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-   -   FSI help Fluent-Structural Analysis (https://www.cfd-online.com/Forums/fluent/85809-fsi-help-fluent-structural-analysis.html)

nikupasca March 7, 2011 15:49

FSI help Fluent-Structural Analysis
 
Please help me. I am new in FSI simulation, I'm PhD student and I want to simulate structural behavior of hydraulic blade using fluent and structural analysis. Mentioned I performed the fluent analysis using Gambit for design and fluent for analyse, I want to know some steps which I can follow for a structural analyse. How can use the same mesh for solid blade , from fluent for structural analyse?I need this for 100% mach imported pressure in structural analyse. How I can work in Ansys workbench???
Please help me.
Thank you.

Sony March 10, 2011 00:15

Hi ,
is your FSI 1-way or 2-way?
If it is 1-way I believe you can use ansys structural.
But for 2-way fluent cannot be used. For this you need a third party software like MpCCI .

However you can use CFX since CFX has 2-way FSI with Ansys structural.

Hope this information helps.

Cheers,
Sony

nikupasca March 10, 2011 01:41

Thanks for your replay. Is FSI 1 way, and I have all the analyses in fluent, for a hydraulic blade and now I want a structural analyse only for blade. I don't know how is made? because if I dont have 100% mach with the pressure imported in structural analyse, the analyse is not ok, so I need the same mesh like in fluent for bladesurf. Can you help me?

Sony March 10, 2011 17:29

Is your simulation for a steady or transient?

If you are doing transient then, I would imagine 2-Way FSI is the right approach since hydraulic blade is surrounded by fluid and fluid exerting different pressure across different sections, which results in different deflections of the solid across these sections and the subsequent affect on the flow of these deflections.

If it is a steady simulation, and you have the pressure profile across the blade and you are wanting to do only structural analysis based on these pressure profiles, then you will have map the pressure profile in fluent on the Ansys(or any structural solver) file.
It is there in the file pull down menu, FSI mapping -> surface map.
You can select Ansys(APDL) file and export the profile on the blade surface. I don't think you need the same fluent mesh, you can have a structural mesh of ansys (I believe it will interpolate the values from fluid mesh to structural mesh at the interface) , but the geometry and the orientation has to be identical.

I haven't tried this approach personally but I think there might be tutorials available.
Hope this helps.

Cheers,
Sony

alialibas October 24, 2011 10:27

Hi Sony,

You mention that in Fluent, there is FSI Mappig tab, for temperature, pressure, force, etc. I am trying to use this method but for structural loads, I couldnt find the proper way to do that. Especially in 2D analysis, I need to use FSI Mapping Surface. I prepare an *.cdb input file in ANSYS Classic (Element type is Surf 153) But the problem I have is cannot map "pressure" onto where I'd like to map (obviously, it is a line, with surf153 element) But I can map "Force" onto that line without any changes in that *.cdb input file. The problem is What does Fluent do while mapping "Force" or why cannot Fluent map "Pressure" onto that line?? I cannot find a good precedure for this method.

I tried same method for 3D structural analysis. Its mapping is more reliable according to results. I want to map "pressure" values in a 2D analysis. Do you have any idea?

Thank you..

Ali

Saima June 18, 2012 14:12

Hello Guys,

I am doing stress analysis for a compressor blade.

I have done flow analysis in CFX and have result file. Now wants to do stress analysis in Ansys classic. How can i import pressure loading through a CGX result file?

I know it is easy to do i workbench but dur to some conditions i have to import in ansys classic. Pls let me know how can it possible?

Regards,



Quote:

Originally Posted by alialibas (Post 329196)
Hi Sony,

You mention that in Fluent, there is FSI Mappig tab, for temperature, pressure, force, etc. I am trying to use this method but for structural loads, I couldnt find the proper way to do that. Especially in 2D analysis, I need to use FSI Mapping Surface. I prepare an *.cdb input file in ANSYS Classic (Element type is Surf 153) But the problem I have is cannot map "pressure" onto where I'd like to map (obviously, it is a line, with surf153 element) But I can map "Force" onto that line without any changes in that *.cdb input file. The problem is What does Fluent do while mapping "Force" or why cannot Fluent map "Pressure" onto that line?? I cannot find a good precedure for this method.

