Ripple Tank - Plane Waves

[rhizotron]

Ripple Tank - Plane Waves

This project is a continuation in series of setups incorporating physics principles and mechanical devices with model ecosystems...

Gantry Water Ripple Generator
Traveling Water Wave Machine
Electromagnet Ripple Generator

The core idea is to specifically engage the water itself as a dynamic aquascape element along with the live plants, substrates and livestock.

The mechanism for the current project is very simple: a small electric motor spinning an eccentric weight energizes a straight bar suspended at the water's surface. This configuration generates straight, parallel ripples, also known as plane waves. Here's a video with this kind of ripple generator used for experimental and educational purposes.



With the idea of keeping the DC motor safely up and away from the water, this project is using a modified mechanism. Here's the prototype built with wood dowels, rubber bands and other parts. A microcontroller with L298N brushless driver run the motor.

Pretty rustic, but it took me all night to get that running.

Here is the updated version with woven graphite tube, plastic fittings and a clear plastic tube.

If I can get some other things off my desk I hope to set up the tank this evening, so I might have an update to share a bit later. This setup will be freshwater with some easy nano fish and small carpeting plants, but you can also imagine a shallow lagoon-style marine tank incorporating this idea.

Thanks for reading! More pretty soon...

 

[tzabor10]

Amazing to see. I look forward to seeing applications someday.

 

[rhizotron]

Amazing to see. I look forward to seeing applications someday.

Thanks for stopping by!

I hope to have water in the tank tonight for a test.

 

[TangerineSpeedo]

Always love your practicals! Thanks for sharing.

 

[Jmp998]

Very cool. Big question is the extent to which this is actually better for artificial care of corals etc, vs. just 'appearing more natural' compared to standard powerheads. Regardless this is the kind of project which may potentially advance and transform the hobby and coral care in general. Awesome that you are doing this and sharing your experience.

 

[rhizotron]

Always love your practicals! Thanks for sharing.

Thanks as always for stopping by!

Very cool. Big question is the extent to which this is actually better for artificial care of corals etc, vs. just 'appearing more natural' compared to standard powerheads. Regardless this is the kind of project which may potentially advance and transform the hobby and coral care in general. Awesome that you are doing this and sharing your experience.

For this particular concept the practical application aside from the decorative appeal might be limited because energy for these short-wavelength ripples just doesn't propagate very deep. But it looks those other concepts using larger paddles certainly could be of use for coral and other livestock husbandry.

These ideas also provide more layers of opportunity for engaging the aquarium as a biophilic design element, especially with water caustics effect expanding the aquarium into much more of the interior space.



I really need to get some better video but here's a quick Instagram reel to demonstrate this. Another cool thing to add (also under development here) are user interfaces to provide control over the ripple/wave generation and lighting.

 

[Gumbies R Us]

These are always amazing to watch!

 

[rhizotron]

These are always amazing to watch!

Thanks!

I got a quick Instagram video up. No fish or plants in the tank yet, but you can get an idea of the hardware setup and the water caustics effect on the ceiling. Tank is DIY and about 36" X 12" X 7", so about 13 gallons.

 

[rhizotron]

I just ran into a more recently uploaded ripple tank video I had not seen previously. This one offers a more thorough demonstration of physical principles with varied dipper configurations. The ripple generator is a DC motor with mini cam & follower mechanism.

 

[TangerineSpeedo]

It would be interesting to use a waterproof speaker to see if you could create a more dynamic or curated wave response. Or multiple speakers to watch the waves combine or cancel each other out.

 

[Northern Flicker]

Tank manufacturers watching this and imagining the possible stresses home users will be putting on their seams in the future:

 

[rhizotron]

Tank manufacturers watching this and imagining the possible stresses home users will be putting on their seams in the future:

LOL. No. This is very little energy. These are tiny ripples.

 

[rhizotron]

It would be interesting to use a waterproof speaker to see if you could create a more dynamic or curated wave response. Or multiple speakers to watch the waves combine or cancel each other out.

Yes the other style of research/education ripple generator uses an electromagnet transducer + sine wave generator to move the dipper.

External vibration generator for PHYWE Ripple Tank

Here's an artist who uses a mechanism like this with polished steel bowls for water caustics effects.



He has resolved the point-source lighting and input/output well.

For my model ecosystem setups, I've found that varying the wave generation is essential because a constant ripple frequency has a visually unpleasant hypnotic effect. For the electromagnet dipper on the 24" X 24" tank this was easy to achieve by just varying a half-dozen HIGH and LOW delays to run on a loop.



I haven't gotten around to it yet, but I need to also vary this new project's motor spin for more varied ripples traveling down the tank. This should be easy to do with the L298N motor driver.

 

[rhizotron]

I got the tank aquascaped with a simple stone layout, plants and fish. It would look better with more variety of rounded lava stone sizes and I might buy another bag in the 1"-2" size. I had hoped for better water caustics definition on the sand, but the effect on the ceiling is pretty nice.

Here's a quick Instagram reel.

 

[rhizotron]

Some pics also...

That Kessil A80 with gooseneck went together really nice with the other parts and it's the perfect lighting for this setup. I lucked out.

I have an idea for better ripple definition, but this mellow water motion is nice for this fish combination. A future update will also replace this rather contrived aquascape with something more naturalistic. But I like this for now. That orange reptile sand and fireplace stones goes nice with these fish.