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Subject: Re: FSI/Fluid30 + Solid98 + Damping?
Author: Alessandro Bellina
Date: 2008-10-07 14:23:08

Olaf,
Thank you for your answer. I did manage to get it to work. The issue
was that I wasn't using EMODIF to change the type of the elements in
the vicinity of the fluid/structure interface. I thought that just
using TYPE would do the trick...

Have you used Solid98? If you have, do you get pressure values at
their nodes even though they are structural?

Thanks for the help,

Alessandro


On Oct 7, 2008, at 2:22 AM,
wrote:

> Allessandro,
>
> There is one more thing to do to have the effect of a boundary
> impedance
> to be taken into account. You need to mesh the fluid30 elements in
> contact with your structure having the FSI flag switched on:
> et,'YOURELEMENTTYPE#',fluid30,,0
> All other fluid elements will be meshed w/o the FSI flag
> et,'YOURELEMENTTYPE#',fluid30,,1
> Furthermore (as you did), you need to specify the boundary impedance
> mp,mu,'YOURMATERIAL#','YOURIMPEDANCEVALUE'
> and set the impedance flag by selecting all elements in touch with the
> structure and specifying the surface load
> sf,all,impd,1
>
> It seems to work for me. Hope that helps.
>
> Best regards,
> Olaf
>
>
> German Aerospace Center (DLR)
> Member of the Helmholtz-Association
>
> Institute of Composite Structures and Adaptive Systems
>
> Dr. Olaf Heintze
>
> Braunschweig, Germany
>
>> -----Original Message-----
>> From: xansys-bounces_at_xansys.org [mailto:xansys-bounces_at_xansys.org] On
>> Behalf Of Alessandro Bellina
>> Sent: Tuesday, October 07, 2008 12:11 AM
>> To: xansys_at_xansys.org
>> Subject: [Xansys] FSI/Fluid30 + Solid98 + Damping?
>>
>> Hello,
>> I am under the impression that to accurately model a structure
>> submerged in a fluid, damping needs to be added to the system (i.e.
>> Ansys doesn't automatically take this into account.) Because of this
>> I've added a "mu" parameter to the boundary fluid30 elements
>> (touching
>> the FSI). I've also turned on the IMPD flag for the fluid elements.
>> However, I am not finding this to take any effect. Regardless of the
>> value of "mu", the model is not damping at the fluid-structure
>> boundary. Any of you have dealt with this issue?
>>
>> Thanks,
>>
>> Alessandro
>>
>> Alessandro A. Bellina
>> bellina_at_illinois.edu
>> ---
>> Graduate Student
>> Bioacoustics Research Laboratory
>> Electrical and Computer Engineering
>> ---
>>
>>
>>
>>
>>
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>> ^----------------------------------------------------
> ^----------------------------------------------------
> | XANSYS web - www.xansys.org |
> | XANSYS blog - xansys.blogspot.com |
> | The Online Community for users |
> | of ANSYS, Inc. Software |
> | Hosted by PADT - www.padtinc.com |
> ^----------------------------------------------------

Alessandro A. Bellina
bellina_at_illinois.edu
---
Graduate Student
Bioacoustics Research Laboratory
Electrical and Computer Engineering
---





Posts possibly associated with message #95372AuthorDateScore
95365FSI/Fluid30 + Solid98 + Damping?Alessandro Bellina 2008/10/06 
95366Re: FSI/Fluid30 + Solid98 + Damping?Olaf Heintze2008/10/0710
95372Re: FSI/Fluid30 + Solid98 + Damping?Alessandro Bellina 2008/10/07 
95373Re: FSI/Fluid30 + Solid98 + Damping?Olaf Heintze2008/10/07