CFD/FSI with RADIOSS; Material for low Mach Number and Tetra Elements

Matthias Conjaerts_21193
Matthias Conjaerts_21193 New Altair Community Member
edited July 2021 in Community Q&A

A few weeks ago I attended the RADIOSS FSI Training. On one slide there was a nice summary of Materials and their different use cases.

Now I am starting to build my first model and was wondering, which material i should use with the following restrictions:

- mesh with Tetra-Elements

- low mach number ~0.01

 

The final goal is to analyse the FSI of a check valve inside an air intake pipe.

Im happy for every Best Pratice, regarding this kind of analyse.

image

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Answers

  • Mathis
    Mathis
    Altair Employee
    edited July 2021

    Hi Matthias,

    Thank you for the positive feedback about the table.

    Actually the behavior of law151 with tetra elements should be ok, even with low mach number. It is only with hexa elements and low mach number that it is not recommanded to use law151. I will update the table accordingly.

    Regards,

    Mathis.

  • Matthias Conjaerts_21193
    Matthias Conjaerts_21193 New Altair Community Member
    edited July 2021

    Hi Mathis,

    thanks for your response. I will try LAW151 with Tetra-Elements on my model.

    I noticed a comment in the help section of /EBCS/FLUXOUT.

    The comments says:

    1. The FLUXOUT boundary condition is compatible with /MAT/LAW151.
    2. FLUXOUT imposes a zero normal derivative of the fluxes on the elements of the input surface: mass, momentum and energy fluxes.
    3. This will provide a continuity of the numerical solution if the outgoing flow is supersonic. However, this may lead to wave reflection with subsonic flows.

    Is the last comment also only valid for Hexa-Elements?

  • Mathis
    Mathis
    Altair Employee
    edited July 2021

    Hi Matthias,

    Yes it should be. Could you please provide us feadback after testing?

    Thanks a lot !

    Mathis.

  • Matthias Conjaerts_21193
    Matthias Conjaerts_21193 New Altair Community Member
    edited July 2021

    I did some testing.image
    The max. velocity with LAW151 is very low. I defined an inlet velocity of 10 m/s in all simulations. But it seems like this did not really work with LAW151. Maybe there is an error in the input deck. I attached all the files of the 4 runs.

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