Every boy needs a project to work on to occupy spare brain cycles. Projects not too complicated have a much better chance of actually be completed (see Nethack Screensaver) than those that are complex (see Rock Band Robot). To that end, I try to also keep things as cheap as possible. Besides, a big budget on a home-brew project is essentially cheating.
So, recently my family found ourselves at the local mall, where they have one of those cool laminar flow fountains. This one wasn't the "jumping" type (though you've probably seen those), but instead a set of "glass rod" type flows of water shooting from a ring into the central pool. The streams were totally coherent, and looked like solid glass. They were accessible by small hands, and after her initial trepidation, Allie had a great time touching the water and splashing about. We were thankful to have brought a change of clothes.
Even before Allie, I've always loved those fountains. At one point (when we were doing landscaping, I think), I looked up how expensive they were. I had big plans of turning our courtyard into a water-feature, with water jumping overhead or some nonsense. Turns out, they are pretty spendy. Thousands of dollars for a single fountain nozzle.
Recently, on a whim, I did some more searching and found that people have been making their own versions that work pretty well. So I'm going to try to make one, too! (Don't ask me what I'm going to do with it yet. I haven't thought that far ahead.)
The basic idea follows thusly: Water is fed from a garden hose into a section of pipe. That section of pipe is much wider (4") than the hose, so the water will travel through it more slowly. Packed into the base of the pipe are some scouring pads. These serve to break up and disperse the incoming flow of water. Following the scouring pads are a set of straws, all jammed into the pipe side by side, forming a "honeycomb" type arrangement (only circular instead of hexagonal). The water is split up and travels through each straw, which serves to straighten out the flow and remove turbulence from the water.
Finally, the water squirts out a hole drilled into a cap that is closing off the other end of the pipe. When the water squirts out, it should all be travelling in the same direction and speed, and should stick together and look like a solid glass rod.
That's the idea, at least. Not too complicated, and nothing too expensive in there.
The details are where it gets a little tricky. For one thing, the straws need to be held in place in the middle of the pipe. People have accomplished this by using a layer of screen (like, from a screen door or window screen) at each end of the batch of straws. And that screen is held in place by a ring that fits snugly inside the pipe. So, you put a circle of screen on the open end of the pipe, and fit the ring into place, and push the whole thing down inside the pipe. Then put in the straws, then another screen/ring combo.
The other final detail is the hole that the water squirts out of. Drilling a straight hole through the end cap may work, but any little burrs of plastic will disrupt the water. I guess water flowing through a drilled hole creates its (Gwen!) own turbulence. So rather than a straight hole, you countersink the hole, so that the water is only passing through a knife-edge thin hole (the countersunk side is on the air-side of the end cap, not the water side).
So, I have all the pieces I need, I think. Just need to assemble and test! I'll take some pictures and let you know (lucky you) how it goes.
For now, you can see what my boy "tedstur" has made, that I'm trying to replicate
http://www.youtube.com/watch?v=QCVV587m4i0
Dream plans would involve a pump that recirculated the water. Most likely, though, this will be used in conjunction with Allie's kiddie pool on hot summer days. Or just to see if it can be done, and sell the plans to Norm for use in his swimming pool. Or something. Who knows. That part doesn't matter much. :)
So, recently my family found ourselves at the local mall, where they have one of those cool laminar flow fountains. This one wasn't the "jumping" type (though you've probably seen those), but instead a set of "glass rod" type flows of water shooting from a ring into the central pool. The streams were totally coherent, and looked like solid glass. They were accessible by small hands, and after her initial trepidation, Allie had a great time touching the water and splashing about. We were thankful to have brought a change of clothes.
Even before Allie, I've always loved those fountains. At one point (when we were doing landscaping, I think), I looked up how expensive they were. I had big plans of turning our courtyard into a water-feature, with water jumping overhead or some nonsense. Turns out, they are pretty spendy. Thousands of dollars for a single fountain nozzle.
Recently, on a whim, I did some more searching and found that people have been making their own versions that work pretty well. So I'm going to try to make one, too! (Don't ask me what I'm going to do with it yet. I haven't thought that far ahead.)
The basic idea follows thusly: Water is fed from a garden hose into a section of pipe. That section of pipe is much wider (4") than the hose, so the water will travel through it more slowly. Packed into the base of the pipe are some scouring pads. These serve to break up and disperse the incoming flow of water. Following the scouring pads are a set of straws, all jammed into the pipe side by side, forming a "honeycomb" type arrangement (only circular instead of hexagonal). The water is split up and travels through each straw, which serves to straighten out the flow and remove turbulence from the water.
Finally, the water squirts out a hole drilled into a cap that is closing off the other end of the pipe. When the water squirts out, it should all be travelling in the same direction and speed, and should stick together and look like a solid glass rod.
That's the idea, at least. Not too complicated, and nothing too expensive in there.
The details are where it gets a little tricky. For one thing, the straws need to be held in place in the middle of the pipe. People have accomplished this by using a layer of screen (like, from a screen door or window screen) at each end of the batch of straws. And that screen is held in place by a ring that fits snugly inside the pipe. So, you put a circle of screen on the open end of the pipe, and fit the ring into place, and push the whole thing down inside the pipe. Then put in the straws, then another screen/ring combo.
The other final detail is the hole that the water squirts out of. Drilling a straight hole through the end cap may work, but any little burrs of plastic will disrupt the water. I guess water flowing through a drilled hole creates its (Gwen!) own turbulence. So rather than a straight hole, you countersink the hole, so that the water is only passing through a knife-edge thin hole (the countersunk side is on the air-side of the end cap, not the water side).
So, I have all the pieces I need, I think. Just need to assemble and test! I'll take some pictures and let you know (lucky you) how it goes.
For now, you can see what my boy "tedstur" has made, that I'm trying to replicate
http://www.youtube.com/watch?v=QCVV587m4i0
Dream plans would involve a pump that recirculated the water. Most likely, though, this will be used in conjunction with Allie's kiddie pool on hot summer days. Or just to see if it can be done, and sell the plans to Norm for use in his swimming pool. Or something. Who knows. That part doesn't matter much. :)
4 comments:
Sweet! You've got the pieces already... I can't wait to bask in the laminar flow.
Hey. Love it.
I thought this video looked very helpful. It appears that all you need is $15, and eight minutes, seven seconds!
http://www.youtube.com/watch?v=OV-IazRk0sU&NR=1
Thanks EJ... that's the first video I saw that really got me fired up on the idea. I'm all over it. :)
Adman I had to do similar flow straightening for my Master's project. To ensure that those little seabass were experiencing similar flow conditions it was important that the flow was laminar throughout my experimental system. I used a similar system, buton a larger scale, and was able to achieve fairly good results, st least until I added fish to the system.
This is a really cool idea you have going, I'm curious to see how it turns out. And if you decide you want to add a pump and some plumbing, let me know, that stuff should be very easy to figure out.
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