Blocking and Meshing around a vane vortex generator
 

Hello all,

I have been working on a CFD project and during the blocking and meshing stage I have decided to use ANSYS DesignModeler and ANSYS Meshing, simply due to availability and ease of use.

The domain is intended to represent an open flow over a backward facing hump geometry, which induces flow separation. This also includes a low profile vane and the preliminary blocking strategy is shown in the attached image (blocking.png). The difficulty lies in trying to maintain a consistent and geometrically similar meshing strategy with biased sizing, mesh method and other techniques. This should be maintained, while the vane moves further away from the leading edge with each of the design iterations.

Currently, using the same blocking strategy and biased sizing provides significant variation between the initial vane position geometry and the final position (Fail Position.png). The Orthogonal quality drops from 0.35 min to 0.025 min and this is obviously unacceptable. Currently the meshes are Approx. 1.5-1.6 M cells in size.

Please suggest a blocking strategy which could possibly be more flexible as the vane moves rearward. I am currently using a multi-zone method having hexa mapped mesh type and hexa-dominant free meshes. This also used proximity advanced size function and overall my intention is to change the parameters in DM and update the meshes repeatedly with every new location.

I have found that the best orthogonal quality resulted from restricting the mesher to hexa mapped mesh types only however, this introduces wedges into the domain (vane1.png, vane2.png, vane3.png)

I have spent a lot of time on this so I would really appreciate some helpful suggestions.

Does anyone have any further suggestions for the blocking and meshing of this flow domain?

Please provide some guidance if any of you have experience with similar problem definitions or flow domains. I realise that it may be much easier if the overall envelope for the domain is placed much further away from the VG however, it is very important within my study and for validation to use this tunnel geometry.

I look forward to some comments and I really appreciate the time.

Maybe if you provided the geometry itself someone could help.
I actually cant distinguish blocking from geometry in your previous pictures.

I didn't really think it was possible to attach the geometry file or the mesh files I created. I wanted to share a zipped folder however, the folder size is too large and even the GEOM file is 455 kb >> 97 kb limit. :confused:

I will upload this through FileFactory file hosting services and hopefully this will work. http://www.filefactory.com/file/487q...-VG-Geom60_zip

Please share with us if you have any ideas.

I have some additional information which may be of interest -

• I am testing this with Standard Atmospheric air at 25 Deg. C

• The Reynolds number for the flow domain was calculated to be 80 000 based on the streamwise distance x along the intake runner surface.

• Ultimately, I need to vary both the incident angle of the inlet flow and also the height and streamwise position of the VG.

I look forward to some comments and suggestions. I really need to progress quickly with this so will appreciate the help.

Have you completed your work? Would you please share?
Thanks