Inflation into helical structure

Hello there,

How can I create a smooth inflation layer on the helical structure in the photo? Inflation does not come from beginning to end. I choose four surfaces, one does not form one at all, and the others do not reach the bottom surface of the helical.

Thank you in advance for your help.


  • Does the geometry show as Sweepable?

    If so, you want to define the sweep Source face to be an end face. Then you put inflation on that face and the boundary are the edges of that face.

  • Thank you for your answer.

    Yes it looks sweepable. When I do the sweep method, inflation occurs, but when I do the initilization, I get the warning that there is no converge. Then the solution does not converge. In addition, when the helicals sweep, the orthogonal quality average drops to 0.5. For this, I want to get inflation using the patch conforming method, but it does not work properly.

    Can I let him converge using sweep or how can I properly inflate using patch conforming?

  • @fatih29

    The average orthogonal quality is less important than the minimum orthogonal quality. What is the minimum?

    You might get better results if you use one or more planes to slice the helix into shorter segments. Make sure the plane is approx. normal to the helix.

    Please use the Windows Snipping Tool to capture screen snapshots and paste them directly into your reply.

    Why do you want patch conforming method? It is more important to have good inflation.

    Once you have a good mesh, open a discussion in the Fluids category. There will be more people reading that who can answer the question about initialization and convergence.

  • Thank you for your answer.

    The reason why I want to inflation using patch conforming is because I applied a similar structure before and I achieved convergence in hybrid initalizone. Accordingly, I reached the solution. Likewise, when I applied sweep, I could not reach the solution. Here I change the angle of the helix, as before, I cannot perform proper inflation in patch conforming.

    I'm adding the photos.

  • peteroznewmanpeteroznewman Member
    edited September 13


    Please delete the mesh, save the project and File, Archive to save a .wbpz file, then put that in a .zip file to attach to your reply by using the paperclip icon. I will have a look at the geometry and the meshing problem. What version of ANSYS are you using?

  • peteroznewmanpeteroznewman Member
    edited September 13


    Your .rar file does not contain the helisel.wbpj file so I cannot open your Workbench project.

    Both the helisel.wbpj file and the helisel_files folder are needed to open a Workbench project.

    When you use File, Archive, it creates a .wbpz file that contains both those items.

    I was able to dig out the SpaceClaim file from the folder, so I will work with that.

  • peteroznewmanpeteroznewman Member
    edited September 13

    If you cut off the angled ends, you get a very good minimum orthogonal quality mesh. Do you need those ends?

  • Thank you for your attention. You allocate your precious time for me, I am grateful to you, I hope we will come to a conclusion.

  • If there is no other way, I can do this without changing the dimensions. So how do I cut these angled ends?

  • Download the zip file from my post above and open the Geometry cell in SpaceClaim and you will see the two planes I used to slice off the angled ends.

  • I understood what he meant. The parts you cut are part of the geometry. If they are cut off, the problem is altered.

  • You cut this helix from something, so you altered the problem when you made the cut you did. I am suggesting you choose a cut that makes it easy to mesh instead of difficult.

  • Thank you.

    This helix was created like this in the problem, so I didn't cut it. Geometry drawn on the underside of a cylinder followed the helix to the upper surface.

  • So at the bottom end of the helix, there is a cylinder of fluid, which has a circular wall with one small rectangular hole where the helix starts. There was a choice on where to draw the system boundary. One choice would have been to include some of the cylinder and capture the flow from the large cylinder into the rectangular hole. That would be the most accurate because it would capture the flow into the hole. Your geometry sets the boundary at the plane of the circular face, which excludes the nature of the flow being developed in the cylindrical part of the fluid. But because of the angle of the face relative to the helix, this choice makes meshing difficult and makes defining the inlet boundary condition more difficult. The simpler cut is to be normal to the helix, which makes meshing and defining the inlet boundary condition easy.

    If the other end of the helix is a pressure outlet, does it matter if the face is normal to the helix or at a cut angle? The cut off part is a small percentage of the total surface area.

    Simulation provides an approximate solution to the real problem. Small approximations to make the model easy to build and solve are often made to get answers quickly.

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