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Diesel Locomotive Performance Rate Topic: -----

#181 User is offline   Laci1959 

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Posted 08 May 2020 - 11:00 PM

Good afternoon. Sorry, if it makes no sense at times, Google translates.
Perhaps the previously introduced ORTSTractionCharacteristics should be taken forward. That's a very good thing. The curves can be completely customized in all stages. Unfortunately, there are machines for which only one curve is given, but there are many stages. I can't process this yet, or OR won't do it. I processed the curve for one stage and copied the column to the other stages. The result was disappointing.
Thank you so much for commenting. I learn a lot here.

This post has been edited by Laci1959: 08 May 2020 - 11:00 PM


#182 User is offline   ErickC 

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Posted 30 May 2020 - 07:56 AM

I've just created a curve for the EMD GP9 based off formulae included in Management of Train Operations and Train Handling. I used the custom power curve in my diesel power table to determine the available power in each notch, then used the following formula for a constant-power locomotive to create the TE values:

( HP * 308 ) / (SPEED IN MPH)

The end result has been close to what acquaintances who work in the industry have described to me in terms of running real GP9 locomotives - I was told, for example, that if you try to apply more than notch 2 or 3 at a standstill, the wheels will slip. Sure enough, the locomotive seems to want to slip at the right times and in the right throttle settings, and it wants to accelerate just the way real GP9s do. This is not the problem. The manual says that the ORTSMaxTractiveForceCurves table plots power vs speed at different throttle settings, however, it appears that the sim is actually using the percentage of engine RPM and not throttle position. This is problematic because, as in the real world, I have programmed my locomotives' engine RPM to drop slightly between idle and Run 1 as the engine loads. A drop of 5 or 10 RPM is pretty typical for most early EMD locomotives. This means that, in OR, the locomotive has some pull in idle, and none in Run 1. Is there any way that the workings of this table can be modified so that the TE curves depend on the actual throttle position, not engine RPM?

#183 User is offline   darwins 

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Posted 30 May 2020 - 10:20 AM

Hi Erick

Have you looked at the thread on engine rpm and power output that I posted recently?

I had a similar problem with an old British diesel with a two-stroke engine.

My understanding is that at the moment OR can not handle a drop in rpm. This is because of the nature of tables used for the computer to look up values - it expects values to be in increasing order. There is a problem with values that change direction - increase and decrease and increase again.

What will work in your ORTSMaxTractiveForceCurves is to have a minimal increase between OFF and Notch 1 - just 1 rpm is sufficient. To your ears the engine is still idling but you are now applying power to the wheels. I ended up with a diesel engine like this:

ORTSDieselEngines ( 1
Diesel(an
IdleRPM ( 375 )
MaxRPM ( 625 )
StartingRPM ( 350 )
StartingConfirmRPM ( 380 )
ChangeUpRPMpS ( 50 )
ChangeDownRPMpS ( 40 )
RateOfChangeUpRPMpSS ( 10 )
RateOfChangeDownRPMpSS ( 10 )
MaximalPower ( 1200hp )
IdleExhaust ( 20 )
MaxExhaust ( 40 )
ExhaustDynamics ( 5 )
ExhaustDynamicsDown ( 0.5 )
ExhaustColor ( 113C5050 )
ExhaustTransientColor ( 11283232 )
DieselPowerTab (
0 0
375 7457
376 90230
377 181205
378 257266
385 348242
418 439217
450 530193
475 621168
525 712143
585 803119
625 894840
)
DieselConsumptionTab (
0 0
375 32
376 48
377 64
378 95
385 123
418 171
450 207
475 243
525 277
585 312
625 335
)
ThrottleRPMTab (
0 375
10 376
20 377
30 378
40 385
50 418
60 450
70 475
80 525
90 585
100 625
)
DieselTorqueTab (
0 0
375 190
376 2247
377 4502
378 6375
385 8607
418 10024
450 11240
475 12476
525 12941
585 13097
625 13659
)
MinOilPressure ( 40 )
MaxOilPressure ( 90 )
MaxTemperature ( 120 )
Cooling ( 3 )
TempTimeConstant ( 720 )
OptTemperature ( 90 )
IdleTemperature ( 70 )
)
)



