Theoretical Flow

[Mekanic]

Now.. I was sitting here and had a thought..

When it comes to the Tunze Wavebox, everyone agrees that it moves the entire tank volume with no dead spots, but no one can agree on the flow it pushes. SO!! I decided to do a little theoretical math on my 6212.

Now this is based on the fact that no one disagrees that the Wavebox moves the ENTIRE tank volume around. So based on that, I came up with this...

On my standard 90g tank, my 6212 wavebox oscillates at 94 alternating waves per minute.

With my tank volume being 90g, and the wavebox moving the entire volume, it stands to reason that 90g of water is being moved 94 times per minute.

Which with some multiplication comes to 8,460 GPM, or 507,600 GPH..


Beat that ... other company!!!

~Rich

[gbru316]

I'm not sure this is correct.

my guess is that wavebox isn't physically moving 507,000 gph THROUGH it. The movement of water through the box is causing the rest of the tank to move, although the amount of movement in the tank probably can't be measured the same as the laminar flow provided by a powerhead, because it's not laminar flow.

I'm not even sure it can be considered flow, as it's sinusoidal in nature. Providing no obstructions or friction, any movement forward would be offset by an equal movement in the reverse direction. Sure the water is moving, but it's not flowing.

Then again, my background is electronics. This is a question better suited for someone who regularly deals with fluid dynamics.

[Allmost]

hello felow math geek :)

good line of thinking, but you are calculating a 90 Gallon displacement, whole tank water might move, but they do not move 1 90G aquarium each, they move maybe a couple of inches :)

sooooo to correct your calculation.
lets say you get 1 wave per second, 60 waves per minute and 3600 per hour.

lets say in a 90 G tank, you get a 2" wave. assuming the 90G is 24" high, the VOLUME of the wave is now 7.5 Gallons.

sooooo, you have 7.5 * 3600 = 27000 GPH of water is actually moved/displaced :)

about other companies taking that ..... all Wave makers, make wave, and hence same calculation can be used for it :)

[Allmost]

I'm not sure this is correct.

my guess is that wavebox isn't physically moving 507,000 gph THROUGH it. The movement of water through the box is causing the rest of the tank to move, although the amount of movement in the tank probably can't be measured the same as the laminar flow provided by a powerhead, because it's not laminar flow.

I'm not even sure it can be considered flow, as it's sinusoidal in nature. Providing no obstructions or friction, any movement forward would be offset by an equal movement in the reverse direction. Sure the water is moving, but it's not flowing.

Then again, my background is electronics. This is a question better suited for someone who regularly deals with fluid dynamics.

na Im an electrical eng too :) we can do it :)

you need to get the integral [area under the curve] of the absolute value of the Sin Wave, from one side of the wave to the other ! that's the total water displaced :)

which is NOT how much water goes through the wavemaker as you correctly pointed.

[Mekanic]

Correct, this was not a calculation on how much water flows through the wavebox, but a measure of how much water the wavebox displaces over a given time.

Allmost, you are correct about getting under the curve of the sine. My initial math was indeed off.

Even woth your corrections in place, factoring a 2" wave, and my being really bored and counting 94 waves per minute, would equate to 42,300.

That said, just to make sure my brain is correct now, although we are only making a 2" wave in the math, the entire volume of the system is still being displaced by 2" on each oscillation, no?

[gbru316]

Correct, this was not a calculation on how much water flows through the wavebox, but a measure of how much water the wavebox displaces over a given time.

Allmost, you are correct about getting under the curve of the sine. My initial math was indeed off.

Even woth your corrections in place, factoring a 2" wave, and my being really bored and counting 94 waves per minute, would equate to 42,300.

That said, just to make sure my brain is correct now, although we are only making a 2" wave in the math, the entire volume of the system is still being displaced by 2" on each oscillation, no?

you've got frequency (roughly 1.5 hz), amplitude (2"), what about wavelength? Using 1.5 hz (94 waves per minute to roughly 1.5 cycles per second), 1 wave would be 6.5571e+8 feet. Unless your tank is 655710000.0 feet wide, you're not experiencing a full sine wave, correct?

So the water movement would be a fraction of the movement experienced by a full sine wave.

I could be way off base here, my calculus is restricted to calc 2 at the moment, and I haven't taken physics relating to waves at the college level yet. Last physics of waves I took was high school, 11 years ago.

[Allmost]

Correct, this was not a calculation on how much water flows through the wavebox, but a measure of how much water the wavebox displaces over a given time.

Allmost, you are correct about getting under the curve of the sine. My initial math was indeed off.

Even woth your corrections in place, factoring a 2" wave, and my being really bored and counting 94 waves per minute, would equate to 42,300.

That said, just to make sure my brain is correct now, although we are only making a 2" wave in the math, the entire volume of the system is still being displaced by 2" on each oscillation, no?

I would think of it as each water molecule moving by 2". so yes, the whole volume moving, by 2" ... if that made sense lol

of course maybe not every single molecule would move .... but you know what I mean :)