{"id":397117,"date":"2024-12-11T15:19:38","date_gmt":"2024-12-11T15:19:38","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/generating-non-conformal-mesh-for-sliding-mesh-when-moving-domain-is-a-sphere-2\/"},"modified":"2024-12-12T10:15:04","modified_gmt":"2024-12-12T10:15:04","slug":"generating-non-conformal-mesh-for-sliding-mesh-when-moving-domain-is-a-sphere-2","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/generating-non-conformal-mesh-for-sliding-mesh-when-moving-domain-is-a-sphere-2\/","title":{"rendered":"Generating non-conformal mesh for sliding mesh when moving domain is a sphere"},"content":{"rendered":"

<p>Hi, I am trying to perform an external flow analysis of a rocket. To find the damping, I need to run transient pitching and rolling simulations. I am using a sliding mesh approach. However, I cannot get Ansys fluent meshing to detect the face zones properly and create a non-conformal mesh, specifically when the moving domain is a sphere. Everything works correctly when the moving domain is a cylinder.<\/p><p>My method for generating the geometry consists of the following:<\/p><\/p>\n

    <li class=”evensingle”>Use create enclosure on rocket body to create spherical or cylindrical moving domain.<\/li>\n

    <li class=”oddsingle”>Move the solid out of the enclosure component and rename to movingDomain and delete the empty component.<\/li>\n

    <li class=”evensingle”>Use create enclosure on ‘movingDomain’ solid to create staticDomain.<\/li>\n

    <li class=”oddsingle”>Move the solid out of the enclosure component and rename to ‘staticDomain’ and delete the empty component.<\/li>\n

    <li class=”evensingle”>Delete\/hide and suppress the original rocket body<\/li>\n

    <li class=”oddsingle”>Create named selections:<\/p>\n

      <li class=”evensingle”>Outside faces: ‘far-field’<\/li>\n

      <li class=”oddsingle”>’staticDomain’ inner face(s): ‘interface-static’<\/li>\n

      <li class=”evensingle”>’movingDomain’ outer face(s): ‘interface-moving’<\/li>\n

      <li class=”oddsingle”>’movingDomain’ object faces: ‘wall-xxx’<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n

      <p>Below are the results of this process when using a sphere as the internal sliding mesh interface or a cylinder as the interface.<\/p><p><\/a><\/p><p><\/a><\/p><p><\/a><\/p><\/p>\n

        <li class=”evensingle”>Next I use the workbench->fluent 2024 R2->watertight workflow button to move to fluent meshing.<\/li>\n

        <li class=”oddsingle”>The difference between the two cases appears when running the ‘generate the surface mesh’ task. <\/p>\n

          <li class=”evensingle”>For the sphere case, a new face zone is auto-created called far-field:xxxx, and no ‘generate non-conformal mesh’ option is available under describe geometry task<\/li>\n

          <li class=”oddsingle”>This far-field:xxxx face zone remains throughout the rest of the process and then causes issues when switching to solution mode as far-field:xxx face zone is the same as the ‘interface-static’ zone. Basically, somehow, an extra face or face selection is created on the sliding mesh interface. Which results in an extra boundary.<\/li>\n

          <li class=”evensingle”>This also happens when selecting the share topology option in fluent meshing OR selecting share topology in SpaceClaim or Discovery before importing. (I tried this even though I need a non-conformal mesh for the sliding mesh analysis)<\/li>\n

          <li class=”oddsingle”><\/a><\/li>\n<\/ol>\n<\/li>\n

          <li class=”evensingle”>When clicking generate surface mesh task in the cylinder case:<\/p>\n

            <li class=”oddsingle”>This works as intended: No new ‘fair-field:xxx’ face zone is created.<\/li>\n

            <li class=”evensingle”>Non-conformal mesh between objects is available in describe geometry<\/li>\n

            <li class=”oddsingle”>Finishing meshing and switching to solution mode shows that all the boundaries are generated properly and that a sliding mesh analysis can be run.<\/li>\n

            <li class=”evensingle”><\/a><\/li>\n<\/ol>\n<\/li>\n<\/ol>\n

            <p>If anyone has an idea why there might be a difference between these two cases, please let me know. It seems like a bug or error to me. The only difference I can think of is that in the case of the cylinder interface, there are a number of edges present, while in the case of the sphere, there are no edges. While waiting for a reply, I will try imprinting an edge on the sphere to see if that changes the results. <\/p><p>Using a sphere as an interface is rather important for me as I need to be able to rotate the inner sphere in arbitrary directions. Generating a new mesh with a cylinder perfectly matching each angle would be basically impossible. <\/p><p>Please note that I have also tried several different ways of generating the same input geometry. For example, I created the whole enclosure and sphere and then used the combine tool, or I manually created every solid.  Either way, the results are the same.<\/p><\/p>\n","protected":false},"template":"","class_list":["post-397117","topic","type-topic","status-closed","hentry","topic-tag-ansys-fluent-meshing-1","topic-tag-cad-import","topic-tag-cell-zone","topic-tag-sliding-mesh","topic-tag-sphere"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t