and then put the ORTS tractive force curves to match the throttle notches:
ORTSMaxTractiveForceCurves (
0.00 (
0.0 0
35.6 0
)
0.10 (
0.0 44482
0.8 29655
1.5 14827
2.3 9885
3.0 7414
3.8 5931
4.5 4942
5.3 4236
6.0 3707
8.2 2742
10.3 2176
12.4 1803
14.5 0
35.6 0
)
0.20 (
0.0 80068
0.8 63248
1.5 39756
2.3 31091
3.0 26133
3.8 22658
4.5 19924
5.3 17614
6.0 15569
8.2 11517
10.3 9138
12.4 7574
14.5 6467
16.7 1388
18.8 0
35.6 0
)
0.30 (
0.0 115654
0.8 115654
1.5 73241
2.3 56360
3.0 46892
3.8 40389
4.5 35370
5.3 31197
6.0 27554
8.2 20383
10.3 16173
12.4 13405
14.5 11446
16.7 5732
18.8 1311
20.9 0
35.6 0
)
0.40 (
0.0 115654
0.8 115654
1.5 94216
2.3 75836
3.0 64870
3.8 56869
4.5 50351
5.3 44681
6.0 39540
8.2 29249
10.3 23208
12.4 19236
14.5 16424
16.7 14330
18.8 8936
20.9 4639
23.0 1134
25.1 0
35.6 0
)
0.50 (
0.0 128998
0.8 128998
1.5 114974
2.3 95112
3.0 82663
3.8 73179
4.5 65179
5.3 58025
6.0 51402
8.2 38023
10.3 30171
12.4 25006
14.5 21351
16.7 18629
18.8 16522
20.9 11454
23.0 7320
25.1 3885
27.3 984
29.4 0
35.6 0
)
0.60 (
0.0 128998
0.8 128998
1.5 128998
2.3 114588
3.0 100641
3.8 89659
4.5 80161
5.3 71509
6.0 63387
8.2 46889
10.3 37206
12.4 30837
14.5 26330
16.7 22973
18.8 20374
20.9 18304
23.0 13539
25.1 9579
27.3 6235
29.4 3379
31.4 941
33.5 0
35.6 0
)
0.70 (
0.0 186825
0.8 186825
1.5 156923
2.3 134064
3.0 118619
3.8 106140
4.5 95143
5.3 84993
6.0 75373
8.2 55755
10.3 44240
12.4 36668
14.5 31309
16.7 27316
18.8 24227
20.9 20556
23.0 16465
25.1 11539
27.3 7912
29.4 5401
31.4 3268
33.5 1592
35.6 443
)
0.80 (
0.0 186825
0.8 186825
1.5 177898
2.3 153541
3.0 136597
3.8 122620
4.5 110124
5.3 98476
6.0 87358
8.2 64621
10.3 51275
12.4 42499
14.5 36287
16.7 31660
18.8 28079
20.9 23825
23.0 19083
25.1 13712
27.3 9739
29.4 7013
31.4 4637
33.5 2709
35.6 1397
)
0.90 (
0.0 222411
0.8 222411
1.5 198873
2.3 173017
3.0 154576
3.8 139100
4.5 125106
5.3 111960
6.0 99344
8.2 73487
10.3 58310
12.4 48329
14.5 41266
16.7 36004
18.8 31932
20.9 27296
23.0 21863
25.1 18149
27.3 15259
29.4 12041
31.4 9036
33.5 6405
35.6 4648
)
1.00 (
0.0 222411
0.8 222411
1.5 222411
2.3 222411
3.0 222411
3.8 177929
4.5 148274
5.3 127092
6.0 111206
8.2 82262
10.3 65273
12.4 54100
14.5 46193
16.7 40303
18.8 35745
20.9 30329
23.0 24292
25.1 20165
27.3 16954
29.4 13379
31.4 10040
33.5 7117
35.6 5165
)
)







#184 User is offline   waivethefive 

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Posted 10 June 2020 - 05:39 AM

I came across this EMD brochure which shows all the components used in EMD models up to the SD60. All of them list the generator/alternator used and their KW outputs and amperage.

https://www.thediese...volution%20.pdf

Not really sure if this helps or confirms any of the physics work, but I will just throw it out there.

#185 User is offline   edwardk 

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Posted 23 October 2020 - 03:01 PM

Peter,

From what I am noticing, the combination MaxPower(3100.4kW)(4,157hp) and ORTSDieselEngineMaxPower(3281kW)(4400hp) may have issues. I am noticing that the first Power column is falling short 100hp or so when running at full throttle. I did try using Watts and the result is the same. I was leaning towards a conversion issue with the HUD, but I am now wondering if this is internal. The basic physics from what I have read should only need the above 2 items. Is this still the case or am I missing another ORTS entry? As it is, I would have to increase the MaxPower() value to get the expected results.

Edit: The above kW values are examples and the issue still happens no matter what I use.

