Head-Shaking Research — Ejecting Water From the Ear Canals

Ejecting water from a person’s ear canals is potentially thrilling, for fluid dynamicists and perhaps for the person. New research on the how and why will be presented at a meeting in November:

Acceleration induced water removal from ear canals,” Hosung Kang, Katelee Averett, and Sunghwan Jung, paper (Abstract D5.00007) to be presented at the 70th Annual Meeting of the APS Division of Fluid Dynamics, November 19–21, 2017; Denver, Colorado. The researchers, at Virginia Tech, report:

“Children and adults commonly experience having water trapped in the ear canals after swimming. To remove the water, individuals will shake their head sideways. Since a child’s ear canal has a smaller diameter, it requires more acceleration of the head to remove the trapped water.

In this study, we theoretically and experimentally investigated the acceleration required to break the surface meniscus of the water in artificial ear canals and hydrophobic-coated glass tubes. In experiments, ear canal models were 3D-printed from a CT-scanned human head. Also, glass tubes were coated with silane to match the hydrophobicity in ear canals. Then, using a linear stage, we measured the acceleration values required to forcefully eject the water from the artificial ear canals and glass tubes.”

The lab has also done research on how dogs drink, how cats drink, how diving birds enter the water, how raindrops hit tree leaves, what happens when wet hands clap, and other not-at-all-simple simple-seeming questions.

(Thanks to Nicole Sharp for bringing this to our attention.)