Learning Forum

[伊藤颯葵]

Hello.

I want to analyze the ventilation of a room.

Imagine a room like the one shown.

Open windows and doors to move the ventilation fan.

Please tell me the setting method.

[Karthik Remella]

Hello I'm not sure if I completely understand your question. Are you modeling the effect of open doors and windows on the ventilation fan (if the fan would spin or not)? Or is the ventilation fan driving some flow from the open doors or windows? Please clarify your modeling objectives.
Thank you.
Karthik

[伊藤颯葵]

.
Thank you for your reply.
The wind speed of the ventilation fan is known.
At that wind speed, air is blown out of the room from the ventilation fan.
Then, I think that air will come in through the open windows and doors.
I want to set the air that was originally in the room and the air that comes in later.
I would like to know how the air is replaced and how long it takes to ventilate.
It does not take into account temperature, wind, or movement of people.

[Rob]

OK, so assuming there is no wind use a negative velocity on the extract fans and pressure boundaries on the windows & doors.
Re the ventilation rates, look up "mean age of air" to avoid needing to run transient tracers etc.

[伊藤颯葵]

.
Thank you for your reply.
How can I find out the "mean age of air"?
I still don't know how to use ANSYS, so please tell me in detail how to set up and mesh.

[Rob]

Re software usage, please do the tutorials to become familiar with the tools and use those skills to set up your model. You'll find these in the Help system.
For mean age of air, I find Google to be a very useful tool. In this case it picks up an article from our Australian partner LEAP, https://www.computationalfluiddynamics.com.au/tips-tricks-calculating-mean-age-of-air-with-cfd/