Large volume laminar flow machine
- Thread starter karimwassef
- Start date
ericarenee
New member
This Could Work Quite well... But I just do not see how to get the volume of water to spin and Keep Fish away from the Paddles..
Unless the paddles themselves were part of the decor of the tank There speed would only need to be very slow if sized right.. Coral shape paddles ?????? Anything you did to protect them like screen or a shroud would also defeat the water movement ....
I do not like Cylinder tanks...
But i do have a Octagon tank in the basement.. its like 40 something gallons i think...
karimwassef
Active member
Why?
Imagine a black fence that allows water to move through it. The paddles would be less effective but it should still work.
karimwassef
Active member
The reason I think circular is the answer is because it pulls and pushes at the same time.
Thick of a egg beater paddle in soup. After a couple of cranks, everything is going around.
Or a spoon in coffee.
The cylindrical shape takes energy in many directions and coverts it to rotational flow. It's a natural channel.
Thick of a egg beater paddle in soup. After a couple of cranks, everything is going around.
Or a spoon in coffee.
The cylindrical shape takes energy in many directions and coverts it to rotational flow. It's a natural channel.
ericarenee
New member
I agree.... and with a much less powerful motor.
Will fish go mad swimming in Circles in a Round TANK...?:rollface::rollface::rollface:
Sorry have to ask....:fun4::spin1:
Gorgok
New member
I can get the entire body of water moving in a 18'x 4-1/2' round pool moving with just a pair returns pointed in the same direction on the wall... you don't need paddles. I don't even think the returns are much in terms of flow. It just takes time. Bigger returns in a much smaller tank would do it much quicker, though with a whirlpool like that you end up with a higher water level on the outside than in the center...
Circular tanks have their own issues though, which is why i think a racetrack with a thin center wall would be a decent enough compromise. Again i would use returns or powerheads for the motion, and just let it build up, instead of trying to force it to happen in ~5 seconds.
Circular tanks have their own issues though, which is why i think a racetrack with a thin center wall would be a decent enough compromise. Again i would use returns or powerheads for the motion, and just let it build up, instead of trying to force it to happen in ~5 seconds.
karimwassef
Active member
Thanks erica and Gorgok.
I think that powerheads do an adequate job, but they don't achieve the bulk laminar flow I experienced.
I think time does matter. My tank has amazing wave action and flow, but the impact of this bulk alternating flow is different. It creates little stress but continuously moves and refreshes the polyps.
I like jacuzzis. I like wave pools. But the sensation in the reef is neither.
By the way, I'm not talking about a vortex. The flow around the inner wall will be faster, but not more than a powerhead's max speed. The fish won't get dizzy.
The reality is that their natural environment is like this.
The bulk flow doesn't need to be the only flow. It's also not always on either.
I'm wondering what shape paddle wheel would be most effective (fast) in creating a smooth laminar circular flow with the least energy.
Someone must have done this for another application already.
I think that powerheads do an adequate job, but they don't achieve the bulk laminar flow I experienced.
I think time does matter. My tank has amazing wave action and flow, but the impact of this bulk alternating flow is different. It creates little stress but continuously moves and refreshes the polyps.
I like jacuzzis. I like wave pools. But the sensation in the reef is neither.
By the way, I'm not talking about a vortex. The flow around the inner wall will be faster, but not more than a powerhead's max speed. The fish won't get dizzy.
The reality is that their natural environment is like this.
The bulk flow doesn't need to be the only flow. It's also not always on either.
I'm wondering what shape paddle wheel would be most effective (fast) in creating a smooth laminar circular flow with the least energy.
Someone must have done this for another application already.
herring_fish
Crazy Designer
ericarenee I visited Louisville but I did live in Lexington. '90 to about '94 That's where I got my first reef tank.
Ok back to the problems at hand.
Plenty of people have done laminar flow tanks before, long and short raceway tanks, raceway tanks that go up and over instead of going to the back, round tanks, yep.
The problem is laminar --- alternating flow. Then you throw in the 0 to 60 in 16 seconds. Well 1 inch per second but without being su, su, sinusoidal.
So, powerwise, you are looking for something more like square a wave than a sine wave right?
I don't remember the size of your tank but are we talking about 2000 pounds of water stopping on a dime?
Just keep'en it real here for a moment. Can we compromise on any of these points?
