Airplane toilets are known for massive suction and loud flushes.
Those loud flushes are scary for some children.
Now, researchers at Brigham Young University say they've found a way to make those noisy lavatories much less terrifying.
BYU researcher and grad student Michael Rose said:
It’s a great mix between physics and engineering.The toilet is much quieter and now kids won’t think they’re going to get sucked out.
It took two years of trial and error, and thousands of flushes, but a team at BYU says they've invented a vacuum-assisted toilet which is about half as loud as current commodes.
Kent Gee, a physics professor at BYU spoke about the breakthrough:
People have told us they don’t want their kids to be scared to use the bathroom on a flight. So, we’ve used good physics to solve the problem.
Why are current airplane toilets so loud?
"That’s because getting airplane toilets to flush with very little water requires a partial vacuum, which at 38,000 feet, pulls air at nearly half the speed of sound," Media Relations Manager Todd Hollingshead said in a news release. "According to research done in Gee and Scott Sommerfeldt’s [BYU] lab, an air-water mix in vacuum-assisted toilets travels more than 300 miles per hour. When things move at that speed, any disturbance at all to the flow — like the bend of a pipe or a valve — generates significant noise."
Newer airplanes are much quieter inside, which means toilet flushes can reverberate throughout the cabin.
That can interrupt sleeping passengers on longer flights.
“Airline companies have always had standards for the toilet noise, but they’ve never met those and there has never been much pressure to do so,” BYU researcher Scott Sommerfeldt said. “Now with the reduced cabin sound levels, the sound of the toilet flushing is more noticeable and customers are pushing back.”
According to BYU, here's how the research team solved the problem:
The BYU team focused on three valve conditions during the flush cycle: the initial noise level peak associated with the flush valve opening, an intermediate noise level plateau associated with the valve being fully opened and the final noise level peak associated with the flush valve closing. The researchers added additional piping to increase the distance between the toilet bowl and the flush valve and made the pipe attachment at the bowl more of a gradual bend as opposed to a sharp 90-degree angle. Tests of the new contraption show aeroacoustically-generated noise dropped up to 16 decibels during the flush valve opening and about 5 to 10 decibels when the valve is fully opened.
Current airplane toilets will not need to be replaced, the invention works with existing airplane toilets.
"Only the elbow need be removed during a retrofit, while the valve and the bowl stay where they are," Hollingshead said.
The research team has already filed three patents on the new technology and are working to bring it to market.