Forgive me for my ignorance. What would be the method to determine the pressure a non compressible fluid creates when forced though an orifice? Keep in mind this orifice does not have a constant diameter. I know the volume of fluid, the area squared of the orifice and the flow rate. I'm not a mathematician, any information you can provide will be helpful.
$\begingroup$
$\endgroup$
4
-
2$\begingroup$ That doesn't seem to be a matter of mathematics. (You'll need to know at least the viscosity of the fluid, too). $\endgroup$– hmakholm left over MonicaOct 30 '14 at 12:49
-
$\begingroup$ Its blood. forty over one hundred units of millipoise. $\endgroup$– EricOct 30 '14 at 13:11
-
$\begingroup$ You say you know the area of the orifice, but it does not have constant diameter. That's confusing. $\endgroup$– Mike DunlaveyOct 30 '14 at 13:52
-
$\begingroup$ Related question by someone also called Eric: physics.stackexchange.com/q/127954/2451 $\endgroup$– Qmechanic ♦Feb 5 '15 at 16:14
Add a comment
|
$\begingroup$
$\endgroup$
According to this doc flow rate is area times velocity times a correction factor $$Q = AVK$$ where $K$ depends on the orifice geometry, and for blood through a heart valve I suspect it is as large as possible, $1.55$. ($K$ is basically the ratio between the area of the actual flow and the measured area of the orifice - they are not the same.)
Pressure is related to velocity by Bernoulli's equation. My favorite explanation is this where pressure essentially boils down to $$1/2 \rho V^2$$ where $\rho$ is density (about 1 for blood). Then all you gotta do is get the units right.
BTW there's a calculator here.
answered Oct 30 '14 at 14:25