Flow Estimating

[sewerratt]

My maintenance people are asking for a way to estimate the amount of water they are using while slow flushing hydrants to clear up red water complaints. The hydrant will run at a half-barrel for several hours until the water clears. This isnt hard flushing where we'd use a pitot to estimate flow. This is for a rough estimate to turn in for accounting purposes. It seems like an easy semi-circular weir problem, but I havent found a source with the equations. I found something called the California pipe method that is promising but it needs 6 pipe diameters of pipe upstream of the free-fall discharge. That doesnt apply since its falling directly out of the hydrant nozzle. They also dont have the option of lugging around a hydrant meter to measure this. Does anyone have an equation or suggestion for determining a flow like this out of a hydrant? thanks

 

[CarlB]

How about estimating the water velocity from the stream trajectory (projectile motion equations),and the stream area from the measured/known depth at the outlet.

 

[bimr]

You still will have to carry some equipment around. See the attachment.


To estimate the discharge from a pumped well from a non-vertical standard pipe by using the trajectory free-fall or jet-flow method.