gravity flow thru opening

[saabnut1]

I'm looking for a chart that would give me gravity flow of water thru different size circular openings. for example. I have a 500 gal tank with a 2" hole in the side. What gpm flow can I put in the tank where the water level in the tank will never rise above the top of the hole. Please help

 

[amorrison]

1. Try this for a guide

http://www.pondarama.com/html/pump_to_waterfall_sizing.html

2. Search Google using "weir"

3. Ask the civil groups -it should be trivia for them

4. Check out a basic book on fluid mechanics

 

[saabnut1]

Thanks for the link but I think their estimates are very conservative. According to my calculations from their chart, using cross section area a 2" circle will allow 6.8 GPM thru it, and a 3" hole will allow 15.2 GPM. Does this sound right

 

[PEDARRIN2]

I believe it depends on the height you want to maintain. I remember the solution of this was an integral which related the diameter of the tank, the diameter of the hole and the elevation difference between the fluid surface and the hole. I do not remember the exact equation, but do remember that height of the fluid affected the flow rate out of the hole.

 

[saabnut1]

I do not want the fluid level in the tank to rise above the hole more than 2 inches. for ref lets say the dia of the tank is 4 ft

 

[Montemayor]

Saabnut:

You fail to give us all the basic data required to resolve your problem. I'm going to assume the tank is an open tank and the outlet pipe on the tank's side is a vertical, gravity drain overflow. If that's the case, then go to thread378-87442 on this forum and read my post on the subject. The Hill article gives a series of curves for different configurations and I've regressed them into equations for quick and easy resolution and programming, if needed.

I believe this will resolve your problem. Good luck.