Why does the Hazen-Williams model give infinite flow rates at Reynolds 10^5?

[Clausius2]

Is there some reason for Hazen-Williams friction model to failure in a hydraulic circuit?.

I have simulated an hydraulic system in a commercial code, and this model is the unique which gives stupid results like infinite volumetric rates. The Reynolds is about 10^5.

 

[FredGarvin]

My reference as well as the website here (http://www.piping-toolbox.com/6_797.html) show that you are right on the edge of $$R_e$$ for using Hazen-Williams. Also, are you possibly outside the realm of this:

Note that the Hazen-Williams formula is empirical and lacks physical basis. Be aware that the roughness constants are based on "normal" condition with approximately 1 m/s (3 ft/sec).

I guess after we discount those two notions, the model will have to go under the microscope. Is there any way to compare your model to Darcy?

 

[Clausius2]

My reference as well as the website here (http://www.piping-toolbox.com/6_797.html) show that you are right on the edge of $$R_e$$ for using Hazen-Williams. Also, are you possibly outside the realm of this:


I guess after we discount those two notions, the model will have to go under the microscope. Is there any way to compare your model to Darcy?

It doesn't help too much, but thanks anyway .

The problem is I have to switch between friction models when calculating an hydraulic installation, but this model is the unique which spends the longer computational time and gives unbelievable results. I was searching for same sort of conditions in which this formula is applicable, but I haven't found nothing interesting for justifying this fact.