What are your thoughts on a vortex commonly refered as a Whirlpool

DRC Archive General Saltwater Discussion
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[quote=“a1amap, post:20, topic:1072”]
I thought of another idea that I was going to attempt to create some chaos in the water column. Have one pump going one direction and a couple hours later it would shut off as another pump facing the reverse direction start. Almost tidal and would reduce any coral growth issues often associated to laminar flow. (may or not be true)[/quote]

Thats what I was talking about. Vortex going one way (from back left front right) then switch to vortex going the other way (back right front left). You get the best of both worlds

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[quote=“a1amap, post:20, topic:1072”]
Ian, having the pump up high reduces the amount of water it has to move before the vortex starts. Once started it will carry through the water column and the entire tank will move. It should not be breaking the surface.[/quote]

But time taken to start it doesn’t matter as much as over all flow.

Ken if you spun the middle CD as much as you spun the top cd you would have a more even speed of cds throughout the stack, but the over all speed of cds spinning.

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Ian, Ken is saying it takes less energy to start the top spinning then the middle or bottom. Take his cd example and spin the top cd, it flies. Now try to move the center disk. Since all the disks above are pressing on it and there is friction created above and below with the other disks it takes more energy to move. The bottom cd takes the most energy and has the entire weight of the stack and friction from the base to overcome. Now once it overcomes this friction and the vortex is created it will reduce the energy needed to maintain but will still require more energy then just below the surface.

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I dunno Al, still not sold on the science behind it.

Either way I think the dual vortex wave maker idea would rock! I’ll maybe give it a shot.

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yup, two maxi jet pump mods would really do the job.

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Ian, you are right to question some of the science behind it.

That does not mean that it is not better for the tank. It very well may be just not for the reason listed.

kaptken is correct that the surface is easier (read uses less energy) to get spinning than the middle due to friction (air water boundry is considered frictionless).

Coriolis Effect (or coriolis force as the effect is just the preception of the force) does not effect the flushing of toilets, draining of sinks, etc. The force is so small that the geometery of the bowl overrides it.
http://en.wikipedia.org/wiki/Coriolis_effect scroll down to the “Corrections to common misconceptions about the Coriolis effect” part.

[glow=red,2,300]WARNING[/glow] from here on I am geeking out and most people’s eyes will glaze over. >LOCO< (We need some sort of geek smiley cause crazy is close but yet so far away)

You asked for it, you got it … :GEEK:

It also only applies to a rotating frame of reference (i.e. the earth, turntable spinning, merry-go-round). Lets assume none of us have spinning tanks. You could set your frame of reference so instead of say the back left corner of the tank as you would using rectanguler cooridinates (x,y,z) at the center of the rotation (somewhere is the middle of the tank) but this will make what happens at the tank walls really complicated.

There is some confusion between speed and velocity (velocity is a vector and speed is not).

The angular velocity is the same no matter how close you are to the center of rotation but the velocity (in x,y,z) is different. If someone really wants to know the differential equations to convert one to the other I am sure I can get them to you but if you actually care you probably have access to a physics book of some sort that has them.

I am looking for a cool picture there is one in my one book of what happens to the flow in a rectangular tank when the flow in the center is rotating.

Anyway, all of that aside it may be better for the corals. Crashing the output of the powerheads into each other is not an effient use of energy. Some compromise of the two probably is.

[quote=“IanH, post:24, topic:1072”]
Either way I think the dual vortex wave maker idea would rock! I’ll maybe give it a shot.[/quote]
That just sounds cool. If it is how I am thinking it would rock.

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MiniMomma…it appears you are a dork like the rest of us!

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Guilty as charged.

Like I said we need a geek or dork smiley.

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[quote=“IanH, post:27, topic:1072”]
MiniMomma…it appears you are a dork like the rest of us![/quote]

Soo much dorkier then me.

Minimomma you owe me $12 for the keyboard I busted when i fell asleep and broke mine with my forehead.

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Hey at least I gave a warning.

[quote=“MiniMomma, post:26, topic:1072”]
[glow=red,2,300]WARNING[/glow] from here on I am geeking out and most people’s eyes will glaze over. >LOCO< (We need some sort of geek smiley cause crazy is close but yet so far away)

You asked for it, you got it … :GEEK:[/quote]

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WOW! I’m glad to see The Geekyness abounds. Not many today spend the time or effort to really dive into a question below the surface, so to speak. That’s the problem with America today, nobody really can or wants to do the math anymore. Not to say i can still do the math, but just still have a general understanding. I leave the math to younger folk as my memory is fading.

yes, the coriolis effect comes from FLOW of water from a still vessel perpendicular to the angular motion , or rotation of the earth toward the center of gravity. Something to do with that pesky RIGHT HAND RULE OF ROTATION in physics class, but being left handed, im always confused. it is in our tanks, but without the drain. . still, an induced counter clockwise(for our hemisphere) rotation would induce a downward flow in the center of the tank. helping it along.

a circular tank would make the geometry of flow simple. but rectangular tanks would probably induce small local eddy currents near the corners, if the tank were void of obstructions. adding rock and corals, only complicates the flow.

putting two pumps in opposite corners, opposed to each other would create a null zone of reflection in the center, and less flow over all, with more dead spots.

So, two pumps, flowing in the same counter clockwise rotational direction should induce more flow throughout the tank. That was the experimentally measured results of this speakers experiments. the result being greater flow over more of the corals in the tank, which induces greater gas and nutrient exhange with the water to promote coral health and growth.

Caotic, pulsing flow in the tank is better created by something like the WAVE-2K rather than just opposed pumps. In my analysis. or even better, combined with pumps rotating in the same direction!!

Hey, anyway to shrink my old friend down for the GEEKINESS icon?

He’s my Hero!!