Don't let the COVID get the better of you 2 (room with two windows)

Let's take a look!

What type of experiment is this?

Experimental procedure and explanation:

• By using cardboard, we develop a model of a room that is 10-cm wide, 10-cm long, and 5-cm high. In addition, a 2-cm wide window was added in the center of each of the front and back walls. A transparent board is attached to the ceiling.
• When air is blown from the front, you can create a breezeway and increase ventilation to a much greater extent than when you only have one window.
• However, near the wall, the flow is weak, creating an area of circulation, called a separation zone, where it is difficult to ventilate.
• Next, when the wind is applied at an angle of 45°, the flow entering from the entrance goes almost straight until it hits the wall, and it changes the direction of the flow taking it to the exit. An air passage is created, thus providing ventilation.
• However, in the corners and blind spots of the flow, there are separation 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 somewhat more of a ventilation effect.
• The key result is that two windows will provide more ventilation than a ( 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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