Air Flow Behind a Board

Let's take a look!

Watch the video on YouTube.

What type of experiment is this?

Experimental procedure and explanation:

• When the board is placed in the middle of the airflow, “separation” occurs. A vortex is created behind the board, and a circulating airflow is formed.
• Airflow cannot bend suddenly and cannot go around the rear of an object such as a board, thus creating a vortex.
• When a board is placed in the path of airflow from a fan and a bag is subsequently placed behind the board, the bag rides on the circulating airflow and is drawn towards the board. If this is skillfully performed, you can also see how the airflow is circulating.
• This is the same principle that affected the flame of the candle to bend forward in the “Candle Behind a Flat Board” experiment.

[Keywords]	separation, air resistance
[Related items]	Quickly Rapidly Dropping Light Objects, Candle Behind a Flat Board Plate
[Reference]	The Japan Society of Mechanical Engineers, “The Wonders of Flow [Nagare no Fushigi],” Kodansha Blue Backs, P136–139. Ryozo Ishiwata, “Illustrated Fluid Dynamics Trivia [Zukai Zatsugaku Ryutai Rikigaku],” Natsume Publishing, P66–69.