Don't let the COVID get the better of you 3 (two windows on alternate sides)

Let's take a look!

What type of experiment is this?

Experimental procedure and explanation:

• By using cardboard, make a model of a room 10-cm wide, 10-cm long, and 5-cm high. In addition, 2-cm wide windows were placed on the front and back walls, respectively, at opposite sides of the room. A transparent board is attached to the ceiling.
• When wind is applied from the front, the flow entering from the entrance travels straight, hits the wall, changes direction, and it then heads for the exit. The ventilation is much greater than with a single window due to the creation of a breezeway.
• However, in blind spots, the flow becomes weak, creating a separation zone that circulates, making it difficult to ventilate.
• Next, when the wind is applied at a 45° angle, the flow entering from the inlet goes almost straight, and it then changes direction and goes to the exit. An air passage is created, thus providing ventilation.
• However, in the corners and blind spots of the flow, there are detached zones, making it difficult for ventilation to occur.
• In a real room, the air inside is stirred up by people around, fluctuating winds, and the mixing and diffusion of flows, and thus, even areas of weak flow have a slightly greater ventilation effect.
• The key result is that two windows will result in a better ventilated room than a room with one window ( Room with one window ).
• This experimental video was produced with the support of JSPS Grant-in-Aid for Scientific Research 18K03956.

[Keywords]	Ventilation, separation
[Related items]	Don't let COVID get the better of you 1 (room with one window)
[Reference]	Ryozo Ishiwata and Mitsumasa Nemoto, "The Wondeｒ of Flow" Kodansha Blue Backs, p. 152. Ryozo Ishiwata, "Illustrated Fluid Dynamics Trivia", Natsume Publishing, P68-69.

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