[atsf3751]

I also wanted to show you what I meant about the 2 smoke balls coming out of the stack! It is very evident in this photo that I took of the MILW 261 in Open Rails!

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[midneguy]

copperpen, on 01 August 2014 - 07:09 AM, said:

In reality if the engine is stationary then the blower in most cases is on because there is a need to maintain fire temperature during station stops. There would however, be no smoke, just a light haze. It really annoys station masters to have smoke billowing around the station. Gets passengers dirty and leads to lots of form filling. The problem with using a single ace file is that it will only display one form and is only affected in MSTS by firing. Adding fuel darkens it followed by a period of lightening until more fuel is added. MSTS actually did a pretty good job in that respect. Here in OR on the other hand, we start with a very dark smoke which gradually turns white or white/grey, but never darkens again.

Smoke stack and cylinder cocks are different in visual terms, and there are also pressure relieving valves on later engines which emit a small puff of steam at the end of each stroke. Steam from these cocks and valves should only be white, not dark or grey like the stack.

Stack output is affected by a number of things, main ones are steam pressure at exit from cylinders, diameter of the exhaust and speed of the engine. In most cases at speed the exhaust is carried well clear of the engine by the escape velocity, but in engines with a large diameter exhaust it is a much softer exit and steam clings more, hence things like deflectors to divert airflow to lift the steam. Far as steam chest pressure values go it is quite possible that the two different forms of working could use similar values, but the main factor affecting how the steam/smoke behaves is the speed, vertical from the stack and horizontal from the train movement.

I might add something else to consider along with these comments, and Dave's idea of possibly using multiple smoke .ace's ... The more I've thought about this, the more I think there are two basic relationships that need to be accounted for.

From a soot (or color) perspective, there are two aspects - the darkness of the color, and also the density. These are both directly effected by the ratio of air being drawn through the firebox relative to the amount of fuel present. High fire mass relative to the air being drawn through the firebox will produce smoke from the stack which is both dense and dark - very sooty. On the other hand, a lower fire mass and higher air volume should produce a nearly clear stack exhaust - low density (more transparency) and lighter color (but not white) from less soot.

Now, overlaid on this is the relationship between the engine and the ambient air temperature. Summer weather really shouldn't produce much if any "white steam" coming from the stack, as the steam in the exhaust doesn't condense much if at all before it disperses in the atmosphere. In the winter though, there will be a white, condensed steam component to the exhaust. In times of high soot, this condensed steam will tend to be obscured by the darkness and density of the soot being emitted. in low soot fire conditions (higher air to fuel mass ratios) the white color will remain more prominent. The volume will vary of course with the volume of steam being exhausted from the cylinders.

To help visualize what I've described above I created a simple graphic.... The blue in the "summer" graphic depicts sky showing through the exhaust, while the whiter color in the right side represents opaque condensed steam in the exhaust. I regret I don't have any equations to share which would help in modeling this behavior...

[atsf3751]

I know exactly what you mean. The color of the smoke looks different in the winter VS Summer. One other thing is that smoke does not come out in little balls and its really annoying to see these tiny little balls of smoke coming out of the stack. They also get smaller and smaller the faster I go as well. Not sure if that's a bug or just the way its set up at the moment!

Brandon

[Genma Saotome]

WRT the little smoke balls, I think you will find that's easilly correctable by fiddling with relevant data value sin the .eng file. I showed some before and after images and data values in a thread called Exhaust of the Apocalypse... shows how dramatically different results you can get with different values.

IIRC one of the trials produced little black balls like you report so I'm pretty sure you'll have a reasonable chance of getting something quite a bit better.

[markus_GE]

The "smoke ball" problem also occurs in Diesel, though it seems steamers are more prone to it (that might, however, be just my impression, since on this board steam fans seem to be the majority).

Anyway, for diesels the problem is easily corrected giving the exhaust stack a slightly bigger diameter (balls won´t shoot up into the sky as high anymore, keeping them closer together and giving the plume a more continuous look) and increasing the min and max smoke rates. This applies to diesels, but probably steamer smoke parameters in the ENG file are a bit different. I´ll try to find out a little more, but I already once had little success.

Cheers, Markus

[markus_GE]

Looked a little through a steamer ENG file and did some crude experimenting:

In the effects section of the ENG, find the the StackFX section and try slightly increasing the last value given in there (0.2 to 0.3 is a good point to start with in diesels). This should reduce the height of the plume a little and thus give better continuity as the smoke balls get closer together.

Also, try fiddling with the following two lines, which are used to define the number of smoke balls released under certain conditions (the parameter names are self-explanatory, actually).

SteamSmokeUnitsPerPoundOfFuel( value )
SteamMaxSmokeUnitsReleaseRate( value )

Tweaking those three parameters I mentioned in this post you should be able to at least get rid of the "single smoke ball" effect. Will be some trial and error, but if I could do it with Diesels, you can do it with Steamers, too :sign_welcome:

Cheers, Markus

[atsf3751]

I fixed it! Just need to do this to the rest of my steam locomotives now!

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[markus_GE]

:sign_welcome: Great to hear that :sign_thanks:

Would you mind sharing your findings on steamer smoke with me, so that once I get around to it, I might include an auto-fixer into my DPU program?

Cheers, Markus

[jared2982]

Is there a way we can get the smoke/steam column to rise farther into the are before it curves back. At present the exhaust immediately moves horizontally after exiting the stack. This is not really typical of steam exhaust at slow speeds. The exhaust moves more vertically at first as it is exhausted from the cylinders with some force into the smoke box and then out the stack. The force of the exhaust sends the plume up at first then it will start to trail back.

[atsf3751]

I am actually tinkering around with it a little bit and trying to figure out how to get the smoke to rise a little more! I was also curious if there will ever be any more smoke options like water injector smoke and Dynamo smoke as well?

Thanks Brandon

Here is a shot of the 261 as it would have looked in the 1950s pulling a period freight!

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[atsf3751]

Here is one more shot of the MILW 261 with the freight! What do you guys think?

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[copperpen]

First we need to visit the steam code that covers firing. At present there is no break in the firing of the engine, the rate goes up and down, but never stops, rather like a permanently running auto stoker, and even they did not run non stop. This needs to change to more closely match MSTS and the real world.

If you observe the MSTS auto fireman and the fire mass, you will see that it goes up and down, but when the firemass reaches a certain level, shovelling stops. Then as the firemass reaches the lower point, shovelling starts again. This is much closer to real world firing than OR currently achieves and is the driver of the changing smoke/steam colour from the stack.

As OR currently does not actually model air temperature it is not possible to have clear or slightly hazy exhaust as you would see on a hot summer day with a puff of smoke as the coal hits the fire.

All we can do at the moment is aim for a more realistic exhaust behaviour.

PS, don't even mention oil firing, it is not in the code.

[captain_bazza]

The smokeFX in post #100 looks great. Would you please confirm the figures you used?

Cheers and thanks,
Bazza.

[atsf3751]

yeah the FX I had to change from .1 to .3 for the stack

Brandon

[markus_GE]

In order to lift the smoke higher, you will have to give it a higher "smoke ball rate" in the appropriate parameters of the .ENG file. I already listed them somewhere here, will take a look to find them again.

Found it, was in this exact same thread: http://www.elvastowe...post__p__157583

Cheers, Markus