Learning Forum

[jstevens]

Does anyone have any experience with simulating HVAC in a room? I am new to discovery live and trying to create such a simulation.  I can set up the ductwork and airflows, but when I build a room around the ductwork, Discovery Live doesnt let me access the ductwork within the room.  I can only select the room boundary surfaces.  Any help will be greatly appreciated.

[jstevens]

I have modified this model to create a better solid, but the airflow seems to be ignoring my ductwork in side the model.  the airflow just seems to enter the room through the wall and ignore the ductwork and its openings after that.   I have uploaded the model if anyone cares to look at it.

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[Brian Bueno]

jimmystevens The model you uploaded has quite a few geometry problems.  I was able to resolve these by cleaning up the duct.  In particular, you should consider recreating the holes, as these have a lot of faceting and bad edges. The duct walls are also very thin, so you will most likely need to increase the fidelity of the analysis in order to get better results.  Thickening the walls also improve the results substantially. I have uploaded the fixed model below.  I still recommend adding some thickness to the ducts.

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

[jstevens]

BBueno_ANSYS 

Thank you for looking at this!  I created the model in Sketchup and used a plugin called "Solid Inspector" to make sure that I had a water tight enclosure, so Im baffled that Ansys translated it differently.  Would I be able to clean the model up using "SpaceClaim" if I knew how to  use it better?  Thanks in advance.

[jstevens]

BBueno_ANSYS 

 

I just downloaded the model and opened it in Ansys Live.  It appears that the airflow still does not flow through the ductwork.  It simply blows freely into the space, ignoring the ductwork.  

[Brian Bueno]

jimmystevens The walls on the duct in your model may just be too thin, or the fidelity setting is too low. I created a simplified example with 4 mm thick duct walls and the results looked much better.  The image below is after a simulated time of 0.3 seconds.

[Brian Bueno]

jimmystevens I've tried several different models similar to your design, and in each case the limiting factor is the thickness of the duct walls. Discovery Live is intended to provide real time feedback that adapts instantly to changes in the design geometry.  The trade off is that the fidelity of the results must be lower than a typical FEA tool. I would recommend using Discovery AIM for your analysis.  If you are looking for general results without a very high level of accuracy, you could thicken the walls of the duct and run the analysis with that updated geometry in Discovery Live. With thicker walls, your results would look something like the image below:  

[jstevens]

Ok, I can work with this.  Thank you for taking the time to help this beginner understand.