I have case of a rotating fan at Low- speed ie about 300-400 rpm. I have successfully carried out RAS simulations using cyclicAMI approach where, the motion of the fan is modeled as rigid body rotation of a cylindrical AMI mesh section, which has same speed as our fan. I have tried various levels of mesh refinement and differing y+ and so forth.

I would like to know if there are any other methods of modelling this problem, as I am not able to predict some important parameters accurately. For the attached mesh I used solidBodyMotionFvMesh for rotating inner domain/cyclicAMI. I am looking into dynamicFvRefineFvMesh and dynamicMotionSolverFvMesh for rotating the fan.

please let me know which other approach is suitable and how to set-up the mesh for such case (pointers to examples would be great)

PS : Motion of the fan is strictly rotation about a fixed axis.

I would like to know any other way (except below accepted answer) of conducting this simulation.[cry for more answers]

AMI mesh


1 Answer 1


You can do a simulation using the MRF (moving/multiple reference frame) approach. For this you need to create a cylindrical cell set that is aligned with the axis of rotation. There are some cases in the OpenFOAM tutorials that make use of this approach. You can also consult e.g. the Fluent Manual for some theory behind MRF.

With MRF there is no actual mesh motion, so the simulation will be faster than with a moving mesh. However, this method is less accurate than a simulation with a moving mesh.

  • $\begingroup$ but MRF solver's are phased out in favor of pimpleDyMFoam in OF 2.1 and above (we are using 2.1 and 2.2), if you could, can you elaborate a bit how to do MRF simualation with dyMFoam solvers and what is SRF? specifically SRFSimpleFoam and SRFPimpleFoam $\endgroup$
    – fedvasu
    Mar 5, 2014 at 8:23
  • $\begingroup$ Yes, the MRFsomethingFoam solvers are gone. However, the method is still around. With pimpleFoam the MRF method is available using the fvOptions framework. Check out the release anouncement of OF-2.2 [openfoam.org/version2.2.0/fvOptions.php] There has been some changes over the last versions of OF, I started using OF with version 2.0. So, take a close look on the mixerVessel2D tutorial cases in both OF-2.1 and OF-2.2 to examine the differences between these two versions. $\endgroup$
    – Dohn Joe
    Mar 5, 2014 at 8:30
  • $\begingroup$ the *DyMFoam solvers are used for cases with moving and/or changing meshes. MRF, in contrast, does not use any mesh motion. Thus, MRF is used with the plain pimpleFoam solver. At least, this is the case for OF-2.2. $\endgroup$
    – Dohn Joe
    Mar 5, 2014 at 8:32
  • $\begingroup$ I will take a closer look at mixerVessel2D, also there is a mixer problem with SRFPimpleFoam as tutorial and read the fvOptions change. $\endgroup$
    – fedvasu
    Mar 5, 2014 at 8:36
  • 1
    $\begingroup$ You have to be careful with the versions. The fvOptions framework seems to be a feature of OF-2.2. SRFpimpleFoam is a solver of OF-2.1. SRFpimpleFoam is gone in OF-2.2. $\endgroup$
    – Dohn Joe
    Mar 5, 2014 at 9:12

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