The hydrodynamic and acoustic response of the water-filled Tibetan bowl 3 being rubbed with a mallet.
Researchers have been investigating the connection between fifth century Himalayan instruments used in religious ceremonies and modern physics.
In a study published in IOP Publishing's journal Nonlinearity, researchers have captured high speed images of the dynamics of fluid-filled Tibetan bowls and shown how droplets are propelled from the water's surface as the bowls are excited.
Read the study: http://iopscience.org/non/24/8/R01
Watch related videos: http://iopscience.iop.org/0951-7715/24/8/R01/media
An experimental investigation of the fluid dynamics of Tibetan singing bowls has showed their acoustic behavior is similar to wine glasses, and can even cause water droplets to levitate.
The bowls originate from fifth century rituals in the Tibetan Himalayas, and are typically made from a bronze alloy. They produce a rich sound or song when the sides and rim are struck or rubbed with a mallet.
Two scientists filled the bowls with water and filmed the vibrational patterns that arise. The high-speed camera showed how surface waves formed, creating water droplets that break away from, and bounce on the fluid surface.
These edge-induced Faraday waves or ripples form on liquids inside a vibrating receptacle, and the surface becomes unstable once the vibration frequency goes above a critical value, generating droplets via surface fracture.
“Our study indicates that drops may be levitated on the fluid surface, induced to bounce on or skip across the vibrating fluid surface,” wrote the authors in the study abstract.
The study allowed the researchers to understand how a liquid interacts with solid materials, which is useful in engineering, for example the wind-loading of bridges.
"Although our system represents an example of fluid-solid interactions, it was motivated more by curiosity than engineering applications,” said senior author John Bush at the Massachusetts Institute of Technology in a press release.
"We are satisfied with the results of our investigation, which we feel has elucidated the basic physics of the system. Nevertheless, one might find further surprises by changing the bowl or fluid properties."
These findings could have applications for droplet generation in fuel injectors and perfume sprays, and were published in IOP Publishing's journal Nonlinearity on July 1.