4.2106651,  4.7896215,  5.4188469,  6.1127236,  6.8970815,  7.7346173,  8.5993491,  9.4733033, ;
0.28945459, 0.63770832, 0.80744788, 0.97752744,  1.1672596,  1.3797458,  1.6065665,  1.8375849,  2.0668820,  2.3007627,  2.5414910,  2.7804424,  3.0352652,  3.3147170,  3.6040226,  3.8984989,  4.5051554,  5.1468461,  5.8340591,  6.5822978,  7.4365230,  8.3417819,  9.2713663,  10.207821, ;
0.32447168, 0.70354284, 0.88846081,  1.0734580,  1.2671359,  1.4852623,  1.7165917,  1.9483318,  2.1843667,  2.4283335,  2.6807926,  2.9418552,  3.2189181,  3.5170960,  3.8308959,  4.1543301,  4.8284359,  5.5373137,  6.2887786,  7.1047549,  8.0192957,  8.9885952,  9.9781080,  10.970977, ;
0.34817767, 0.77114686, 0.98030008,  1.1867923,  1.3939145,  1.6139133,  1.8399217,  2.0689889,  2.3094671,  2.5649370,  2.8339335,  3.1208221,  3.4267427,  3.7520675,  4.0936541,  4.4466750,  5.1869533,  5.9649703,  6.7842775,  7.6685402,  8.6458488,  9.6753571,  10.717685,  11.759178, ;
0.35894968, 0.83366936,  1.0687678,  1.3008025,  1.5281348,  1.7511521,  1.9738251,  2.2070464,  2.4584670,  2.7260013,  3.0136459,  3.3251354,  3.6631331,  4.0218605,  4.3954640,  4.7798191,  5.5848183,  6.4322265,  7.3205078,  8.2687903,  9.3156236,  10.400443,  11.486738,  12.568466, ;
0.35606684, 0.88618608,  1.1497807,  1.4111318,  1.6666397,  1.9108775,  2.1429115,  2.3837895,  2.6448976,  2.9243312,  3.2318343,  3.5655341,  3.9386037,  4.3316364,  4.7377499,  5.1539027,  6.0232388,  6.9393042,  7.8969404,  8.9081428,  10.027902,  11.159428,  12.280334,  13.394975, ;
0.33968321, 0.92648193,  1.2189842,  1.5105852,  1.8000328,  2.0825792,  2.3374189,  2.5986605,  2.8712717,  3.1688670,  3.5022690,  3.8674550,  4.2637993,  4.6835472,  5.1194332,  5.5667929,  6.5011844,  7.4841768,  8.5109325,  9.6000208,  10.779348,  11.944573,  13.092381,  14.235334, ;
0.31051967, 0.95454754,  1.2755180,  1.5951493,  1.9110949,  2.2189726,  2.5158110,  2.8122956,  3.1198225,  3.4506020,  3.8125252,  4.2059909,  4.6275586,  5.0730583,  5.5372916,  6.0152835,  7.0161073,  8.0629510,  9.1551629,  10.315286,  11.558530,  12.745229,  13.916583,  15.086855, ;
0.26964417, 0.97090144,  1.3198272,  1.6668958,  2.0105647,  2.3500327,  2.6872869,  3.0270644,  3.3776434,  3.7477680,  4.1442644,  4.5684009,  5.0178691,  5.4911066,  5.9846083,  6.4939278,  7.5636003,  8.6691868,  9.8212944,  11.039056,  12.343024,  13.549019,  14.747482,  15.947378, ;
0.21852836, 0.97718260,  1.3549177,  1.7314416,  2.1067242,  2.4819576,  2.8598082,  3.2439189,  3.6393484,  4.0516413,  4.4858318,  4.9434366,  5.4245086,  5.9282395,  6.4526117,  6.9943390,  8.1356604,  9.2939197,  10.501788,  11.772177,  13.093719,  14.346494,  15.581054,  16.814859, ;
0.15930277, 0.97628666,  1.3845661,  1.7931120,  2.2030004,  2.6161583,  3.0351707,  3.4630003,  3.9028902,  4.3581743,  4.8318007,  5.3256548,  5.8406384,  6.3766425,  6.9325836,  7.5063006,  8.7171658,  9.9272580,  11.188950,  12.501820,  13.837515,  15.137076,  16.414407,  17.687101, ;
0.094713852, 0.97137016,  1.4117244,  1.8541047,  2.3002542,  2.7523447,  3.2127059,  3.6836036,  4.1671108,  4.6651096,  5.1792918,  5.7111129,  6.2615235,  6.8307106,  7.4179117,  8.0211194,  9.2831739,  10.561460,  11.877728,  13.226971,  14.582762,  15.923785,  17.246466,  18.561988, ;
0.010712047, 0.96282848,  1.4441718,  1.9297680,  2.4218842,  2.9227696,  3.4343523,  3.9580797,  4.4949280,  5.0455685,  5.6105832,  6.1905565,  6.7859077,  7.3965665,  8.0216666,  8.6594448,  9.9812220,  11.345832,  12.730900,  14.122454,  15.509453,  16.897010,  18.276367,  19.648071, ]; 

% Fuel Properties
engine.fuel = class_REVS_fuel('MTE_GASOLINE');

% 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 = [  0.00000000,	 10.000000,	 ]; 
engine.idle_speed_radps.table = [   68.067841,	;  68.067841,	 ]; 

% Pedal Calibration
engine.pedal_map_type = enum_engine_pedal_map_type.max_engine_power;

% Calibration Adjustment Factors
% -- None --