Wet dogs and other wet ******* shake their bodies in such a precise, effective manner that washing machine designers are taking notice, according to a new study that is the first to explain the physics of ****** self-drying.
In addition to better washing machines, the findings could lead to improvements to dryers, painting devices, spin coaters and other machines.
"It's surprising, but we still do not understand why washing machines work so well," co-author David Hu said. "The equations that govern the fluid motion inside them are too complicated to solve. In this research, we decided to look to nature to ask the question: 'How do we dry clothes effectively and efficiently?'"
To find the answer, Hu and his colleagues used high-speed videography along with X-ray cinematography to see, in detail, what happens both internally and externally as a furry mammal shakes itself dry.
The scientists determined that shaking begins at the head area, which provides a solid point for the energy wave to propagate down the ******'s body. The head can also twist more, resulting in higher amplitude waves.
Once that process starts, "The ******'s head, body and skin all move during a shake," project leader Andrew Dickerson, a researcher in the School of Mechanical Engineering at the Georgia Institute of Technology, told Discovery News.
"The body, though it shakes at the same frequency of the skin, cannot rotate as far," he added. "The skin effectively twists around the body, traveling faster than the body and head can move."
Very furry ******* tend to have especially loose skin, which whips around as the ****** changes direction, increasing the acceleration. Dickerson said it's comparable to someone cracking a whip.
He and his team discovered that ******* with smaller bodies must shake more rapidly than larger *******. These tinier mammals can experience up to 20 g's of acceleration. The chosen frequency of ******* might even be unconsciously determined, based on nerve and muscle dynamics.
