Bubble dynamics reveal how to empty bottles faster

April 07, 2020

WASHINGTON, April 7, 2020 -- Bottle emptying is a phenomenon most of us have observed while pouring a beverage. Researchers from the Indian Institute of Technology Roorkee discovered how to make bottles empty faster, which has wide-ranging implications for many areas beyond the beverage industry.

Bubbles have been studied extensively for centuries, including early efforts by Leonardo da Vinci who famously noted the sinusoidal rise of bubbles within a pool. The growth dynamics of bubbles at the mouth of a bottle depend on the thermophysical properties of the fluid, the bottle geometry and its angle of inclination. These inextricably intertwined parameters have made bottle-emptying dynamics the next frontier for bubble physicists.

In this week's Physics of Fluids, from AIP Publishing, Lokesh Rohilla and Arup Kumar Das explore this bottle-emptying phenomenon from the perspective of bubble dynamics on a commercial bottle by using high-speed photography. Image analysis allowed them to conceptualize various parameters, such as liquid film thickness, bubble aspect ratio, rise velocity and bottle emptying modes.

"Bubble dynamics inside the bottle are too complex to study, so we divided the bubble interfacial growth into different stages to comprehend them," said Rohilla.

It's well known that a bottle's emptying time is faster if you increase its angle of inclination. This increases what's known as bubble pinch off frequency, and the relative increment depends upon the thermophysical properties of the fluid.

"Our experiments suggest there is a critical angle of inclination, after which any further increase in the inclination of the bottle won't lead to further reduction in the bottle emptying time," said Rohilla. "This occurs due to the saturation of the voidage, space occupied by air within liquid surrounding, at the bottle's mouth with the angle of inclination."

Two distinct bottle-emptying modes were identified. In one mode, the discharge rate is increased due to a high frequency pinch off of air bubbles inside the bottle. In the other mode, it is caused by an increase in volume of the pinched-off bubble at a comparatively lower frequency.

"We've also observed an encapsulated bubble while discharging fluid in a vertically upended bottle," Rohilla said. "Encapsulated bubbles have pinch off sites outside the bottle mouth, contrary to intuition. The presence of a violent ejector jet within inviscid fluids, in which liquid becomes thin due to almost no internal friction, and its complete absence within viscous fluids control the periodicity of the bubbles."

This work proves that bottle geometry and thermophysical properties play a role in reducing the time it takes for a bottle empty.

"We can manipulate the bottle discharge pattern by manipulating bottle geometry," said Das. "An intuitive product-specific bottle design will enable better control of its discharge rate."

The beverage industry and chemical plants are among the applications that will benefit from this better understanding of bottle geometry.
The article, "Fluidics in an emptying bottle during breaking and making of interacting interfaces," is authored by Lokesh Rohilla and Arup Kumar Das. It will appear in Physics of Fluids on April 7, 2020 (DOI: 10.1063/5.0002249). After that date, it can be accessed at https://aip.scitation.org/doi/10.1063/5.0002249.


Physics of Fluids is devoted to the publication of original theoretical, computational, and experimental contributions to the dynamics of gases, liquids, and complex or multiphase fluids. See https://aip.scitation.org/journal/phf.

American Institute of Physics

Related Bubbles Articles from Brightsurf:

Work bubbles can help businesses reopen while limiting risk of COVID-19 outbreaks
Creating ''work bubbles'' during the COVID-19 pandemic can help reduce the risk of company-wide outbreaks while helping essential businesses continue to function, as the example of Bombardier Aviation demonstrates in an analysis published in CMAJ (Canadian Medical Association Journal) https://www.cmaj.ca/content/early/2020/09/29/cmaj.201582.

Bouncing bubbles shake up emulsion studies
Collisions of tiny air bubbles with water surfaces can reveal fundamental characteristics of foamy mixtures.

Tiny bubbles make a quantum leap
Researchers at Columbia Engineering and Montana State University have found that placing sufficient strain in a 2D material creates localized states that can yield single-photon emitters.

Soap bubbles pollinated a pear orchard without damaging delicate flowers
Soap bubbles facilitated the pollination of a pear orchard by delivering pollen grains to targeted flowers, demonstrating that this whimsical technique can successfully pollinate fruit-bearing plants.

First optical measurements of Milky Way's Fermi Bubbles probe their origin
Using the Wisconsin H-Alpha Mapper telescope, astronomers have for the first time measured the Fermi Bubbles in the visible light spectrum.

Double bubbles pierce with less trouble
Two microscopic bubbles penetrate soft materials better than one, concludes a new study by engineers at UC Riverside.

Novel tin 'bubbles' spur advances in the development of integrated chips
The use of extreme ultraviolet light sources in making advanced integrated chips has been considered, but their development has been hindered owing to a paucity of efficient laser targets.

Bubbles go with the flow
Scientists at The University of Tokyo developed a new computer simulation model that includes microbubble nucleation to explain the flow slippage of fluids inside pipes.

Physics of giant bubbles bursts secret of fluid mechanics
A study inspired by street performers making gigantic soap bubbles led to a discovery in fluid mechanics: Mixing different molecular sizes of polymers within a solution increases the ability of a thin film to stretch without breaking.

Cosmic bubbles reveal the first stars
Astronomers using the Mayall telescope at Kitt Peak National Observatory, a program of NSF's National Optical-Infrared Astronomy Research Laboratory, have identified several overlapping bubbles of hydrogen gas ionized by the stars in early galaxies, a mere 680 million years after the Big Bang.

Read More: Bubbles News and Bubbles Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.