Subject: Centrifugal Forces in a Vortex/Whirlpool

I am trying to create a vortex in a large tank of water. 3M high x 1M diam.
1: How much force I will need to generate a whirlpool in the tank?

2:How strong will the tank will need to be?

I will introduce the energy in to the tank using a centrifuge or water pump.

What is the physics here, and calculations involved. Although I am an Artist I 
studied Math, Physics and Engineering until I was 18 and I make Holograms for 
a living.

My logic so far:-
For a 3M high x 1M diam tank we get a volume of 
Pi*r^2 *3M of Water
= Pi * 0.25 * 3,000 Kg Water
= 2,356 Kg. (5,183 lbs)

Around the circumference of the tank>>
;at the top of the tank we have air pressure.
;at the bottom we have air pressure + 2,356 Kg

If we want a vortex with a volume of 500 litres of Air. 
Am I right in thinking we have to create enough force to lift out 500Kg of 
Water? (For the sake of argument let us allow it to spill over the top of the 
cylinder)

This is where I get a bit lost.

How does the centifugal force add to the outward push?

What is happening in terms of Energy transfer from Potential, Kinetic, Gravity 
and Air/Water Pressure?

How is the rotational speed of the water fit in to this?

Please help.
Thanks, 
Graham T

Re: Centrifugal Forces in a Vortex/Whirlpool