A "low angle of attack" and standing as close as possible to the urinal will result in the least splashback, physicists find.
Urinal splashback. It’s a problem that has plagued men (and their pants) for decades. Now, as the BBC reports, two intrepid American physicists are out to solve this embarrassing issue once and for all.
Professor Tadd Truscott and Randy Hurd, of Utah’s Brigham Young University, have been hard at work researching why and how urine ricochets off lavatories, and on November 24th, the duo will reveal their findings to members of the American Physical Society in a presentation entitled Urinal Dynamics.
Truscott and Hurd understand their work might elicit some snickers, but the effort they’ve put into discovering the secrets of splashback is no joke. The researchers started by building a specialized hose to simulate the pressure and flow rate of a healthy urinating male, even designing two different artificial urethras. Then, they used high speed photography and image processing to study such essential topics as “the effects of stream breakup,” how the “surface impact angle” effects “lateral and vertical droplet ejection distances,” and “the effects of velocity and [toilet water] depth on droplet ejection distances.”
The results won’t surprise most men, but they do confirm conventional wisdom. According to Truscott and Hurd, who jokingly refer to themselves as the ‘wizz kids’ and their laboratory as the “Splash Lab”, the key to a splashless pee is a low “angle of attack.” Urinating against porcelain at a 90-degree angle will cause a mess, but aiming your stream almost parallel to the urinal’s surface will nearly eliminate splashes.
Another trick is to get as close as possible to the urinal’s wall. “The male urine stream breaks up about 6-7 inches outside the urethra exit,” Hurd explained to the BBC. “These droplets are the perpetrators of the splash formation on your khaki pants.” Narrowing the distance between where your stream starts and where it hits the porcelain will mean a smoother flow, and less urine ending up on your clothes.
The more you know!
[youtube=http://www.youtube.com/watch?v=UgOx7zPtsaM&w=560&h=315]