Nodes grouped with regard to geometry and boundaries

Post processing utility for Elmer
Post Reply
Mateusz
Posts: 2
Joined: 13 Jan 2021, 20:50
Antispam: Yes

Nodes grouped with regard to geometry and boundaries

Post by Mateusz »

Hi everyone,

I am looking for a solution that will allow estimating drag (pressure acting on the surface) created by a simulated shape.

Exactly the same as discussed in https://www.youtube.com/watch?v=J944HOj_4b0&t=0s.

However, I cannot find how to group nodes/elements on specific surfaces due to the geometry of the model.

I am using Salome to group geometries in 2D simulation. Elmer sees these groups, however, I cannot extract them to ParaView.

Is it possible in the Elmer?

Thanks,
Mateusz
raback
Site Admin
Posts: 4173
Joined: 22 Aug 2009, 11:57
Antispam: Yes
Location: Espoo, Finland
Contact:

Re: Nodes grouped with regard to geometry and boundaries

Post by raback »

Hi

I suggest you use "Calculate Loads = True" and then appropriate "boundary sum" operator in SaveScalars module. You may need to do this component-wise to "Flow Solution Load i", i=1,2,3. This will get you the most accurate force estimation possible that includes also drag effects.

edit: There seems to be a test case "RotatingBeamFlow" that computes the total force. It uses concept of "Component" which is not so often used. It comes from electromagnetics where it makes sense to define components having lumped features like capacitance etc. However you can also group boundaries of Navier-Stokes solution and have them constitute a "component".

https://github.com/ElmerCSC/elmerfem/tr ... ngBeamFlow

-Peter
Mateusz
Posts: 2
Joined: 13 Jan 2021, 20:50
Antispam: Yes

Re: Nodes grouped with regard to geometry and boundaries

Post by Mateusz »

Yes, it works!
Thanks a lot!
raback
Site Admin
Posts: 4173
Joined: 22 Aug 2009, 11:57
Antispam: Yes
Location: Espoo, Finland
Contact:

Re: Nodes grouped with regard to geometry and boundaries

Post by raback »

Hi Mateusz,

Perhaps you could share the sif for those facing the same challenge in the future.

-Peter
Post Reply