Flow through a hole, very high dP 1

[subsearobot]

I am looking at the feasibility of using a small horsepower pump (~5 gpm, ~2000 psi) to drive water out of N number of small holes along the length of a "large" diameter pipe. I want to maintain pressure, so the sum of all flows thru the holes must be less than the maximum that the pump can output.

Does Bernoulli apply to high velocity situations like this? I imagine that there will be heat generated etc. I can't quite remember, but I do not believe that incompressible fluids experiences "choked flow", but can't find a reference saying so. Am i remembering correctly?

My main question is: how do I determine flow thru a small orfice (say 1/16" diameter, thru a 1/8" wall) with a pressure differential of ~2000psi?

thanks!

 

[cpretty]

This website has some of the better references on orifice flow.

http://www.okcc.com/catsub_precision.htm

The technical considerations link is good to explain how it works, and the lookup tables are great for quick comparisons.

I assume once you have flowrate, you can then calculate the power requirements for the pump, or similarly ability to hold pressure, or allowale number of holes.

Cheers,
Craig

Craig Pretty
Tru-Design Plastics

 

[MortenA]

Dont worry - the sum of all flow will always be just wthat the pump can manage - although it may not be what you wish/require.

Best regards

Morten

 

[subsearobot]

thanks Craig,
That page is exactly what I was looking for.

-Seton