Calculate theoretical static pressure

[frozenguy]

Hi folks, I have a pressure sensor working with arduino to measure depth. I want to calculate what I should see as a change in pressure if I move the tube horizontally under the surface of the water, keeping the tube opening parallel to the flow. I have calculated the dynamic pressure but need to calculate the total pressure to take a difference.
I can maybe turn the tube 90 deg into the flow and then measure that pressure?

Thank you!

 

[Sparweb]

Arduino... in "aerospace"... in water? I don't know how this all ties together.

Your question is about measurement and then to "calculate theoretical static pressure" as you put it. What you are doing may approximate static pressure, but just sticking a tube in the water flow does not work. The disturbance around the tip of the tube disturbs the flow and pressure at the same time.

In addition to this, if you want to measure total pressure with the tube turned into the flow, then you could estimate flow velocity from that. Total pressure = static pressure + dynamic pressure. But in water I do not think this is very effective, or necessary. In fact, there are several ways this could go wrong in water.

This is rather entry-level fluid/aerodynamics, so to brush up on the subject I suggest you find a textbook on the basic principles of aerodynamics or fluid dynamics such as White or Anderson.

STF

 

[rb1957]

isn't this what a pitot tube does ?

another day in paradise, or is paradise one day closer ?