- #1

Diokhan

## Homework Statement

: See below paragraphs[/B]## Homework Equations

: I'm not sure on which equations I need.[/B]## The Attempt at a Solution

: I'm so sorry, this really isn't my strong point. Using the figures below, the tank surface is 113.184 sq in. The side pipe has a cross section area of 3.14 sq in. The water height in the tank needs to be 42" which is 1.0668 meters and I don't know what to do next. Please see paragraphs below.[/B]I was asked to post this here and not in the technical section, however this isn't homework or coarse work. I'm 37 years old and have been out of school for 20 years. I am engineering a series of gravity driven bioreactors for aquaculture and I need help calculating what height the exit pipes need to be based on the following situation:

There is cylinder column of water in a tank of a known diameter. Water enters from above at a known flowrate. Water exits out the bottom through a pipe of a known diameter, and this exit pipe routes up the side of the tank to a known height so that as water enters the tank, it stays at a known height.

For some example numbers to plug in - the tank is 12" diameter and 48" tall, water enters from above at 30 gpm, exits through a 2" pipe. Water needs to remain 6" from the top of the tank. At what height does the exit pipe outlet need to be?

I really don't know how to solve this, though I'm sure that Bernoulli's equation comes into play. I've been able to find many examples where water just exits out a hole of a known diameter at the bottom while the tank fills, but not where water enters from the top while exits out the bottom, routes through a pipe, then exits at a known height.

Please show all work. I would like to turn this into an excel spreadsheet so that I can play with different flowrates, tank diameters, tank heights, exit pipe diameters, and the height of water from the top of the tank. I will always be solving for the height of the exit pipe.

THANK YOU ALL!