(Phys.org) —A team of four physicists at Brigham Young University (calling themselves "wizz-kids") has been studying the physics properties of urine splash-back in a urinal-like environment. Their mission was to uncover the fluid dynamics involved in male peeing and to hopefully discern which approach leads to the least amount of splash-back (and less mess). They will be presenting their results at the American Physical Society Meeting later this month.
It's a problem males have dealt with since the advent of clothes and porcelain toilets—letting fly at the urinal inevitably results in some splash-back onto the floor, or worse, trousers. To better understand the problem, the team at BYU set up a water tank and nozzles (emitting colored water) to mimic the natural flow of human urine as it leaves the body. They then filmed the action using high-speed cameras. Scrutiny of the video allowed the team to clearly see which sorts of techniques cause the most, or least splash-back. They also set up another tank to mimic sitting on a toilet to pee, rather than standing at a urinal.
In analyzing their results, the researchers found that sitting on a toilet, as most men well know, results in the least amount of splash-back (the contact point is much closer). They also discovered something likely few men have considered—that urine follows what is known as the Plateau-Rayleigh instability—where a pee stream breaks up into drops before striking something else. That's the worst thing that can happen, the team reports, because each drop creates splash-back. To avoid that, men should stand as close to the urinal as possible they advise. Also helpful is directing the stream to hit the back of the urinal at a downward angle. That creates less splash-back and the drops that do bounce, head downwards into the urinal drain. Conversely, to prevent messing one's trousers (or angering neighbors) they suggest men not spray directly into the urinal or into the pool that forms at the bottom of the urinal, both cause a lot of splash-back.
The team also report that they also found that many detergents used to clean urinals tend to make the problem of splash-back worse because it reduces surface tension. Thus dirtier urinals might be less messy.
Explore further:
'Toylets' games make a splash in Japan urinals
More information: 1. The presentation, "The Hydrodynamics of Urination: to drip or jet," is at 5:24 p.m. on Sunday, November 24, 2013 in the David L. Lawrence Convention Center Room 333. ABSTRACT: meeting.aps.org/Meeting/DFD13/Event/202555
2. The presentation, "Urinal Dynamics," is at 5:11 p.m. on Sunday, November 24, 2013 in the David L. Lawrence Convention Center Room 333. ABSTRACT: meeting.aps.org/Meeting/DFD13/Event/202554
ViperSRT3g
2.2 / 5 (17) Nov 07, 2013verkle
Nov 07, 2013comma
3 / 5 (6) Nov 07, 2013To be fair, you didn't know anything; you merely believed your assumptions to be correct after what you believed to be a lot of visual evidence. But the goal of science is to advance knowledge, not assumption. So to have physicists verify information you believed, but never knew, is still quite useful.
rnagerdanger
not rated yet Nov 07, 2013rkolter
3.9 / 5 (7) Nov 07, 2013MikeBowler
1 / 5 (2) Nov 07, 2013Humpty
1.8 / 5 (15) Nov 07, 2013The students FAILED on some things, the piss hole is not actually round, it's flat, and it has a spiral kind of shape that puts a spin on the piss.
Sometimes dried cum can glue your dick a little bit shut so you can piss in two directions at once.
And sometimes the aim is just not quite straight.
The problem is that park bench style shitters were NEVER designed to be pissed into... they were the fore runners of the septic system with the night soil cart... and the shit cans.
The fundamental design for MEN and PISSING is wrong.
We NEED to restore the Glory of the Mans Urinal to it's glorious status - as "The Place to Be, and The Place to Pee." (tm me)
This is WHAT WE NEED.... and to get the fundamental equation right - we NEED proper pissing places. The shit holes are not for pissing in.
http://farm6.stat...ec47.jpg
Zera
1 / 5 (11) Nov 07, 2013TheGhostofOtto1923
1 / 5 (3) Nov 07, 2013"They will be presenting their results" -I wonder if this is in the form of a demonstration? Perhaps it would be something like this
http://www.youtub...a_player
h20dr
1 / 5 (9) Nov 07, 2013[
q]
To be fair, you didn't know anything; you merely believed your assumptions to be correct after what you believed to be a lot of visual evidence. But the goal of science is to advance knowledge, not assumption. So to have physicists verify information you believed, but never knew, is still quite useful.
insignificant_fish
1 / 5 (6) Nov 08, 2013megmaltese
1.4 / 5 (9) Nov 08, 2013Women do this since ever.
But to be honest, I just began sitting when peeing because of lazyness, because I never even HAD this "problem".
When I pee and standing, I just address the jet to an average angled surface on the impact point.
That cuts off a lot of the inertial energy without producing flying droplets, and nothing ever came out of the toilet.
It astounds me that such a large part of humanity is still peeing straight into the water and whine about this "problem".
Gigel
5 / 5 (2) Nov 08, 2013daqddyo
3.7 / 5 (3) Nov 08, 2013As an avid experimenter, I learned this trick back when I was a kid wearing short pants. The edge of the water in the tank is the place for these "wiz kids" to focus their attention.
TheGhostofOtto1923
1 / 5 (3) Nov 08, 2013