Learning Forum

[h_pigg]

I am new to Ansys and AQWA and am trying to run a hydrodynamic diffraction simulation on a wave energy converter. Everything in the tree seems to check out until I try to solve the simulation. When I try to solve I end up getting errors saying element number X is less than the minimum of 0.10 * facet radius from its neighbor. I do not know what this means or how to approach fixing it. nWhen I play around with the mesh, I can sometimes solve hydrostatics but when I attempt a full solve, I then get an illegal connectivity error. I also do not know how to solve this error.nAny help would be greatly appreciated!!n

[Yu Bi]

Hi, regarding the first error message element number X is less than the minimum of 0.10 * facet radius from its neighbor, it is due to the Aqwa Mesh Quality Check. You can find more information about it in the Aqwa Theory Manual Section 4.1.4. You can adjust the mesh size or turn on Ignore Modelling Rule Violations option in the Details Panel of the Analysis Settings of Hydrodynamic Diffraction.nRegarding the illegal connectivity error, it might be caused by the intersecting surfaces in the geometry or improper mesh in some narrow area. The suggestion I would give you is first making sure that there is no intersecting surface in your geometry and second using the Ansys independent mesh tool to do the mesh instead of using the Aqwa internal mesh tool. Also, please make sure your geometry has been split exactly by the waterplane.nHope this helps.n

[h_pigg]

Hi, regarding the first error message "element number X is less than the minimum of 0.10 * facet radius from its neighbor", it is due to the Aqwa Mesh Quality Check. You can find more information about it in the Aqwa Theory Manual Section 4.1.4. You can adjust the mesh size or turn on "Ignore Modelling Rule Violations" option in the Details Panel of the Analysis Settings of Hydrodynamic Diffraction.Regarding the illegal connectivity error, it might be caused by the intersecting surfaces in the geometry or improper mesh in some narrow area. The suggestion I would give you is first making sure that there is no intersecting surface in your geometry and second using the Ansys independent mesh tool to do the mesh instead of using the Aqwa internal mesh tool. Also, please make sure your geometry has been split exactly by the waterplane.Hope this helps.https://forum.ansys.com/discussion/comment/98909#Comment_98909

Thank you for the response! I attached this photo of my geometry from SolidWorks, do you think a source of error may be from the pinned connections? Or maybe the elliptical flaps are too close? Also, where do I find the independent mesh tool?n

[Yu Bi]

Hi, yes, the pinned connections and very close elliptical flaps could all be possible reason for the error. Aqwa doesn't accept the contact of two surfaces. The surfaces should have some distances.nAbout the independent mesh tool, I mean the mesh tool in the Toolbox of Workbench. Please see the graph below.n nn

[SARVALOGAPATHI SUBRAMANIAN]

Hi,

After the simulation, I am getting an error message like in the attached image. How to fix this error?

Thank you..