A straight forward method to solve Colebrook Equation in Excel or OpenOffice is presented in the book:

The following papers appeared in web describes various alternatives of Colebrook Equation and methods existing by Thomas G. Lester, P.E., Bergmann Associates

The author sugges VBA and UDFs as the methods by which Colebrook Equation be solved!

http://www.cheresources.com/colebrook1.shtml

http://www.cheresources.com/colebrook2.shtml

http://www.cheresources.com/colebrook3.shtml

As author of the referenced articles, http://http//www.cheresources.com/colebrook1.shtml, I'm requesting assistance in updating 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 to enter the equations in an Excel spreadsheet but the results are not to the stated accuracy.

ReplyDeleteSpecifically, I have tried to test Goudar against Serghide at the point of maximum error in Serghide, which is at Rel Roughness of 0 and Reynolds Number of 171,000. As I have entered the formulas, I get a result from Goudar of f = .0162416. An iterative solution would yield f = .0161281. Back substitution of these results into the original Colebrook equation would suggest that the iterative solution is more accurate.

I'd appreciate any comments or assistance.