Circle and Square 3

Let's take a look!

Watch the video on YouTube.

What kind of experiment is this?

Experimental procedure and explanation:

• Let us observe a flow around a cylinder and a rectangular box.
• We attach plastic strings to a blower so that the flow direction becomes visible.
• You can see that with a cylinder, the flow follows the round surface, while with a rectangular box the flow follows the flat face and then it flows away. As a result, the box receives a force that is in the opposite direction to the direction in which the flow is bent.

[Keywords]	separation, Coanda effect, momentum theory
[Related items]	Circle and Square 1, Circle and Square 2
[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