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Old 11-22-2012, 05:48 PM   #1597
lancelucas
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Quote:
Originally Posted by manitou View Post
No, what I am saying is their flow does not change as much as other injectors at different fuel pressures. I know they flow well at all pressures. What I was saying is that you can get higher flows from higher pressure with some DW injectors.
Incorrect. Bernoulli's principle. Read it learn it love it.

Quote:
Bernoulli is the guy who discovered that for the flow of an incompressible fluid through an orifice to double, the pressure must quadruple. Put another way, the change in flow is proportional to the square root of the pressure ratio. I think it's safe to say that all of us who play with fuel injectors get this, and in fact a quick Google search will bring up numerous injector flow rate calculators that are based on this exact principle.
http://www.injectordynamics.com/size14.html

Basically, your 1100's -- assuming the 1100cc rating is accurate -- can only flow at a very theoretical max of 1283cc with the stated pressure increase. 3 bar to 4 bar is a 33.3% (1/3) increase in pressure, which means a 1/6th (16.6%) increase to flow rate, or 1100 * (1 + 1/6) = 1283.33. All injectors are subject to the same principles of fluid dynamics

Because I love math -- note that the ID1000 and ID2000 flow goes up by ~16.26% and ~15.73%, respectively, when pressure is increased from 3 bar to 4 bar. The theoretical increase should be 16.6%. Not a coincidence
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Last edited by lancelucas; 11-22-2012 at 06:07 PM.
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