The rolling noise calculations each generate a collection of output files, which are used in plotting data in Train Noise Expert, and also as input data for external noise calculations. Some of this data may be of interest to users, and a description of the data contents for some of the most useful files is provided here.
The following files can be found in: [ProjectFolder]/Results/[Date]/Rolling/[Situation]/[Wheelset]
Sound power results are provided for a single wheel, and in the case of rail/sleeper, this is evaluated over the median Vehicle length in the Situation.
n.b. Files with a ‘_1’ suffix indicate that they contain values for unit roughness (dB re 10-6m), but otherwise have the same structure as the corresponding file without the ‘_1’ suffix.
| File: | roll_total_SWL.csv |
|---|---|
| Description: | Total rolling sound power level, in dB re 10-12W. |
| Data: | Column 1: 1⁄3 octave frequency bands (Hz) Column 2: total power |
| File: | roll_wheel_SWL.csv |
|---|---|
| Description: | Sound power levels from the wheel, in dB re 10-12W. |
| Data: | Column 1: 1⁄3 octave frequency bands (Hz) Column 2: total power Column 3: power from axial motion Column 4: power from radial motion Column 5: power from torsional motion |
| File: | roll_rail_SWL.csv |
|---|---|
| Description: | Sound power levels from the rail, in dB re 10-12W. |
| Data: | Column 1: 1⁄3 octave frequency bands (Hz) Column 2: total power Column 3: power from vertical propagating wave Column 4: power from vertical decaying wave Column 5: power from lateral propagating wave Column 6: power from lateral decaying wave |
| File: | roll_sleeper_SWL.csv |
|---|---|
| Description: | Sound power levels from the sleeper, in dB re 10-12W. (This is for vertical excitation only.) |
| Data: | Column 1: 1⁄3 octave frequency bands (Hz) Column 2: total power |
The following files can be found in: [ProjectFolder]/Results/[Date]/Rolling/[Situation]/[Wheelset]/[Receiver]
Sound pressure results are provided on the basis of the median number of Wheelsets of that type per Vehicle in the Situation, and is evaluated over the median Vehicle length.
Whether the sound pressure includes sound from the left side only or from both sides, is dependent on your Situation settings.
| File: | roll_total.csv |
|---|---|
| Description: | Total rolling sound pressure level, in dB re 2x10-5Pa. |
| Data: | Column 1: 1⁄3 octave frequency bands (Hz) Column 2: total sound pressure level |
| File: | roll_wheel.csv |
|---|---|
| Description: | Sound pressure levels from the wheel(s), in dB re 2x10-5Pa. |
| Data: | Column 1: 1⁄3 octave frequency bands (Hz) Column 2: total sound pressure level Column 3: SPL from axial motion Column 4: SPL from radial motion Column 5: SPL from torsional motion |
| File: | roll_rail.csv |
|---|---|
| Description: | Sound pressure levels from the rail(s), in dB re 2x10-5Pa. |
| Data: | Column 1: 1⁄3 octave frequency bands (Hz) Column 2: total sound pressure level Column 3: SPL from vertical propagating wave Column 4: SPL from vertical decaying wave Column 5: SPL from lateral propagating wave Column 6: SPL from lateral decaying wave |
| File: | roll_sleep.csv |
|---|---|
| Description: | Sound pressure levels from the sleepers, in dB re 2x10-5Pa. |
| Data: | Column 1: 1⁄3 octave frequency bands (Hz) Column 2: sound pressure level |
The following files can be found in: [ProjectFolder]/Results/[Date]/Rolling/[Situation]/[Wheelset]
| File: | roll_wfrs.csv |
|---|---|
| Description: | Wheel mobility, in m/s/N. These are provided as complex numbers. |
| Data: | Column 1: frequencies (Hz) Column 2: vertical mobility Column 3: cross mobility Column 4: lateral mobility |
| File: | roll_cfrs.csv |
|---|---|
| Description: | Contact mobility, in m/s/N. These are provided as complex numbers. |
| Data: | Column 1: frequencies (Hz) Column 2: vertical mobility Column 3: lateral mobility |
| File: | roll_rfrs.csv |
|---|---|
| Description: | Rail mobility, in m/s/N. These are provided as complex numbers. |
| Data: | Column 1: frequencies (Hz) Column 2: vertical mobility Column 3: cross mobility Column 4: lateral mobility |
| File: | roll_contactFilter.csv |
|---|---|
| Description: | The contact filter used in the calculations, in dB. |
| Data: | Column 1: 1⁄3 octave frequency bands (Hz) Column 2: contact filter |
| File: | roll_TDRcalc.csv |
|---|---|
| Description: | The calculated track decay rate, in dB/m. (Calculated from track parameters.) |
