ANNEX VVERIFYING ENGINE DATA

Appendix 8

Important evaluation steps and equations of the engine pre-processing tool

This Appendix describes the most important evaluation steps and underlying basic equations that are performed by the engine pre-processing tool. The following steps are performed during evaluation of the input data in the order listed:

1.Reading of input files and automatic check of input data

1.1

Check of requirements for input data according to the definitions in paragraph 6.1 of this Annex

1.2

Check of requirements for recorded FCMC data according to the definitions in paragraph 4.3.5.2 and subpoint (1) of paragraph 4.3.5.5 of this Annex

2.

Calculation of characteristic engine speeds from full load curves of parent engine and actual engine for certification according to the definitions in paragraph 4.3.5.2.1 of this Annex

3.Processing of fuel consumption (FC) map

3.1

FC values at nidle are copied to engine speed (nidle – 100 min– 1) in the map

3.2

FC values at n95h are copied to engine speed (n95h + 500 min– 1) in the map

3.3

Extrapolation of FC values at all engine speed setpoints to a torque value of (1.1 times Tmax_overall) by using least squares linear regression based on the 3 measured FC points with the highest torque values at each engine speed setpoint in the map

3.4

Adding of FC = 0 for interpolated motoring torque values at all engine speed setpoints in the map

3.5

Adding of FC = 0 for minimum of interpolated motoring torque values from subpoint (3.4) minus 100 Nm at all engine speed setpoints in the map

4.Simulation of FC and cycle work over WHTC and respective subparts for actual engine for certification

4.1.

WHTC reference points are denormalized using the full load curve input in originally recorded resolution

4.2.

FC is calculated for WHTC denormalized reference values for engine speed and torque from subpoint 4.1

4.3.

FC is calculated with engine inertia set to 0

4.4.

FC is calculated with standard PT1-function (as in main vehicle simulation) for engine torque response active

4.5.

FC for all motoring points is set to 0

4.6.

FC for all non-motoring engine operation points is calculated from FC map by Delaunay interpolation method (as in main vehicle simulation)

4.7.

Cycle work and FC are calculated according to equations defined in paragraphs 5.1 and 5.2 of this Annex

4.8.

Simulated specific FC values are calculated analogous to equations defined in paragraphs 5.3.1 and 5.3.2 of this Annex for measured values

5.Calculation of WHTC correction factors

5.1.

Measured values from input to pre-processing tool and simulated values from point (4) are used in accordance with the equations in points (5.2) to (5.4)

5.2.

CFUrban = SFCmeas,Urban/SFCsimu,Urban

5.3.

CFRural = SFCmeas,Rural/SFCsimu,Rural

5.4.

CFMW = SFCmeas,MW/SFCsimu,MW

5.5.

In case that the calculated value for a correction factor is lower than 1, the respective correction factor is set to 1

6.Calculation of cold-hot emission balancing factor

6.1.

This factor is calculated in accordance with the equation in point (6.2)

6.2.

BFcold-hot = 1 + 0,1 × (SFCmeas,cold – SFCmeas,hot)/SFCmeas,hot

6.3.

In case that the calculated value for this factor is lower than 1, the factor is set to 1

7.Correction of FC values in FC map to standard NCV

7.1.

This correction is performed in accordance with the equation in point (7.2)

7.2.

FCcorrected = FCmeasured,map × NCVmeas/NVCstd

7.3.

FCmeasured,map shall be the FC value in the FC map input data processed in accordance with point (3)

7.4.

NCVmeas and NVCstd shall be defined in accordance with paragraph 5.3.3.1 of this Annex

7.5.

In the case that reference fuel of the type B7 (Diesel / CI) in accordance with paragraph 3.2 of this Annex was used during testing, the correction in accordance with points (7.1) to (7.4) is not performed.

8.Converting of engine full load and motoring torque values of the actual engine for certification to a logging frequency of the engine speed of 8 min– 1

F18.1.

If the average logging frequency of the engine speed of the originally recorded full load curve is smaller than 6, the conversion is performed by arithmetical averaging over intervals of ± 4 min– 1 of the given setpoint for the output data based on the full load curve input in originally recorded resolution. If the average logging frequency of the engine speed of the originally recorded full load curve is greater than or equal to 6, the conversion is performed by linear interpolation based on the full load curve input in originally recorded resolution.