Learning Forum

[crumberg]

I have been attempting to model an enclosed incompressible viscoelastic fluid using the HSFLD242 element type in Workbench Mechanical 2021R2. So far, I have been unable to create the HSFLD242 elements. Referencing the following tutorial, I inserted an APDL command snippet into my Mechanical project tree: Contained Fluid in FEA Model with Hydrostatic Elements | SimuTech (simutechgroup.com)

[peteroznewman]

See if some of the discussions on this site are helpful.
https://www.google.com/search?q=site%3Aforum.ansys.com+HSFLD&oq=site%3Aforum.ansys.com+HSFLD

[crumberg]

Thanks for the response! I had taken a look at these before posting. Many of the questions are similar to mine, but they don't seem to get answers or at least not answers which resolve the problem that I am having.
I still have been unsuccessful in all my attempts to create a HSFLD242 element. One of the many things I have tried is to use the /clear command at the top of my APDL snippet. However, if I include it then I can no longer use the cmsel command because my named selection has been cleared and it is necessary to select all interior surface nodes to create the HSFLD242 elements. However, if I do not use the /clear command, then the part retains a mesh with Tet10 elements and therefore cannot create the HSFLD242 elements.

[Ashish Khemka]

Please see if the following link helps:
HSFLD241/242: Modeling Enclosed Liquids ÔÇô PADT, Inc. ÔÇô The Blog (padtinc.com)
Regards Ashish Khemka

[crumberg]

Hello akhemka. Thanks for the response. The link you shared is one of the two tutorials that I was able to find on the subject. Unfortunately, it shows a 2D example (HSFLD241) rather than a 3D example (HSFLD242) and more importantly, it bypasses Workbench. The entire process starting with creating the geometry is written into the Macro. This allows the user to mesh only certain parts at a time, thus sidestepping the placement issue in Workbench Mechanical. I ultimately need to apply my method to a fairly complex model that is already built in Workbench. (The fluid sack project is just for me to learn how to use HSLFD242 so that I can apply it to the more complex model.) It will be a very involved process for me to attempt to script everything from the ground up as shown in the tutorial since I do not have a background working with APDL script. (I am looking into using pyAnsys just in case, but it's still a new API for me to learn which may or may not support the functionality I need.) Do you know of any resources that would show me how to correctly use HSFLD 242 elements in Workbench?

[Erik Kostson]

Hi
There is an extension in the ansys app store which is called hydrostatic fluid and exposes the HSFLD elements in workbench mechanical - this is not free for all to download though (might need a subscription or a customer portal account or that one has support service in place for their licence, but not sure exactly).

All the best

Erik

[crumberg]

Thank you so much! I did not know about this extension, but it sounds like a great option. Unfortunately, available versions only go up through Workbench 2020 and I have been using Workbench 2021. I will try recreating a simple project in an older ANSYS version and see how it goes.

[crumberg]

Thanks for the ideas for addressing this issue. The solution to the problem turned out to be very simple if somewhat esoteric. It turns out that the fluid cannot be included as a geometric component but must be left as a hollow cavity in the model. The APDL command snippet shown in the Simutech tutorial then worked correctly to generate HSFLD242 elements when the command was placed at the end of the project tree (below analysis settings).