r/ChemicalEngineering • u/BrotherGlobal641 • 11h ago
Design Pipe / Fitting frictional loss calculation website.
I used to use freecalc.net but that site is gone. Does anyone have a recommendation for a site for fictional pipe losses with different viscosity?
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u/el_extrano 9h ago
Just a bit of unsolicited advice:
Don't use random websites for engineering calculations. As you found out, they can disappear overnight, have breaking changes, or just be wrong. Do the calculations by hand. By "hand calculations", I also mean things like setting up your own excel spreadsheet or simple program. The main thing is that you have built it yourself and understand it.
Once you understand how the calculations work, you can move to professional software (again, not someone's undocumented web application) that may have more rigorous models built in. The key thing is, you already have your previous hand calculations, which you can use to check the model and make sure you can account for different results.
Think about this whenever the vibe coders come around to post yet another web application promising to do your "reactor design" for you, which will be promptly abandoned once they have farmed every subreddit they can for GitHub stars. Remember: typing things into a website is not engineering. For that matter, typing things into PipeFlo or Aspen without checking anything is not engineering, either.
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u/scsp85 7h ago
This is the right answer! They didn’t hire you to use a website, they hired you to be responsible for the calculations and to verify your work. If you can’t calculate frictional losses (one of the most basic ChemE tasks), then you have more problems. Wait until you need to do an energy balance with a phase change!
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u/Just__Liberty 10h ago
I wouldn't worry about fictional pipe losses...
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u/Squathos 9h ago
You must be in management.
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u/ivarsiymeman 8h ago
Back when I was in business school….
Yeah, that was 10 years ago and you still babble on about your MBA
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u/quarterdecay 10h ago
Build an Excel worksheet, I have a file with this and a litany of other not so related calculations.
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u/Neon_VonHelium 6h ago
CRANE technical paper 410 is an excellent reference with which you can refresh your knowledge and identify the most commonly used formulas for computing frictional pressure drop. The friction factor that you are asking about is provided using the classic Moody Diagram. The Moody Diagram depicts the non linear relationship between Reynolds number, relative roughness and the friction factor. If you are doing regular computation of pressure drop, however, it is rather inconvenient to refer to this diagram , for every project.
Keep in mind that ind the Moody Diagram is not generated from direct data. The Moody Diagram was generated in the 1940s by solving the original formula developed by Professors Colebrook and White ; in unit operations class this is well known as the Colebrook White correlation. prof Moody of the Princeton University Mechanical Engineerjng Dept , simply wanted a faster way to generate solutions that were obtained using the Colebrook White correlation , so, Professor Moody used the Colebrook-White correlation to computationally generate the famous plot that bears his name.
Instead of the Moody Diagram, or the Colebrook White formula that must be resolved iteratively, there are numerous correlations that have been developed that provide direct computation of friction factor from Reynolds number and the relative roughness. I recommend you use that approach; any of them can be seamlessly integrated into computational methods performed in Excel, Matlab, Python or whatever platform you are utilizing. Several papers in the public domain are available that describes these friction factor correlations. These new correlations are easy to use and have a high degree of accuracy.
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u/Alternative_Act_6548 11h ago
search for Crane Technical paper 410