- Sun Jan 31, 2016 5:10 pm
#187740
Hello!
New to the forum so go easy.
I tried posting this to a reddit AskPhysics forum and just ended up getting some low effort responses, so I wanted to share my thoughts with some other people that might have some more valuable feedback
What i'm trying to do is measure the velocity of air coming out of a vent after its passed through a series of filters. Originally I had planned on hooking up this item:
https://moderndevice.com/product/wind-sensor-rev-p/
Which is a thermal anemometer. However, when I hooked it up via my redboard ( I used a regulated 12v power supply), the data I was getting back from it was far too noisy to be useful.
So I was thinking more on this issue today and I drew up this sketch:
Which led me to here:
Prandtl tube
A site from NASA outlining how a Prandtl tube works.
The basic idea here is that a Prandtl tube takes two pressure measurements, one in the direction of flow and one not, and converts that to air speed.
So i've already gone ahead and sent the cart before the horse and bought two barametric pressure sensors that I can hook up to a redboard, but my conundrum here is really about physics.
My thought is that one pressure sensor can be mounted inside the box, and one outside, and I can use the two measurements in terms for solving the bernoulli equation. I'm stuck however, on if the sensor that is placed inside the box needs to be facing the flow of air. My thought is that it shouldn't matter; the static pressure of the air in the whole chamber should be the same until it leaves the chamber.
Thoughts? Considerations?
New to the forum so go easy.
I tried posting this to a reddit AskPhysics forum and just ended up getting some low effort responses, so I wanted to share my thoughts with some other people that might have some more valuable feedback
What i'm trying to do is measure the velocity of air coming out of a vent after its passed through a series of filters. Originally I had planned on hooking up this item:
https://moderndevice.com/product/wind-sensor-rev-p/
Which is a thermal anemometer. However, when I hooked it up via my redboard ( I used a regulated 12v power supply), the data I was getting back from it was far too noisy to be useful.
So I was thinking more on this issue today and I drew up this sketch:
Which led me to here:
Prandtl tube
A site from NASA outlining how a Prandtl tube works.
The basic idea here is that a Prandtl tube takes two pressure measurements, one in the direction of flow and one not, and converts that to air speed.
So i've already gone ahead and sent the cart before the horse and bought two barametric pressure sensors that I can hook up to a redboard, but my conundrum here is really about physics.
My thought is that one pressure sensor can be mounted inside the box, and one outside, and I can use the two measurements in terms for solving the bernoulli equation. I'm stuck however, on if the sensor that is placed inside the box needs to be facing the flow of air. My thought is that it shouldn't matter; the static pressure of the air in the whole chamber should be the same until it leaves the chamber.
Thoughts? Considerations?