How to create O-grid, C-Grid or Y-Grid to avoid singularity on revolved object?

jlheejlhee United KingdomMember

Hi,

I am planning to use ANSYS ICEM to create a fully structured mesh for a region as shown in the image.

Imagine you have a circular cylinder, and when moving along the axial direction, a round oval object obstructed the circular conduit and causing bifurcated flows. This obstructive object is not fully blocking the outer radius and the curvatures are well mapped. 

I was able to get a very good mesh using ANSYS workbench where I split the control volume into multiple segments and combine sweep mesh and tetra mesh resulting in the prismatic hybrid mesh. 

I saw some videos online on how to revolve a 2D surface mesh to 3D mesh, however one biggest issue I am facing is singularity mesh at the stagnation point of the bullet. 

Could someone kindly advise how I could get rid of it? I tried to create O-Grid in 2D and revolve as well as create 4 quadrants and O-grid it! Things got complicated and it doesn't seem to work well. 

My idea is that I want to have prismatic layers on outer surface and inner surface of the tip so it captures the Boundary layer, and in the middle or stagnation area of the object, the cell grows such that the physics at the tip is captured. 

Any idea?

Thanks

J


 

 

 

Comments

  • RobRob UKForum Coordinator
    edited April 28

    Which solver are you using? I had to do some of this for my PhD over 20 years ago, and find that inflated poly cells are much easier now. 

  • jlheejlhee United KingdomMember
    edited May 19

    Hi Rwoolhou,

    Thanks, sorry been busy.

    Yes, I have during the past few months been using ANSYS AM and created hybrid mesh based on prismatic tetra + sweep (hexahedral mesh+prism) and converted them to Poly in Fluent, convergence criteria is very good. 

    I was planning to achieve highest convergence criteria and reduce numerical diffusivity by attempting to create fully structured hexa-mesh because research partner was having issue with getting same results with their mesh. 

    So far, I just accepted the poly-prismatic mesh as the baseline mesh. 



  • RobRob UKForum Coordinator
    edited May 20

    It's doable, but more a case of you working out how to add the blocks. I think an O-grid will do it, but I'll have to leave you to figure out how to attach the blocks. 

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