Ok back to the problems at hand.
This is a comment to laugh at but it might be easier to oscillate the coral bed, back and forth against standing water than moving the water.
Plenty of people have done laminar flow tanks before, long and short raceway tanks, raceway tanks that go up and over instead of going to the back, round tanks, yep.
The problem is laminar --- alternating flow. Then you throw in the 0 to 60 in 16 seconds. Well 1 inch per second but without being su, su, sinusoidal.
So, powerwise, you are looking for something more like square a wave than a sine wave right?
I don't remember the size of your tank but are we talking about 2000 pounds of water stopping on a dime?
Just keep'en it real here for a moment. Can we compromise on any of these points?
karimwassef
Active member
I think sinusoidal is ok. While it didn't feel sinusoidal, working through the math when I was looking at the wave forms, I can see that the frequency and speed of the flow will be close to my experience even with a sinusoidal excitation.
It's also the easiest way to avoid crashing waves.
A smooth transition to zero and reversal will only be possible with a sine.
This also works well with a large motor and a circular tank.
I haven't done the works on the equations yet. I think a mock up is pretty easy in this case, so I might do that first.
It's also the easiest way to avoid crashing waves.
A smooth transition to zero and reversal will only be possible with a sine.
This also works well with a large motor and a circular tank.
I haven't done the works on the equations yet. I think a mock up is pretty easy in this case, so I might do that first.
karimwassef
Active member
New terms: coating and rimming flow
http://eprints.maths.ox.ac.uk/1564/1/finalOR61.pdf
Not quite the same thing, but may be relevant.
http://eprints.maths.ox.ac.uk/1564/1/finalOR61.pdf
Not quite the same thing, but may be relevant.
karimwassef
Active member
Another term: circular couette flow
https://uwaterloo.ca/applied-mathem...nics-students/amath-463-students/laminar-flow
https://uwaterloo.ca/applied-mathem...nics-students/amath-463-students/laminar-flow
karimwassef
Active member
To be clear, I don't want to set up surface waves or standing waves by pushing flow and have it bounce back from the opposite wall. I want the entire volume to shift to the left and then to the right. No waves.
What is the point of anonymously copy-pasting the same sentence that you don't understand?
karimwassef
Active member
Thank you
karimwassef
Active member
ericarenee
New member
Nice i will read this later...
Right now i am planing out my New Fuge.. Its going to be a Bit over 6 foot long Made out of a 55 gallon drum split. Its that or start selling Plants . As my Current Fuge is way over grown.....
Going to turn the current fuge into a Frag tank.......
karimwassef
Active member
Nice. I just use a 100g Rubbermaid.
Selling plants? Like macro?
So I'm working out the formulas for this tank and the wheel design.
I'm thinking of a 10ft diameter, 2ft high tank. The paddle wheel (or impeller) is 4ft tip to tip with a 1ft round center. Each of the blades is then 1.5ft.
It's driven by a DC motor above the tank.
The impeller's central shaft also doubles as the overflow...
The way this works is : the tank's overflow is an 11" cylinder that's 22" high in the middle of the tank. The impeller is a 12" pipe with the blades attached. The 12" pipe fits around the 11" overflow like a wheel on an axle.
The impeller's shaft has a 3" opening that runs between the blades right at the overflow level.
At the 4ft diameter, a black plastic grate is shaped like a cylinder. The top is covered to prevent light from getting in.
The coral area is th annulus remaining. It's 3' deep x 2' wide and goes around the length which is around 31ft. That's about 1000gal of usable tank. The impeller and overflowing occupy another 200gal in the middle.
I'll draw it up.
Selling plants? Like macro?
So I'm working out the formulas for this tank and the wheel design.
I'm thinking of a 10ft diameter, 2ft high tank. The paddle wheel (or impeller) is 4ft tip to tip with a 1ft round center. Each of the blades is then 1.5ft.
It's driven by a DC motor above the tank.
The impeller's central shaft also doubles as the overflow...
The way this works is : the tank's overflow is an 11" cylinder that's 22" high in the middle of the tank. The impeller is a 12" pipe with the blades attached. The 12" pipe fits around the 11" overflow like a wheel on an axle.
The impeller's shaft has a 3" opening that runs between the blades right at the overflow level.
At the 4ft diameter, a black plastic grate is shaped like a cylinder. The top is covered to prevent light from getting in.
