Physicists learned how to pour liquid out of a bottle as quickly as possible. Researchers at the Indian Institute of Technology have identified how to control the formation of bubbles that form when water and oil are poured from a bottle. The work was published in the journal Physics of Fluids.
Physicists have been working for several decades to create the optimal form of packaging for liquids, which allows you to quickly pour water, oil, and squeeze the last drops of toothpaste or ketchup.
Most often, scientists are creating a special coating, which, when applied to the walls of the vessel, allows you to repel liquid – and, thanks to this, quickly empty the bottle.
In a new study, scientists approached the problem from the other side – they investigated the mechanism of the formation of air bubbles that prevent the rapid pouring of liquid from the bottle and found a way to control it.
The work showed that active bubble formation occurs when the bottle is tilted to an angle of 20°. After this mark, with a further slope, the rate of bubble formation and fluid flow remained practically unchanged.
“Our experiment showed that for bottles of any type there is a critical angle of inclination, upon reaching which the liquid flows out of the bottle as quickly as possible. This parameter is associated with the peculiarities of how voids and bubbles are formed at the neck of the bottle. Our study will allow you to choose the shape of the neck of the bottle, thanks to which water, oil or alcohol will flow as quickly as possible”.
Lokesh Rohilla, lead author of the study