Pressure Tap Location: Reasoning Needed

[sycorax]

I need to measure the pressure drop across a core( let's say a restriction). Air is flowing ( around 15 g/sec) in a 4"ID tube which is very long( irrelevant). Now there is a core ( or let's call it some restriction) in the pipe which is 10" long and around 3.92" wide which fills in the 4" tube. Now where do I place the pressure taps? Do i place right near the core/restriction around 1" in front of it and 1" behind it or do i place quite some distance from it , like 10" in front of it and 10" behind it.

Any logical reason behind selecting where to put the pressure taps.

Appreciate your replies. Thanks.

 

[MrMatt2532]

Is this core/restriction porous?

Also, what is your goal? To find the pressure drop caused by the core/restriction?

 

[Vadar2012]

It's hard to imagine what the hell is going on. Like Matt said, where you put them depends on what you're trying to find. Are you after the pressure difference just around the restriction or at the front and end of the pipe? You usually don't want to place taps in the disturbed flow, but this might be what you'r after. We don't know.