digital steam engine indicator

A special section just for steam engines and boilers, as without these you may as well fit a sail.
Steam Captain
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Re: digital steam engine indicator

Post by Steam Captain » Mon Nov 23, 2020 10:32 pm

Thank you. I also tried to structure the code itself to make it as readable as possible to make modding for others easier.

Also, as I now have uploaded the manual, I got a question myself: I used the standard imperial-unit formula PLAN/33000 to calculate the indicated HP. I am now wondering if there's already an efficiency-factor hidden in the 33000. If so, the efficiency factor would need to be removed to get the real indicated HP. If someone can answer that, I could change it asap.
My steam engine indicator: https://gofile.io/d/IImyiP
Mike Rometer
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Re: digital steam engine indicator

Post by Mike Rometer » Mon Nov 23, 2020 10:42 pm

I was taught PLAN/33000 for HP some 50 odd years ago. I've never heard it suggested that it was "interfered" with. Does anybody know different? You do need to make sure you allow for double acting cylinders. Wiki says that 33,000 is rounded up from 32,572.
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Re: digital steam engine indicator

Post by Steam Captain » Mon Nov 23, 2020 10:50 pm

Yes, that's all settled. The indicator has the options to choose between single- and double action and all the other important stuff as far as I am aware of uptil right now. Just this factor bugs me, because whenever I searched for an imperial formula, it spot out the PLAN/33000 formula. But never did it explain what the factor 1/33000 is made up of. I want to give the user the possibility to calculate the efficiency of the engine. That's only possible if my power calculations aren't influenced by a rule-of-thumb efficiency factor.
My steam engine indicator: https://gofile.io/d/IImyiP
Mike Rometer
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Re: digital steam engine indicator

Post by Mike Rometer » Mon Nov 23, 2020 11:10 pm

I think you're safe. It's all about the horse, and they do come in different sizes, even Watt got caught by that and he reputedly devised the figure. I think really it's about having a standard.
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Re: digital steam engine indicator

Post by Steam Captain » Tue Nov 24, 2020 1:41 pm

Since I was wondering if the download link gets lost while this thread is going on, I simply put the download link into my signature. I don't need to dig up the link all the time that way. I think I'll still use this threat though to collect any input, announce new versions etc.
My steam engine indicator: https://gofile.io/d/IImyiP
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fredrosse
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Re: digital steam engine indicator

Post by fredrosse » Tue Nov 24, 2020 4:41 pm

The value of 33,000 ft-LBf per minute was standardized by Mr. Watt nearly 250 years ago, and the calculation given in Wikipedia neglects to mention that the precision of measurements leading to the calculation giving the 32,572 value was necessarily so coarse that maybe only 2 significant figures would be meaningful, so 33,000 is the proper number to use.

Boulton and Watt settled on the standard of 33,000 ft-LBf/min long before the dawn of the 19th century, and the 32,572 figure is perhaps an intellectual curiosity, but nothing more.
Last edited by fredrosse on Tue Dec 01, 2020 10:43 pm, edited 1 time in total.
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Re: digital steam engine indicator

Post by Steam Captain » Wed Nov 25, 2020 2:44 pm

Thank you the both of you for the explanation. I noticed I asked in a little clumsy way, which might have been a little misleading. So, does that mean "PLAN/33000" IS the proper calculation for the pressure-volume work without efficiency factors?
My steam engine indicator: https://gofile.io/d/IImyiP
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Re: digital steam engine indicator

Post by Mike Rometer » Wed Nov 25, 2020 3:51 pm

Without a doubt.
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Re: digital steam engine indicator

Post by Steam Captain » Thu Nov 26, 2020 1:04 pm

Ahhhhh, now I get it. thank you. Then, everything is fine with the calcs in the indicator.
My steam engine indicator: https://gofile.io/d/IImyiP
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Re: digital steam engine indicator

Post by Steam Captain » Fri Nov 27, 2020 1:22 am

I noticed it is not easy to simply copy the code out of the document, since it wouldn't copy the format and the page numbers and headers would be in the middle of the code. So, I am uploading the code separately. The Manual will be changed accordingly.
My steam engine indicator: https://gofile.io/d/IImyiP
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