How faucet aerators work

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1. Jun 22, 2015

fatehah

1. The problem statement, all variables and given/known data
Trying to figure out how faucet aerators work–currently designing an experiment. I'm going to use plastic mesh with different sizes of holes for the screen. The smaller the total area of flow the more restricted the flow of water, yeah? Because more air is added to the flow and there's less space for water. But then you've also got an area of higher pressure (than normal water pressure) forming behind the faucet aerator because of the water that's being held back and so the pressure difference increases the velocity of the water.

What I want to do is measure the final force of the water and compare it to the flow (kgs^-1) to see the if you can save a lot of water without feeling the lack, which I get sometimes with low-flow showerheads. Is the final velocity of the water a good measure of the 'perceived force' of the water? And how do I measure the velocity of the water?

Or maybe I have things backwards because I don't see how you can save a decent amount of water if the aerator's limiting the flow but it's also coming out faster.

2. Relevant equations
Theory of turbulent flow through a constriction?
Q=k√P,
where Q = flow rate in cm3s-1,
∆P = Pressure difference (kg/cm2) in the faucet aerator
and k is a form of discharge coefficient

3. The attempt at a solution
I thought maybe putting a set of scales beneath the water at the set distance could measure the (instantaneous) force of the flow/weight of the water? Then I wouldn't need to use velocity as a measure of the perceived force of the flow.

This experiment will be attempted at a tap.

I'd love any and all help anyone would be able to give. Thank you!

Last edited: Jun 22, 2015
2. Jun 28, 2015