Nice, but does it takes into account that some droplets are directly issued from the hose itself ? Not to mention the double stream problem ^u^
Cool paper nonetheless.
Global sustainability and accessibility seems a bit grandiose lol. It’s just a urinal after all. That being said, it’s been 4 years since Waterloo first determined this and it’s still unavailable to purchase. I’ve been patiently waiting for one to install in my shop but it seems like it’s not all that important for the globe if it’s still unavailable 4 years later.
No amount of engineering can solve the problem that no matter how much you jiggle, you shake, or you dance, the very last drop always falls in your pants.
Sometimes i am using an urinal and i feel like no engineers were involved in the design. Glad to see someone is actually approaching this with proper science.
There is more to it than the splashback tho. Sometimes it seems that the surfaces that already have splashes on them are not angled properly to lead the water to the drain. This seems to create need to have sharp edge/lip rather than round one, which might be tricky to make resilient in porcelain. But the rounded lip certainly allows for droplet flow towards the user rather than the drain hole.
The recent introduction, in the UK at least, of splash-back reducing urinal … mats (?) has basically solved the problem in my opinion. They’re a disposable (but not single use…) plastic freshening insert with loads of short rubber strands, closely packed.
You can pee on one of these mats and the stream almost aerates itself on impact and you get basically no splashback, I guess with a similar mechanism to how an aerating tap produces a stream of water that doesn’t splash off whatever it hits.
Just aim at the sweet spot where your stream smoothly swirls into the plughole. No spray, minimal sound. Most toilets and all urinals have this spot you can hit. In Amsterdam airport they even mark it for you with a crosshairs!
not so long ago it was very fashionable to include DEI/ESG/etc lip service in those things, regardless of whether it made sense. for example, I've read a study comparing leather tanning compounds and it had a completely out of place paragraph babbling about climate change. the author wasn't even American, it's a global cargo cult.
TLDR: The "Cornucopia" has the least amount of splashback, however the "Nautilus" is the recommendation of choice, to accommodate ease of cleaning and variations in the height of the user.
This paper is Ig® Nobel Physics Prize Winner 2026 https://improbable.com/ig/winners/
There is more to it than the splashback tho. Sometimes it seems that the surfaces that already have splashes on them are not angled properly to lead the water to the drain. This seems to create need to have sharp edge/lip rather than round one, which might be tricky to make resilient in porcelain. But the rounded lip certainly allows for droplet flow towards the user rather than the drain hole.
You can pee on one of these mats and the stream almost aerates itself on impact and you get basically no splashback, I guess with a similar mechanism to how an aerating tap produces a stream of water that doesn’t splash off whatever it hits.
I did encounter an upside-down one yesterday. That was... counterproductive.
I suppose this disproves Tufte's "There are only two industries that call their customers 'users': illegal drugs and software."
[1]: https://www.hlwashrooms.co.uk/healey--lord-niagara-urinals--...
[2]: https://acornthorn.co.uk/urinals-wcs-cubicles/urinals/ur068-...
https://academic.oup.com/view-large/figure/512223725/pgaf087...
[1] : https://static.wikia.nocookie.net/dispatch/images/c/ca/Dispa...
What resource will we run out of if we continue to piss in traditional urinals?
Has bullshit marketing terms invaded scientific papers now as well?
https://academic.oup.com/pnasnexus/article/4/4/pgaf087/80987...