Quote:
Originally posted by Since87
LOL, was wondering.
1)I've been playing around with numbers towards adding a 'barb ID factor' to the spreadsheet. I'm not familiar with the correct equations for this stuff. (Involves someone named Darcy right?)
I've just been fiddling around in Excel trying to match Bill's 2 gpm data from the chart here. The equation:
dP = .00156 * ID^-5
gives the match shown here:
I like my equation.  It's simple and hits half the points dead on, unfortunately, I have no idea whether there is any justification for it in fluid dynamics.
2) Les, would you mind detailing how you applied the correction for Big Momma's barbs? Or, rework the spreadsheet to take a barb ID as user input?
3) Do you think a 'barb factor' should replace the 'overhead factor' completely or only partially?
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1) Think I prefer (From visual inspection of same Billa data)
From distant memory think fourth power has some justification in fluid dynamics( have to check)
2) Again from visual inspection of same Billa data.
Difference at 2gpm between 2x( 0.488"ID) and 2x(0.3" ID) = 1.3 psi = 8.96KPa.
Did rough convert to ~ 0.896m(H20) should be 0.9149m(H2O).
Simply used the 0.015972. Have been using this for the "Cathar Big Arse" v "Big Momma" and has been giving results.
Whether correct is another question - eg using 2 Barb correction (and is Billa data single Barb - think it is but not sure).
3) Ugh and dunno. I am possibly the last person to ask for conciseness/simplification.Think prob wait for more data with which to play(torture).
EDIT1: Deleted inane comment.
EDIT2: Corrected explanation of arrival at. 0.015972 "fudge factor". Used 0.3"(not 0.25" or 0.25- 0.3") as ID of 3/8" Barb. Excuse is it is a long time since did it.