[charland]

Hi All,

I've been testing a Boson and Maine version of Gaeten Belanger's BL-2 Rich Franzosa made and am having a strange exhaust issue. The eng file shows two exhaust setting just back of the center middle of the engine at 4.7m, or 15.4 feet. When OR shows is a single large exhaust coming from the center of the engine as seen in this shot:

http://i479.photobucket.com/albums/rr160/paul_charland/142_zpsbfdd9c50.jpg

I ran this by Rick this morning and he's not sure what's causing it as the numbers in the engine file should work. When you are running the engine it's clear there is not exhaust from the front stack and the entire carbody is engulfed in smoke originating four or five feet from the railhead. This is not happening with other power that I've run in OR.

Paul :-)

[James Ross]

My guess would be that the hole (7th and final value in the *FX data IIRC) is much larger than it should be for the volume of emissions (controlled by other parameters in the .eng). The emissions come out at the physically-correct velocity for volume-rate/area so if the hole is huge, the velocity is very low, which means the particles don't move very far from the locomotive - instead, as they expand, they engulf the locomotive.

[charland]

Hi James,

Here is the entry for the exhaust, you think the 0.7s should be smaller? If you look at the shot the exhaust appears to be originating at 4.7 feet and not 4.7 meters (OK, metres). I'm guessing reducing the 0.7 will only reduce the maximum diameter of the exhaust and not the location.

--------------------------

Effects (
DieselSpecialEffects (
Comment (
the format of these little blocks is as follow:

offset.x offset.y offset.z
normal.x normal.y normal.z
width in metres

defining the offset from the shape pivot point
where steam / smoke should appear, the direction
it should go and the width of the nozzle
)
Exhaust1 (
0 4.7 -0.32
0 1 0
0.7
)
Exhaust2 (
0 4.7 -2.62
0 1 0
0.7
)
)
)

----------------------------------

I'll tinker with it and see what happens, thanks.

Paul :-)

[markus_GE]

Try reducing the diameter of the exhaust first. As James explained, slow exhaust will expand more quickly, therefore covering quite a bit of the loco and making it hard to make out where it actually originates.

0.7 is quite a large exhaust pipe opening. My standard value to start experimenting from is 0.25, so maybe try inserting that in place of 0.7.

Cheers, Markus

[charland]

Hi Markus,

Reduced the .7s to a .3s. Still coming out of the center middle of the carbody in OR but working fine in MSTS. Not sure what to make of this, I'll open one up in another route in OR and see what happens.

Paul :-)

[charland]

OK, I reduced the last entry for each of the exhausts from 0.7 to 0.3, then again to 0.1 and that solved the issue:

http://i479.photobucket.com/albums/rr160/paul_charland/151_zps183f9671.jpg

This comes with a bit of a warning though... in the mid-1980s the Vermont EPA forced the Central Vermont to remove their collection of RS-11s out of the State for looking like this! Is there a way to make the exhaust look less dense and maybe a little lighter grey?

Paul :-)

[markus_GE]

Glad it finally worked.

In order to reduce the density of the smoke, the only option is to reduce the DieselSmokeEffectInitialSmokeRate and ...MaxSmokeRate parameters. But be careful not to go too low, as you might get puffy smoke then.

Cheers, Markus

[charland]

OK, thanks Markus, I'll bring them both down a little at a time and see how it goes.

Paul :-)

[James Ross]

charland, on 23 June 2014 - 07:34 AM, said:

Here is the entry for the exhaust, you think the 0.7s should be smaller? If you look at the shot the exhaust appears to be originating at 4.7 feet and not 4.7 meters (OK, metres). I'm guessing reducing the 0.7 will only reduce the maximum diameter of the exhaust and not the location.

0.7 is huge! This value is a length - the diameter of the hole - so it is in meters. 0.7m means you've got a hole 70cm across for the smoke to come out of; it is no wonder it was coming out so slowly. :sign_thanks:

It's occurred to me that we have no way to cope with fan-assisted smoke exhaust, or anything of that nature, so you may have to make the hole smaller than prototypical to compensate if the locomotive is still looking strange with the real dimensions.

[charland]

Hi James,

I changed the diameter from .7s to .1s. I also changed the four entries for the exhaust to:

DieselSmokeEffectInitialMagnitude ( 1 )
DieselSmokeEffectMaxMagnitude ( 2.5 )
DieselSmokeEffectInitialSmokeRate ( 1 )
DieselSmokeEffectMaxSmokeRate ( 3.5 )

Idle:

http://i479.photobucket.com/albums/rr160/paul_charland/152_zps00e1896c.jpg

60% at about 15 mph:

http://i479.photobucket.com/albums/rr160/paul_charland/153_zps531dc613.jpg

100% at about 25 mph:

http://i479.photobucket.com/albums/rr160/paul_charland/154_zps7e3dd403.jpg

\Appears to have worked and also worked in MSTS.

Paul :-)