[Hobo]

Has there been any development on engine file structure for the oil burners ? They have oil flow adjustments , have burn pans instead of grates and some use different types of oil - different btu and heater requirements . also stack smoke colour and volume varies much more often with the oil burners , as adjusted .

Do we still have to " Fudge " coal and wood engine files to get our reasonable performance results ?

Just Askin' !

Hobo

[darwins]

No progress to date as far as I know.

One of the issues was that "grate area" is essential in the present fire model for the steam loco. It is not really a parameter for oil burning though and the texts say that firebox volume is the more important variable. Not sure how we can deal with that.

I have been thinking a little about fire. Probably one of the most difficult things to model in a simulation. It is also a factor in smoke colour when thinking about primary and secondary air and complete or incomplete combustion.

Coke Fire (as on early steamers) is less complicated - the fuel is almost all solid carbon - so burns at a steady rate depending on air supply. Insufficient air gives carbon monoxide and reduces heat output.

Oil Fire is also one kind of fire - volatile hydrocarbons which burn rapidly - too little air gives carbon and carbon monoxide.

Coal (and wood) are more complex - being a mixture of volatiles that burn rapidly when released and carbon which burns more slowly. So the need to consider both primary and secondary air to work out heat output and smoke colour.

[Traindude]

darwins, on 25 September 2022 - 01:07 AM, said:

One of the issues was that "grate area" is essential in the present fire model for the steam loco. It is not really a parameter for oil burning though and the texts say that firebox volume is the more important variable. Not sure how we can deal with that.

IIRC, many locomotive builders use "grate area" on oil burners as an equivalent measurement of the firebox floor area, even though there is no physical grate inside the firebox. Here are some examples for the famous Southern Pacific "Golden State" 4-8-4 Locomotives. As one can see, theoretically firebox volume can be calculated if the equivalent "grate" area and the firebox areas (crown, flue, side, door and throat sheets, as well as any syphons, circulators nor arch tubes) are known.

For example, the GS-2 class has an equivalent grate area of 90.2 square feet, and a firebox area of 356 square feet. However, my attempts to Google the correct formula have proven unsuccessful. Well, at least I tried!

Here's a drawing of the GS-2 boiler in case someone else wants to take a stab at calculating the firebox volume!