Transfer of liquid from one vessel to another

[hazzac]

I am carrying out a feasibility study on whether a site has potential for the installation of an energy production system.

The site is tidal and fills a pond through a sluice once the tide has come in, similar to the picture below.

I need to find the time taken for the pond to fully fill so the head difference is 0. I have been using the below equation, but it takes into account the area of the large container when in reality this is the sea so it is infinite. I could just make A1 extremely large but i'm not sure how accurate this is.

Where:
T = Time to fill (s)
A1 = Area of large container (this is actually the sea)
A2 = Area of pond
H1 = initial head difference
H2 = Final head difference (=0)
Cd = Discharge coefficient
a = area of orifice

 

[LittleInch]

Sorry I'm just not following that equation or really understanding your system.

If A1 is the sea and A2 some pond then where is your energy production? Is it on the water in and out, or only in, or only out? What has area got to do with flow or time?

If only in where does the water in your pond go so that there is room for the incoming tide

The time taken will be difficult to get from an equation as you have changing flow as the tide turns. Tidal height versus pond height is not constant so flow isn't constant and the time taken is there a transient.

Tidal power systems have been well studied and I'm sure there are many sources of data to use for you particular situation.

Usually both A1 and A2 are big in order to maximise flow.

I think you're going to get a very strange answer trying to do it this way.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[IRstuff]

Not sure what your issue with the equation is, but as A1 goes to infinity, the equation simplifies to

t = 2* A2 * (sqrt(H1) - sqrt(H2)) / Cd * a * sqrt(2 * g)

Its form is similar to the draining equation in

https://www.lmnoeng.com/Tank/TankTime.php

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[hazzac]

The 'pond' is actually a mill pond.

The sluice gates are closed and no water is in the system, tide comes in fully, sluice gates are opened and water fills the mill pond through an orifice, the water level reaches equilibrium and the sluice gates are closed.

The tide then goes out whilst the mill pond holds the stored body of water, once the tide is out the sluice gates are opened and the water flows out until empty. The process then starts again.

Thank you for the help with the equation, that has solved my issue.