A Single Plastic Bottle

Let's take a look!

Watch the video on YouTube.

What kind of experiment is this?

Experimental procedure and explanation:

• Place a plastic bottle on its end and blow air from a dryer pointing to a location slightly off center. (A guide is also used so that the bottle will not move back.)
• The bottle is drawn to the air flow.
• With a curved surface, the flow is bent along the bottle surface (Coanda effect). At this time, the air is drawn to the bottle and, as a reaction, the bottle is drawn to the flow.

[Note]	Often, this is explained as "The flow is faster where the dryer air is blowing, and the pressure becomes lower according to Bernoulli's theorem, and the surrounding objects get drawn." This is incorrect. The pressure where dryer air is flowing is about atmospheric pressure (See references for detail).
[Keywords]	Coanda effect, momentum theory
[Related items]	Two Plastic Bottles (Note the difference in the principles behind them)
[Reference]	“Illustrated Fluid Dynamics Trivia,” by Ryozo Ishiwata, Natsume Publishing, pp. 214-215 and 206-209 “The Wonders of Flow,” Japan Society of Mechanical Engineering, Koudansha Blue Backs, pp. 140-143