| Data: | Column 1: frequency (Hz) Column 2: vertical TDR Column 3: lateral TDR |
| File: | roll_rail_vib.csv |
|---|---|
| Description: | The rail velocity response, in m/s. |
| Data: | Column 1: frequency (Hz) Column 2: vertical velocity Column 3: lateral velocity |
| File: | roll_sleeper_vib.csv |
|---|---|
| Description: | The sleeper velocity response, in m/s. |
| Data: | Column 1: frequency (Hz) Column 2: vertical velocity |
For advanced users using Matlab, output data can be found in the calculation’s ‘TNEroll_data.mat’ file. Pertinent parameters provided within the ‘out’ variable within this file are as follows (in which ‘Nf’ is a number of frequency points and ‘Nr’ is number of receivers):
| Variable: | Description: |
|---|---|
| out.rail.rmfrq | The frequencies for the rail mobility data (Hz). |
| out.rail.rwno | The complex rail wavenumbers. (Nf,4) array of data: (Nf,1) vertical propagating, (Nf,2) vertical decaying, (Nf,3) lateral propagating, (Nf,4) lateral decaying. |
| out.rail.rfrs | The rail mobility in m/s/N. (Nf,3) array of data: (Nf,1) vertical mobility, (Nf,2) cross mobility, (Nf,3) lateral mobility. |
| out.rail.rfrw | The rail mobility in m/s/n, per wave type. (Nf,8) array of data: (Nf,1) vertical propagating due to vertical force, (Nf,2) vertical decaying due to vertical force, (Nf,3) vertical propagating due to lateral force, (Nf,4) vertical decaying due to lateral force, (Nf,5) lateral propagating due to vertical force, (Nf,6) lateral decaying due to vertical force, (Nf,7) lateral propagating due to lateral force, (Nf,8) lateral decaying due to lateral force. |
| out.rail.rarad | Struct data holding the rail radiation terms. |
| out.rail.rarad.fr | The frequencies for the rail radiation data (Hz). |
| out.rail.rarad.rprs | The rail sound pressure levels (dB re 2 x 10-5Pa). (Nf,Nr) array of data. |
| out.rail.rarad.rprswave | The rail sound pressure levels (dB re 2 x 10-5Pa), per wave type. (Nf,Nr,4) array of data: (Nf,Nr,1) vertical propagating, (Nf,Nr,2) vertical decaying, (Nf,Nr,3) lateral propagating, (Nf,Nr,4) lateral decaying. |
| out.rail.rarad.rpow | The rail sound power levels (dB re 1 x 10-12W). (Nf,5) array of data: (Nf,1) total, (Nf,2) vertical propagating, (Nf,3) vertical decaying, (Nf,4) lateral propagating, (Nf,5) lateral decaying. |
| out.wheel.wmfrq | The frequencies for the wheel mobility data (Hz). |
| out.wheel.wfrs | The wheel mobility in m/s/N. (Nf,3) array of data: (Nf,1) vertical mobility, (Nf,2) cross mobility, (Nf,3) lateral mobility. |
| out.wheel.whrad | Struct data holding the wheel radiation terms. |
| out.wheel.whrad.fw | The frequencies for the wheel radiation data (Hz). |
| out.wheel.whrad.wprs | The wheel sound pressure levels (dB re 2 x 10-5Pa). (Nf,Nr) array of data. |
| out.wheel.whrad.wprssep | The wheel sound pressure levels (dB re 2 x 10-5Pa), per motion type. (Nf,Nr,4) array of data: (Nf,Nr,1) total, (Nf,Nr,2) axial motion, (Nf,Nr,3) radial motion, (Nf,Nr,4) rotational motion. |
| out.wheel.whrad.wpow | The wheel sound power levels (dB re 1 x 10-12W). (Nf,4) array of data: (Nf,1) total, (Nf,2) axial motion, (Nf,3) radial motion, (Nf,4) rotational motion. |
| out.sleeper.Y1 | The sleeper point mobility in m/s/N. |
| out.sleeper.Yavg | The sleeper average mobility in m/s/N. |
| out.sleeper.slrad | Struct data holding the sleeper radiation terms. |
| out.sleeper.slrad.fs | The frequencies for the sleeper radiation data (Hz). |
| out.sleeper.slrad.sprs | The sleeper sound pressure levels (dB re 2 x 10-5Pa). (Nf,Nr) array of data. |
| out.sleeper.slrad.spow | The sleeper sound power levels (dB re 1 x 10-12W). |
| out.int.frq | The frequencies for the wheel-rail interaction data (Hz). |
| out.int.intf | The contact force (N). (Nf,2) array of data: (Nf,1) vertical, (Nf,2) lateral. |
| out.int.cfrs | The contact mobility (m/s/N). (Nf,2) array of data: (Nf,1) vertical, (Nf,2) lateral. |
| out.int.cfrs | The contact mobility (m/s/N). (Nf,2) array of data: (Nf,1) vertical, (Nf,2) lateral. |
| out.int.ur | The rail response (m/s). (Nf,2) array of data: (Nf,1) vertical, (Nf,2) lateral. |
| out.int.uw | The wheel response (m/s). (Nf,2) array of data: (Nf,1) vertical, (Nf,2) lateral. |
Whilst other variables may be included within the Matlab output file, these are for the development team’s internal use only. For further clarifications, please Contact us.