Splash-free urinals: Design through physics and differential equations

In a restroom with commercial contemporary models, cardboard rectangles were placed under each.

Maybe of all there was none to fault; it was just the physics of poor design.

This comes close to my hobby science of 20 yrs+! Toilet statistics! What distribution do people follow in choosing doors? Linear (no!), Negative Binomial (I think so, but which parameters? And do the number of stalls matter?), Gaussian? Do cleaners clean all stalls proportionally? Which urinal to choose? Never pick a neighbor? Is there an optimization there? Then the economics part…

Regarding OP. Splash isn’t the only factor in urinals alas. Ease of cleaning and the ability to stop junk. I’ve seen innovative splash less designs in bars. Usually a plastic cup upside down will seriously mess up the flow. People throw paper and gum and cigarettes in them. You need it splash free And robust.

Is it normal not to include the source of the governing equation (the ODE in equation 4)? I could not find any mention of it.

I think it's not a coincidence that they decided to publish on PNAS...

88 points, 105 comments from yesterday:

https://news.ycombinator.com/item?id=43668957