Learning Forum

[jstevens]

I am trying to simulate a crawlspace ventilation system under an apartment building.  I have one exhaust fan that is exhausting 300 cfm from the crawl space through intake openings around the perimeter of the crawlspace.  My intent is to set the velocity of the exhaust fan outlet opening to 3.67 fps (300 cfm through a 14" x 14" opening) and have the inlet openings (7 inlet openings)  respond accordingly so that I can see if the circulation throughout the crawlspace is adequate.  When I set it up this way, I get no airflow at all.  Any advice is greatly appreciated.  the model is attached.

🛈 This post originally contained file attachments which have been removed in compliance with the updated Ansys Learning Forum Terms & Conditions

[Subashni Ravichandran]

Hi  jimmystevens When I tried to run your model I'm getting airflow as expected. Refer to the image attached. I assume the problem is with your GPU. I run this model on a computer with Quadro P5000 16Gb graphics card. Also, as you have the values to the mass flow rate, you can directly specify the mass flow rate in Ansys Discovery Live 19.1 (shown in image). Although, this feature is not available in 19.0. I would highly recommend you to install 19.1 and enjoy a better version of Discovery Live,

[devicechief]

Subashni I tried the same thing, and got the same result (it worked for me as well). I'm using a Maxwell-based NVIDIA GPU.

[justin.hendrickson]

Subashni Yes, the 19.1 version is required to use velocity conditions only. I also recommend leaving the inlets as pressure conditions. I have attached a model where this is the case.

🛈 This post originally contained file attachments which have been removed in compliance with the updated Ansys Learning Forum Terms & Conditions

[hashan.mendis]

Looks like there isn't an outlet condition. Try adding pressure as 0 on a face to model an outlet.