The problem with Goudar-Sonnad has been solved. I had a version of Goudar-Sonnad that gave the d parameter as: d=ln(10) x Re/5.2. I believe the source was Wikipedia which now correctly lists this as: d=ln(10) x Re/5.02. With this corrected equation, I have verified that Goudar-Sonnad is the...
The Colebrook equation came first, 1937 I believe. The Moody diagram (1944) is a graphic representation of the Colebrook equation and is as accurate as you can read it; which may be a problem depending on the accuracy you seek.
Explicit forms of Colebrook are generally "curve fits" to the...
I authored the articles, http//www.cheresources.com/colebrook1.shtml with parts 2 and 3 in 2004. I'm requesting assistance in updating the explicit equations portions of that series. My problem is that I have been unable to verify the accuracy of the Goudar - Sonnad equation. I have attempted...
I disagree that "99% of real-world calcs" are in the fully turbulent region on a Moody Diagram. Low pressure steam, water, compressed air and ducted air under normal conditions fall in "Transition Zone" of Moody's original 1944 diagram or the "Rough with Re Dependence" in more current versions...
If you are an Excel user, I'd suggest you read the article I wrote for the ASHRAE Journal in Aug 2009. Google "Using Excel for Duct Calculations". That article covers ducted air but I've created spreadsheets for steam, compressed air, water, etc. All are basically constructed the same way.