BYU engineers study male urine 'splashback'
It may not create world peace, but it could make the bathroom a kinder, gentler or at least cleaner place.
"Most men, at least once in life, they're wearing the right fabric or they need to use the bathroom real fast and they realize they just speckled themselves," said Randy Hurd, a graduate student in mechanical engineering at Brigham Young University.
Hurd, along with assistant professor Tadd Truscott, are searching for a solution to the age-old but seldom-discussed problem of male urine "splashback."
"We can get to the freaking moon but we can't invent a bowl that won't splash back on me?" he said.
Hurd and Truscott study the "physical mechanisms of fluid behaviors," as they put it on their Splash Lab website Â such as how torpedo shapes enter the water compared to spherical shapes, or how balls skip over the surface. Their work is funded primarily by the Office of Naval Research and the National Science Foundation, though they've spent only a nominal amount of their own money on this study.
In August, they turned that knowledge to the splashback problem. They built a rig to simulate the pressure and flow rate of a healthy male, then used high-speed cameras and backlighting to record droplet creation and dissemination.
"The urine stream breaks up into droplets before it hits, unless you're very close to it," Hurd said. So while most men stand about 10 inches back from the bowl, reducing that distance to five inches can significantly reduce splashing by catching the stream before it breaks up.
Angle is another major factor. Basically, perpendicular is bad. The smaller the angle, the gentler the stream, an effect Hurd likens to pouring a soda into a glass.
"If you pour your soda just into the bottom of the glass â¦ it foams like crazy," he said. "If you tilt it sideways, and pour along the glass at a smaller angle, it doesn't fizz as much."
And though aiming for water in the toilet bowl or urinal might seem like a better option, it only makes things worse.
"You'd think that water would kind of soften the blow, and maybe if it were vertical that would be great," he said. Flushing before peeing doesn't help. "Anytime you throw something into the water it's going to splash."
Hurd and Truscott will present their findings thus far at the American Physical Society's annual meeting in Pittsburgh later this month.
Of course, there is one nearly foolproof way to contain splashback: Sitting.
It's not exactly a popular option, but Hurd and Truscott are hoping to change some perceptions. They're creating a poster for the meeting seeking to re-brand the German word sitzpinkler, a derogatory term for male sitters that also means "pansy" or "wuss," Hurd said.
"If you stand up, you're five times further from the water it's almost impossible not to splash," he said. "You may be made fun of, but you're probably better in the long run. Your wife will probably be happier."