Large volume laminar flow machine

[geekengineer]

Could you somehow drill bunch of small holes or micro holes somehow?

Yeah doing a lot of things like that on 3D printer might take you forever for you do all those baffles. I was thinking about that today actually.

 

[karimwassef]

time isn't the issue. It's the cost.

holes or straws only work if they create so much back pressure that the output is forced to be the same.

The problems is that they will be uniform, but low flow.

Uniform at high flow is the target.

 

[geekengineer]

lol yeah.. you need 3 different levels of egg crate.. Anyways.. I shouldn't talk too much since you know much more about it than I do.. I am just a hack at this. I would be the guy that just try things and see what works and what doesn't.. etc.

 

[karimwassef]

We're all learning. I'm not an expert either - I haven't gotten one up and running yet.

Actuated surge - I built up from scratch and improving still - that I know.
Laminar flow - not yet.

 

[geekengineer]

We're all learning. I'm not an expert either - I haven't gotten one up and running yet.

Actuated surge - I built up from scratch and improving still - that I know.
Laminar flow - not yet.

Ah OK I was confused guess since I saw your nice coral picture it looked like was laminar flow. So do you need both actuated surge and laminar flow? or is laminar flow mostly the end goal?

 

[herring_fish]

When water goes over a reef, the flow is mostly laminar but there is some turmulance created as it interacts with what is on the reef. The water that you observe is mostly laminatar but not completly laminar. It just looks and feel that way.

The effect is the same though. So realy good should not be the enamy of the perfect ...and perfect my not be real or a ralistic goal.

I assume that this has been posted already but it is an article about growing Dendronephthya.

https://youtube.com/watch?v=KijVubLbfuM

If you skip down to the section called FLOW, you will see that they made a tank that creates non-oscillating laminar flow. The results a very good considering that they only used 2 pumps and each end to fan out and pressurize the entire plate. Using 4, 6 or more pumps ...or a moving plate, would make is work even better.

The point that I took from it was that they simply used bent Plexiglas in the corners and tied three pieces of egg crate together to act as laminators and got good results. The egg crate formed the square straw sections but did not create the back pressure that I have been so afraid of. This is a cheap and simple solution to part of the problem.

 

[karimwassef]

Ah OK I was confused guess since I saw your nice coral picture it looked like was laminar flow. So do you need both actuated surge and laminar flow? or is laminar flow mostly the end goal?

I believe that I need both and even more. Laminar is key, but my surge is doing a decent job- just not good enough.

 

[karimwassef]

I wish I had called the thread Uniform flow instead of Laminar flow.

I like the dendro article. But the flow is low enough and they allow enough distance and the channels are narrow enough for flow to laminarize.

 

[geekengineer]

Weill I don't know if it really be worth doing in my tank. I just thought it be a bit cute to try it I guess if I ever did try it. It have to be something practical and not take up a lot of extra space etc.

It will be cool to see it implemented in a big tank however I look forward to seeing your solutions if you come up with one..

 

[sculpin2]

Sooooo...

It took awhile, but I have my low tech tidal/bulk flow reef built (pending setup of the controller). It did morph from being a 40B to a 65, but is otherwise the same.

<a href="http://s1170.photobucket.com/user/MBBPhotoZ/media/IMG_1401_zpsgoakpjf2.jpg.html" target="_blank"><img src="http://i1170.photobucket.com/albums/r526/MBBPhotoZ/IMG_1401_zpsgoakpjf2.jpg" border="0" alt=" photo IMG_1401_zpsgoakpjf2.jpg"/></a>
The hardware is all behind the eggcrate.

<a href="http://s1170.photobucket.com/user/MBBPhotoZ/media/IMG_1398_zpsmncrtorh.jpg.html" target="_blank"><img src="http://i1170.photobucket.com/albums/r526/MBBPhotoZ/IMG_1398_zpsmncrtorh.jpg" border="0" alt=" photo IMG_1398_zpsmncrtorh.jpg"/></a>
Here you can see the pumps. There is an identical set on the opposite side of the tank for when the flow reverses. In the "all on" mode, they create a horizontal gyre which is quite impressive. BTW, the RW-8 has to be run on the W2 setting or it will slosh over the edge no matter how slow/weak it is set to.


I have a short video where you can see the microbubbles from the skimmer illustrating the horizontal gyre effect.

 

[sculpin2]

Wow, you can really see the orange peel on the hood in that pic...

 

[sculpin2]

The most realistic wave patterns in the sand that I've ever had in one of my tanks:

 

[Floyd R Turbo]

That's wild

 

[karimwassef]

looks great!!

