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I don't use simple adhesion, but i'm sure the OR manual does state this will happen. I can't remember if this is universal, with or without tractive tables, OR parameters, etc. As before, I only see this with certain parameters. So to clear this up. Can you post that dash engine file?.
Thanks
issue with a permanent drop in tractive force
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#11
- Foreman Of Engines
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Posted 21 December 2017 - 03:13 AM
#12
- Fireman
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Posted 21 December 2017 - 04:49 AM
With the advanced model of adhesion is the same.
Tractive force is 162,6kN in zero speed. Time 12:00:54
After 15 minutes missing about 2.9kN in zero speed. Time 12:16:02. Tractive force is 159.7kN
I use for the test a default eng without traction tables and other parameters, because he must work without any difficulty. Otherwise the bug is in the OR.
dash9.zip (5.18K)
Number of downloads: 206
Tractive force is 162,6kN in zero speed. Time 12:00:54
After 15 minutes missing about 2.9kN in zero speed. Time 12:16:02. Tractive force is 159.7kN
I use for the test a default eng without traction tables and other parameters, because he must work without any difficulty. Otherwise the bug is in the OR.
dash9.zip (5.18K)
Number of downloads: 206
#13
- Foreman Of Engines
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Posted 01 January 2018 - 04:04 AM
Sorry for the late reply.
Yes, because the CTE is lower than MTE, this fall off will occur over time. I believe this is defaulted to 1800 seconds. This is in the OR manual, page 107 under '8.7 Dynamically Evolving Tractive Force'
CTE is a figure based on a certain speed. OR uses tractive effort drop based on HP and MTE where the tractive effort starts to fall at a certain speed, but has has no way to know real world CTE speeds unless tractive tables are included. In MSTS, i believe the parameter 'DieselEngineSpeedOfMaxTractiveEffort( 13mph )' was used for this very purpose.
Under the dash 9, what speed does the tractive effort start to fall from 650kN? I'm willing to bet that even setting the CTE to the MTE figure, the TE drop will be at the same speed?
For instance, under OR, the BR Class 47 diesel engine using correct HP and MTE will give a constant TE to almost real world figures but after 13 mph, the TE does not match real world figures. This is were tractive tables are used so that the RHP is constant to 75mph and the engine/generator starts to unload and again, the TE falls even more. This is where tractive tables are used for accurate simulation of trains.
Another thing is electric train heat(ETH). Although the generator output is reduced, this reduction only occurs between 13 and 75 mph on the class 47 diesel engine. Up to 95 mph, the tractive effort is the same, with or without ETH.
Thanks
Yes, because the CTE is lower than MTE, this fall off will occur over time. I believe this is defaulted to 1800 seconds. This is in the OR manual, page 107 under '8.7 Dynamically Evolving Tractive Force'
CTE is a figure based on a certain speed. OR uses tractive effort drop based on HP and MTE where the tractive effort starts to fall at a certain speed, but has has no way to know real world CTE speeds unless tractive tables are included. In MSTS, i believe the parameter 'DieselEngineSpeedOfMaxTractiveEffort( 13mph )' was used for this very purpose.
Under the dash 9, what speed does the tractive effort start to fall from 650kN? I'm willing to bet that even setting the CTE to the MTE figure, the TE drop will be at the same speed?
For instance, under OR, the BR Class 47 diesel engine using correct HP and MTE will give a constant TE to almost real world figures but after 13 mph, the TE does not match real world figures. This is were tractive tables are used so that the RHP is constant to 75mph and the engine/generator starts to unload and again, the TE falls even more. This is where tractive tables are used for accurate simulation of trains.
Another thing is electric train heat(ETH). Although the generator output is reduced, this reduction only occurs between 13 and 75 mph on the class 47 diesel engine. Up to 95 mph, the tractive effort is the same, with or without ETH.
Thanks
#14
- Fireman
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Posted 26 January 2018 - 05:43 AM
I created an bug report on launchpad: https://bugs.launchp...or/+bug/1745613