I put together a short writeup of my project for ME203. Here’s the course description:

Design and Manufacturing
Prototype development techniques as an intrinsic part of the design process. Machining, welding, and casting. Manufacturing processes. Design aspects developed in an individual term project chosen, designed, and fabricated by students. Labs, field trips.

My project is an indoor waterfall with two goals. First and foremost, it should sound like a large waterfall, even though its size should be small. In other words, rather than a gentle “tinkle tinkle” sound, it should make a more Niagra Falls-esque WSSSSSHH sound. Second, it should not splash water everywhere.

If I can nail the sound, then I can worry about controlling the splashing. With that in mind, my prototype focused on creating the sound I’m looking for.

I assumed that the most important factor in the sound would be a combination of water pressure and the height the water fell from (in fact, I think they might be interchangeable). The second most important factor might, I thought, be what the water fell into (in terms of both diameter and water depth). So I began experimenting. I poured water into a medium size vessel (cookware I had in my dorm room) from different heights, and with two different pressures. Pressure didn’t have any effect (probably because I couldn’t control it very well), but height didn’t seem to make nearly as much a difference as I thought it would.

I went on to larger containers, eventually finishing with the largest vessel I could find: a spare trashcan I have. Still, the sound just wasn’t right. I realized that it sounded like turning a faucet on, rather than a waterfall. What do waterfalls have that faucets don’t?

Multiple streams!

So I tried two streams at once, and it worked! I experimented a bit with altering the height, and that did add a bit of volume. But switching between one and two streams, there’s just no comparison: faucet or waterfall.

My next prototype will focus on refining my understanding of why multiple streams makes it sound so much better, and trying to optimize the sound even further. (Are three streams better? Four? Five?)

3 Thoughts to “My project for ME203”

  1. dan

    don’t cross the streams!

  2. Phamburger

    That’s really cool, Greg! Again, I haven’t been around lately. lol. Hope all is going well!

    I noticed that your “waterfalls” are thin in diameter. What about increasing the surface area of the waterfall? Making the waterfall longer covering more ground than single streams? A diver who belly flops will make a huge sound (and splash) compared to the Gold Medal Olympian who cuts through the surface with no splash.

    Every few weeks or so I fill up our 5-gallon water dispenser with five 1-gallon containers. The first 2 gallons always makes much more sound, when there is little water in the 5-gallon dispenser. Maybe it also depends on how much water is in the bucket below?

    ALSO, hehe, when we go fill up our 1-gallon containers at one of those “Water Gourmet” treated/filtered water places, multiple 1-gallon containers filling with water is really loud (when the containers are empty/half empty). Louder is when they push a button that shoots pressurized water into the empty containers to rinse them out.

    And that, my friend, is the observation of an extreme water drinker. =)

    Hope you post progress on your project! Good luck!

  3. tristin

    i’m going to preface this by saying: very cool project! and good on you for figuring that out!

    that said, that second picture looks incredibly wrong…

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