#186 User is offline   edwardk 

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Posted 23 October 2020 - 03:34 PM

I am beginning to think the issue is with MaxPower(). I experimented by taking out the ORTSDieselEngineMaxPower() line and yes the hp is higher, but the first power column is still under the max 4400hp. According to the code, if ORTSDieselEngineMaxPower() is not present, then this value is assigned internally by MaxPower(). I should be seeing 4400hp in both power columns when at full throttle.

#187 User is offline   steamer_ctn 

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Posted 23 October 2020 - 04:50 PM

View Postedwardk, on 23 October 2020 - 03:01 PM, said:

From what I am noticing, the combination MaxPower(3100.4kW)(4,157hp) and ORTSDieselEngineMaxPower(3281kW)(4400hp) may have issues. I am noticing that the first Power column is falling short 100hp or so when running at full throttle. I did try using Watts and the result is the same. I was leaning towards a conversion issue with the HUD, but I am now wondering if this is internal. The basic physics from what I have read should only need the above 2 items. Is this still the case or am I missing another ORTS entry? As it is, I would have to increase the MaxPower() value to get the expected results.

The value shown in the HuD on the LHS is the required power to overcome the current load resistance (hence why it is always changing), not the available power that the locomotive can produce. This power is capped at the value configured in the MaxPower parameter.

For a train to move, the value in the HuD should always be slightly less then the MaxPower value, otherwise the "retarding" force and the "pulling" force would be balanced, and the train would not move.

To correctly test whether a locomotive is correctly setup we need a "real life" scenario which gives us the following three test points - tonnage rating, ruling gradient, and speed of travel expected. The train should be able to meet these criteria.

Have a look at this stock.

If you still think that there is an issue, then use the above stock to highlight your concerns.

Thanks

#188 User is offline   edwardk 

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Posted 23 October 2020 - 06:22 PM

View Poststeamer_ctn, on 23 October 2020 - 04:50 PM, said:

The value shown in the HuD on the LHS is the required power to overcome the current load resistance (hence why it is always changing), not the available power that the locomotive can produce. This power is capped at the value configured in the MaxPower parameter.

For a train to move, the value in the HuD should always be slightly less then the MaxPower value, otherwise the "retarding" force and the "pulling" force would be balanced, and the train would not move.

To correctly test whether a locomotive is correctly setup we need a "real life" scenario which gives us the following three test points - tonnage rating, ruling gradient, and speed of travel expected. The train should be able to meet these criteria.

Have a look at this stock.

If you still think that there is an issue, then use the above stock to highlight your concerns.

Thanks


I guess this is the reason for the reduced MaxPower() performance? Do actual locomotives follow this? Is it possible this should be ignored if ORTSDieselEngineMaxPower() is used since MaxPower() is now representing the net hp to rails?
// Maximum rail power is reduced by apparent throttle factor and the number of engines running (power ratio)
                    float maxPowerW = LocomotiveMaxRailOutputPowerW * DieselEngineFractionPower * LocomotiveApparentThrottleSetting;


#189 User is offline   edwardk 

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Posted 23 October 2020 - 07:01 PM

I am only questioning why MaxPower() is unable to reach max power when used as net hp to rail and also when it is used by itself as in MSTS. I have not progressed to tables so I am sure the operation will be different. There is no question about the setup since in my case I am only using the Basic Physics which only requires 2 lines.

#190 User is offline   Lamplighter 

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Posted 22 November 2020 - 11:13 PM

Hi all!
With the stable version OR 1.3.1, power failures occur (the locomotive cannot increase power) when the locomotive is stopped and started or idling.
At first I thought I had a bug in the ORTSDieselEngines engine section, but I didn't find any.
When I replaced the ORTSTractionCharacteristics parameter with the ORTSMaxTractiveForceCurves parameter with the same values, everything was fine.
For the OR unstable and MG versions, there are no problems with the ORTSTractionCharacteristics parameter. Everything works normally.
The ORTSTractionCharacteristics parameter is given in Chapters 8.2.2 and 8.2.3 of the NE manual for diesel-electric and diesel-hydraulic vehicles.
So I don't understand why it doesn't work in the stable version 1.3.1.

To make sure I write correctly:

ORTSTractionCharacteristics ( rows columns
throttle ( notch0 notch1 ... notchX )
table (
speed0 force0 force1 ... forceX
speed1 force0 force1 ... forceX

...

speedX force0 force1 ... forceX
)
)


speed in km/h
force in kN


ORTSMaxTractiveForceCurves (
notch1 ( speed1 force1
speed2 force2
speed3 force3
… …
)
notch2 ( speed1 force1
speed2 force2
… …
)
)


speed in m/s
force in N

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