I think this configuration is still the one you're using?

<a href="http://s1170.photobucket.com/user/MBBPhotoZ/media/IMG_1282_zpsmlekrkde.jpg.html" target="_blank"><img src="http://i1170.photobucket.com/albums/r526/MBBPhotoZ/IMG_1282_zpsmlekrkde.jpg" border="0" alt=" photo IMG_1282_zpsmlekrkde.jpg"/></a>

<a href="http://s1170.photobucket.com/user/MBBPhotoZ/media/IMG_1274_zpsbc8qwqih.jpg.html" target="_blank"><img src="http://i1170.photobucket.com/albums/r526/MBBPhotoZ/IMG_1274_zpsbc8qwqih.jpg" border="0" alt=" photo IMG_1274_zpsbc8qwqih.jpg"/></a>

The horizontal loop is out one side and into the other or is it pushing out of both and circulating back through the middle section?

So when you say all on, do you mean that all four pumps are pushing forward or that two are pushing forward, then stop and then the other two push forward, then stop?

How are the corner angles working out?

 

[karimwassef]

BTW, the RW-8 has to be run on the W2 setting or it will slosh over the edge no matter how slow/weak it is set to.

What's the W2 setting again? Is it sloshing over because the flow is bouncing back from the far wall?

 

[sculpin2]

Karim,

Yes, it is the exact same design (with better plastic work and some frag plug shelves added). I consider the current tank to be Mark 2. I still have the 40B and have considered making it a frag tank.

To answer your question, only one set/side of pumps runs at a time which causes the circular bulk flow. I am actually avoiding chaotic flow as much as possible, unlike how most tanks are designed. As the pumps push the water out, they cause a drop in pressure which in turns pulls water through the opposite grate. When all 4 pumps are running, there is literally a wall of water being pushed around the tank continuously. And, by using 4 small pumps instead of one large pump, I can vary the flow pattern from mild to massive fairly easily. Optimally, this would work best with 4 electronically controlled identical pumps (like the Tunze's) but I wasn't willing to spend a couple of grand on an unproven idea. Maybe on the next tank...

When I say all 4 are on, they are literally all 4 on, three ~1200 gph pumps and one RW-8. In toto, it is probably close to 4000 gph of bulk flow.

I chose to skip on the corner baffles on the Mark 2 build for aesthetic reasons, as it is in the middle of my living room and wifey already is on the edge of her tolerance for home science projects. However, I think that the baffles would improve flow significantly. As it is, even with just the deepest pump running, there is still obvious circular flow at the tank surface.

Mike

 

[sculpin2]

The W1 setting is pulsed flow, which is a big "no bueno" unless I want to slosh over the edge and flood the living room. The W2 setting is the ramp-up-ramp-down setting which is tolerated well.

 

[karimwassef]

Ok. So the pumps are not all the same size and they run on phased timing for ramp up and down. Got it.

Also, the pulses not working indicates that you don't have enough energy in those pulses to overcome the inertia of the wall mass, so you don't get pulsed circulation, you just slosh over.

Interesting and aligns with what I expected. It probably can be related to the viscosity of water and how long it takes to set up a 'wall flow'...

Can you change the ramp up/down to see where the inertia overwhelms the pumps and the circulation doesn't work any more?

Awesome getting it up and running!!!

 

[karimwassef]

Also. Do you think the lower pressure behind the pumps due to the enclosure resistance is handicapping the flow output?

In other words... If you measure outlet flow in an open space vs. in your configuration, do you see a measurable drop? 10%, 15%?

 

[sculpin2]

I don't think there is any decrease in the flow output as the inlet cross section for the back compartment is huge (probably could flow a lot more). The pump outlets are also in a quasi nozzle directed at the main tank, with their inlets being open to the entire back compartment (probably 5-7 gallons of water overall). This helps to prevent local back flow/turbulence and improves laminar flow.

Realistically, this all decreases in efficiency once I put corals and rock in there. However, I'm pretty sure that I will still be able to maintain impressive bulk flow even when you throw all of that biology into my engineering.

BTW, I converted an Aquaclear 110 HOB into a Siporax reactor. It's hidden in the back compartment and contains both sizes of Siporax, as well as Ehein Substrat Pro. I have rows of stacks of Siporax Pond inside of which are stacks of regular Siporax inside of which are Substrat Pro balls. The Substrat Pro balls are there to retard flow, as well as to be media. It took a couple of days of OCD to stack all of that in the HOB. Very curious to see how it works.