The coral area is th annulus remaining. It's 3' deep x 2' wide and goes around the length which is around 31ft. That's about 1000gal of usable tank. The impeller and overflowing occupy another 200gal in the middle.
I'll draw it up.
ericarenee
New member
I have done the rubber maid tank .. The reason i like the barrel idea is the rounded bottom.. Lots of surface area with less water volume..sediment should setting in the middle at the bottom....
10 FOOT Radius tank.. wow Ambitious.... Cant wait to see .. I do think it will work
karimwassef
Active member
Moved to 8ft.
Playing around with the variables. I like the final version here.
<iframe width="560" height="315" src="https://www.youtube.com/embed/p69tsrWjX00" frameborder="0" allowfullscreen></iframe>
Playing around with the variables. I like the final version here.
<iframe width="560" height="315" src="https://www.youtube.com/embed/p69tsrWjX00" frameborder="0" allowfullscreen></iframe>
herring_fish
Crazy Designer
(Edit: I put this together tonight before reading several posts so I am behind before I get started. I posted this and then read back. I will just leave it as is. Some of it fits what you are talking about.)
I thought that I would add just a little more detail to what I was talking about earlier. These ideas could be applied to straight raceway tanks or cylindrical tanks. This could get you close to what I think that you want.
There is a wide variety of rails and carriages. These are linear.
These are curved so you could use them on a circular tank.
The action of this simple drive piston pushing a wheel converts straight motion into circular. We could turn that around and get a motor driven wheel to push a carriage either linearly or around an 1/8th circle. I think that this will save electric power because the motor can run at a steady state. I am not sure because that is another area that I know nothing about.
Four paddles could be placed parallel to each other. Plexiglas sides would keep the paddle pointed straight down and not allow them to bend as they are dragged through the water. There would be sides but no top or bottom. The box of paddles would be just small enough to miss the walls by a very small margin.
This box of paddles could be attached to the carriage to be moved back and forth by the rod and motorized wheel.
If you have the divider in the center of the tank, the paddle would only need to move 4 inches. If the divider is at the 1/3rd mark, then I think that the paddles would move 8 inches.
In either case, that is not too far. I also think that the more paddles that you have the less unwanted wave action you will get at those paddles.
This would be true if you had a round tank with paddles that are arranged like spokes in the back part of the tank. In this case, the paddles would be visible but not brake a plain that divide the front and back halves of the tank. They would be strengthened with a Plexiglas top and bottom.
Below I have a drawing that is very rough so you still my not be able to follow what I have in mind. Hopefully, you can see that I tried to draw the carriage over the back half of the tank and the paddle box extending into that half. Above it all is the motor, wheel and drive rod that is attached to the carriage.
I thought that I would add just a little more detail to what I was talking about earlier. These ideas could be applied to straight raceway tanks or cylindrical tanks. This could get you close to what I think that you want.
There is a wide variety of rails and carriages. These are linear.
These are curved so you could use them on a circular tank.
The action of this simple drive piston pushing a wheel converts straight motion into circular. We could turn that around and get a motor driven wheel to push a carriage either linearly or around an 1/8th circle. I think that this will save electric power because the motor can run at a steady state. I am not sure because that is another area that I know nothing about.
Four paddles could be placed parallel to each other. Plexiglas sides would keep the paddle pointed straight down and not allow them to bend as they are dragged through the water. There would be sides but no top or bottom. The box of paddles would be just small enough to miss the walls by a very small margin.
This box of paddles could be attached to the carriage to be moved back and forth by the rod and motorized wheel.
If you have the divider in the center of the tank, the paddle would only need to move 4 inches. If the divider is at the 1/3rd mark, then I think that the paddles would move 8 inches.
In either case, that is not too far. I also think that the more paddles that you have the less unwanted wave action you will get at those paddles.
This would be true if you had a round tank with paddles that are arranged like spokes in the back part of the tank. In this case, the paddles would be visible but not brake a plain that divide the front and back halves of the tank. They would be strengthened with a Plexiglas top and bottom.
Below I have a drawing that is very rough so you still my not be able to follow what I have in mind. Hopefully, you can see that I tried to draw the carriage over the back half of the tank and the paddle box extending into that half. Above it all is the motor, wheel and drive rod that is attached to the carriage.
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