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Harendra February 5, 2005 02:53

Fluid Structure Interaction (FSI)
Dear Experienced users,

What additional software are required to simulate Fluid Structure Interaction? For example, if I want to simulate flow induced vibration of tubes, what is required in addition to Star-Cd? I heard that future version of ANSYS 10 and CFX 5.8 are going to offer this facility. What are the courterparts here in STAR-CD?



F.K. February 5, 2005 04:44

Re: Fluid Structure Interaction (FSI)
I think older versions of Ansys (7?) can be coupled with Easy FSI directly. Another possibility is to use MPCCI Interface from Fraunhofer Institute which becomes more and more the industrial standard for code coupling.As far as I know STAR-CD can be coupled with ABAQUS and PERMANS but you have to buy the license from F.I. So I wonder myself why STAR-CD has no partner from FEM. At the moment the following patnerships between CFD and FEM codes are available without paying for the additional license.

ANSYS 9.0 and CFX 5.7.1 FLUENT 6.2 and ABAQUS 6.5

Harendra February 5, 2005 06:21

Re: Fluid Structure Interaction (FSI)
Many Thanks Mr. F.K for holding same opinion with me and also for providing valuable information.

steve February 6, 2005 22:16

Re: Fluid Structure Interaction (FSI)
This is not true. If you buy Ansys you most definitely do not get CFX for free nor is the reverse true. We happen to have Ansys licenses here (as well as STAR-CD) and I can guarentee you that we can't run CFX. You also do not get Abaqus for free either by buying Fluent. They may have interfaces that are free but you have to buy licenses for each program separately. STAR has been successfully coupled with ANSYS and other FEM programs for FSI.

Harendra February 6, 2005 23:30

Re: Fluid Structure Interaction (FSI)
Mr. Steve,

So according to your opinion, what are the exact requirement for simulating FSI using STAR-CD, or CFX or FLUENT? We have Abaqus 5, Ansys 8, CFX-5.6 and 5.7, Fluent 6.1.22. Would you please specify the versions and additional interfaces for FSI?

Thanks and regards.


F.K. February 7, 2005 03:52

Re: Fluid Structure Interaction (FSI)
I'am not sure if you have read the threads before. Who told you that a CFX or ABAQUS license is for free when you are using Ansys????????????

Once again: If you are a custumer of FLUENT INC and ABAQUS INC. and you have both programs in your company the license for coupling is included and nothing else is mentioned before!!!!!

steve February 7, 2005 16:22

Re: Fluid Structure Interaction (FSI)
This is what you said previously: "At the moment the following patnerships between CFD and FEM codes are available without paying for the additional license. ANSYS 9.0 and CFX 5.7.1 FLUENT 6.2 and ABAQUS 6.5" You implied that if you have one (ANSYS for example) you get the other (CFX) without paying for an additional license. That's not true. You do have pay for licenses for each one. Your original statement was very misleading. The only thing you get for free is the interface.

steve February 7, 2005 16:56

Re: Fluid Structure Interaction (FSI)
STAR 3.15a can and has been run with both Abaqus and Ansys. I don't know the exact details, but its been linked with reasonably new versions. You would be best off talking to your STAR support office for all the details.

Harendra February 7, 2005 23:17

A little confusion

You are telling that " ANSYS 9.0 and CFX 5.7.1 and FLUENT 6.2 and ABAQUS 6.5" " : either of these two pairs is capable of doing FSI. But I found some links stating that someone needs to wait till CFX-5.8 and ANSYS 10 are released ( unless you use some third party interface.

Our department has Ansys 8 and CFX 5.7. Is it possible to simulate FSI?


F.K. February 8, 2005 09:35

Re: A little confusion
The current sold Ansys version is 9.0 and CFX 5.7.1

Ansys 10 and CFX 5.8 are under development

Robin February 14, 2005 14:04

Re: A little confusion
Hi Harendra,

ANSYS 10.0 and CFX-5.8 will be released this summer. If you have an ANSYS Multiphysics license, you also get CFX-5 basic capability, so there are no additional licenses required (contrary to previous posts). I still recommend that you contact your ANSYS representative for more details.

