Discharge length from open ended pipe
Discharge length from open ended pipe
(OP)
Hello,
First time post here! I'm looking for some guidance on how to calculate how far water will discharge from the open end of a horizontal pipe that is gravity draining storm water.
For instance, a 6" diameter pipe takijg water from the roof of a structure, routed vertically down through that same structure, but then taken horizontally for a short distance and discharged to a bioretention area.
The task is to find out how far the water will "shoot" from the pipe when flowing 100 gpm in a 6" pipe by gravity only.
Thanks in advance!
First time post here! I'm looking for some guidance on how to calculate how far water will discharge from the open end of a horizontal pipe that is gravity draining storm water.
For instance, a 6" diameter pipe takijg water from the roof of a structure, routed vertically down through that same structure, but then taken horizontally for a short distance and discharged to a bioretention area.
The task is to find out how far the water will "shoot" from the pipe when flowing 100 gpm in a 6" pipe by gravity only.
Thanks in advance!





RE: Discharge length from open ended pipe
RE: Discharge length from open ended pipe
RE: Discharge length from open ended pipe
RE: Discharge length from open ended pipe
Your issue here is that the water has some velocity and energy when coming down and along the pipe which the water in the tank doesn't have.
The other key issue / problem is that unless the inflow into your horizontal section exceeds outflow rate, your pipe won't be completely full and will glug and surge or maybe just flow out slowly.
Hence you can't find out what the height h is compared to a tank water level.
100gpm in a full pipe is only 0.4m/sec. Not very fast so the distance will be very small.
Storm water by definition is a sudden event and not really suitable for steady state applications.
Water flow into a vertical drain pipe is a well known issue and again it takes a lot of water flow to get the pipe full. a lot more than 100gpm in a 6" pipe.
If its a problem just add an elbow to the end and point it down.... Or add a large pipe ( 12" ) say 1m from the end to slow it down.
You could just do a calc for various full pipe or 50% full pipe velocities and see what you get once you can figure out a way of estimating your max inflow into the pipe using simple velocity and vertical acceleration formuale.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Discharge length from open ended pipe
for vertical flow in pipes like your drain pipe.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Discharge length from open ended pipe
RE: Discharge length from open ended pipe
RE: Discharge length from open ended pipe
RE: Discharge length from open ended pipe
RE: Discharge length from open ended pipe
Here is an another calculator:
https://www.lmnoeng.com/Waterfall/CulvertDischarge...