areaAve(Pressure) with back flow
 

Hey,

i have a problem regarding the right pressure measurement of areaAve.

I have a pipeflow arrangement like shown in attachement 1. The diameter suddenly decreases.

Now i am trying to get the pressure distribution along the pipe. I create a plane and move it along the pipe, taking the area averaged pressure at every step. The result is shown in attachement 2.

How can i get rid of this downswing? My guess is, that it is probably because there is a backflow around the core flow like shown in attachement 1.

any suggestions are appreciated.

This is real - the flow is accelerating in the vena contractor and has a locally reduced pressure.

If you want to get rid of this then use a rounded pipe entry. Make sure the radius is large enough that it does not separate. Or even better use a more optimal shape like an elliptical profile.

Thank you for your answer.

In fact wasn't looking for a solution to prevent the separation, but for a way to get the "right" pressure distribution. I obviously did not make it clear enough.

But thank you anyway, because it reminded me of a person named Daniel Bernoulli, who said that there is not only the static pressure, which i get from areaAve(Pressure), but also the dynamic pressure. :)

massFLowAve(Total Pressure)?

Are you trying to compare this to something?