Regarding other FSI solutions, most require MPCCI, even if you have both codes. MPCCI is sold by a third party, so you will have to purchase additional licenses.

Regards, Robin

Jörn Beilke February 14, 2005 21:09

Re: A little confusion
So you are talking about nothing else than vapourware.

Robin February 15, 2005 21:57

Re: A little confusion
No, vapourware would be software that is planned but not yet under development. What ANSYS is releasing is already in full development and working.

Regards, Robin

steve February 17, 2005 12:25

Re: A little confusion
Well an Ansys multiphysics license is almost twice the price of a basic Ansys structural license. So I stand by what I said. You don't anything for free out of Ansys and certainly buying a structural license doesn't get you the ability to run CFX. If you want to run it, you have to pay for it. I don't really have a problem with paying for extra functionality but its misleading to say that it does not have a cost.

Robin February 18, 2005 22:13

Re: A little confusion
So who's going to give it for free Steve? Do you really expect ANY commercial software vendor to give the stuff away? At least with ANSYS it is all coming from one vendor, but I'd like to hear what you would recommend.


Peter Attar February 19, 2005 09:48

Re: Fluid Structure Interaction (FSI)
I've coupled ANSYS to two in-house CFD codes using the UPF(user programmable features) of ANSYS. Essentially "all" that needs to be done is to pass pressure(and/or temperature) and displacements back and forth between both codes which can be done by placing ANSYS UPF subroutine calls inside of the CFD code. I have no experience with STAR-CD so I'm not sure if it would be possible. The UPF capability is free but it does take a good knowledge of fortran.

steve February 19, 2005 17:45

Re: A little confusion
Robin you missed my point. I don't expect anything for free from commercial vendors. They are in business to make money and I completely respect that. We don't give away anything for free either. All I meant was, going back to my original post, we have an Ansys license but still can't run CFX because we have only a structural license. To get the ability to run both ansys and CFX you have to almost double your fee. Well whether you pay Ansys 2X or 1X to ansys and 1X to STAR, you still have to pay for a structural code and a fluid code. In fact at our site, we use Ansys and STAR and we do FSI with those two. I wouldn't give up my STAR license for a CFX license just because they come from the same vendor because I actually believe that STAR is a better code for what we do generally than CFX.

carsten February 20, 2005 14:38

Re: A little confusion
Hello Steve,

you are right. Nothing is for free, specially you'll never get an ANSYS/CFX license for the same price of ANSYS multiphysics. All ANSYS and CFX customers who run both codes since years would be glad to get both now for reduced license costs.

Bye the way, MpCCI is licensed software and not for free. The advantage of MpCCI compared to ANSYS/CFX pair is that with MpCCI you can couple a FEA and CFD code in any combination ANSYS/STAR ANSYS/Fluent ABAQUS/Star ABAQUS/Fluent etc.. In fact you never couple pairs of codes. Each code gets connected to the MpCCI coupling server. The Code never sees a partner application, only the MpCCI server.

MpCCI comes with a GUI (called Workbench in ANSYS/CFX) which handles all applications in a common way. There is NO need to setup any coupling stuff within you model data. The MpCCI modifies all your files automatically. You may just take old and already archived models and after a few minutes you can fire up a coupled FSI analysis.

The MpCCI used with ANSYS/CFX is more than three years old and ANSYS never upgraded MpCCI 1.3 to the current 3.0 version.

For ANSYS an up-to-date MpCCI is available. That version is not delivered by ANSYS, but by Fraunhofer SCAI (

MpCCI 3.0 is available on all platforms supported by ABAQUS, ANSYS(except AIX 4.3), Fluent, Star-CD and Thermoanalytics RadTherm/Muses.


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