I tried same method for 3D structural analysis. Its mapping is more reliable according to results. I want to map "pressure" values in a 2D analysis. Do you have any idea?

Thank you..

Ali


zakir hussain July 4, 2012 10:58

Hi
I want to do a simulation on 1-way FSI from fluent to Mechanical.I think I need use the FSI mapping(-> surface map) function.But then I have to input a Ansys(APDL) file(.cdb file).what confused me is where is this .cdb file from.I already have finished a steady simulation and have the result(.data file) file.What I need to read into Mechanical solver is only the pressure profiles.

Thank you very much!

zakir

nauman55 July 22, 2012 08:56

Use FSI custom systems
 
you can use fsi from custom systems available in work bench. with this you can import the aerodynamic pressure loads from your fluent simulation.
regards

zakir hussain July 26, 2012 08:41

Quote:

you can use fsi from custom systems available in work bench.
thank you for your suggestion.I am new to workbench.
Quote:

with this you can import the aerodynamic pressure loads from your fluent simulation.
regards
Do you mean that If I already have .cas and .dat files I can use them directly without reinput geometry or mesh?

regards!
zakir

nauman55 July 26, 2012 10:24

Fsi
 
Do you mean that If I already have .cas and .dat files I can use them directly without reinput geometry or mesh?

no sir it is a integrated stuff in which first your will carry out the cfd for which u will need geometry and mesh both. these options are available in schematics. after running your cfd simulation you will go to ansys static structural carry out meshing again and then by import loads you can import pressures directly from cfd results.
do let me know if problem still persists.
my email is naumaneshanhashmi@gmail.com

nauman55 July 26, 2012 10:27

ansys FSI component system with cfx
 
Quote:

Originally Posted by Saima (Post 367057)
Hello Guys,

I am doing stress analysis for a compressor blade.

I have done flow analysis in CFX and have result file. Now wants to do stress analysis in Ansys classic. How can i import pressure loading through a CGX result file?

I know it is easy to do i workbench but dur to some conditions i have to import in ansys classic. Pls let me know how can it possible?

Regards,

maam you can do it with fsi custom system for cfx. in which you can import loads and carry out static structural analysis from it. if any query still persists feel free to contact at naumaneshanhashmi@gmail.com

Silver Silhouette April 11, 2015 05:00

Fluent Static Structural Analysis
 
2 Attachment(s)
i have got a small doubt in FSI analysis..i made my wing and put a rectangular domain region over it..i ran the flow analysis over it and found out pressure distribution over the wing.this pressure i imported to static structural analysis.i then clicked the root of the wing as my fixed support and ran deformation analysis. i think i got the results but the problem is i cant view the wing alone.. it is coming along with the rectangular boundary region.
how can i view the deformation on the wing alone?
i ll attach some files for reference

thanx in advance:):):)

ujwal rajan September 2, 2017 05:43

2 way FSI help
 
Hello guys,

Hope you are all doing well. (This is my first time performing FSI analyses)

I want to conduct a 2 way FSI on an airfoil {2D case, using FLUENT, transient flow}. I do have a UDF and a journal file. When the UDF is run in MATLAB, it gives the time, pitch response, plunge response, lift force and pitching moment of the airfoil.
When i use the journal file in FLUENT, it successfully runs the aerodynamic analyses.

Next,
When i try using the system coupling for 2 way FSI in workbench after making use of the journal file, it tells me that FLUENT does not support 2D case for system coupling. (which i am well aware of now)

My doubt is that:
1) Can i perform 2 way FSI in static structural module in workbench?
2) If 2 way FSI cannot be performed using static structural module, how do i go about importing/performing 2 way FSI in transient structural module?
3) Is there a way of using the data (time, pitch response, plunge response, lift force and pitching moment of the airfoil) as the pressure loads over the airfoil?

Thank you,
Any help is massively appreciated.

ujwal rajan September 2, 2017 06:00

Hey Ali Bas,

The thing is that FLUENT cannot map volume and surface data for 2D cases. I'm going through the same problem as you are right now.
Details are given in the following link:
https://www.sharcnet.ca/Software/Ans...fsi_using.html


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