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Unread 11-17-2004, 10:55 AM   #55
BillA
CoolingWorks Tech Guy
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Join Date: Dec 2000
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Quote:
Originally Posted by Incoherent
(from Nexxos thread regarding PQ)

Re the P=Q^1.85 fit, I think there is a better way.

I assume you are familiar with the idea of a "k-factor", I stumbled across it recently when exploring the flow measurement problem.
Your PQ curves are not behaving, shouldn't one be able to generate a constant which, even allowing for transitions between flow regimes and boundary conditions, is relatively flat across flowrate?. I am getting this with measured data, (see attachment) it is constant enough that I would propose that every block has a "K-factor", a constant encompassing restrictivity described by the equation: K=Q/sqrt(dP) or P=(Q/K)^2, essentially the flow rate squared relationship. It's probably your curve fit that I am seeing, it is not generating a constant. If it is real, that's very interesting, there's probably a way to extract a Reynolds number curve from it.

Sorry if I am being disruptive, I have not been following this closely but I thought the K-factor thing might be relevant. It for sure is another way to generate a PQ curve from a single data point...

yes, you are correct
I am in the process of converting all Swiftech flow resistance curves to a 'K-factor'

pH or Cathar
why not write an article on flow resistance characterization ? (yes, I'm lazy)
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