To mesh a given pressure valve model in ANSA using various element sizes and comparing their result as to which element size is the best for meshing any complex geometry.
The link for the files for this challenge is: https://drive.google.com/drive/folders/1fhJnXQL9HtcO3CGxrmVFqQVm4BSpy9ZW?usp=sharing
OBJECTIVE:To mesh a given pressure valve model in ANSA using various element sizes and comparing their result as to which element size is the best for meshing any complex geometry.
STEPS INVOLVED:
1. To analyse the model for any geometric abnormalities and to fix them up by geometric cleanup. For this step we first loaded the part in ANSA and then performed geometric cleanup with the help of the check manager and doing a geometric cleanup.
In the above figure you can clearly see that the figure has many geometric abnormalities like surfacce cracks, face missing etc.
These were the errors that i came across during geometric cleanup.
In the above image we can see that the geometric checks have been completed.
2. After geometric cleanup for the outer case the cleanup for the spring valve was to be done. For this we had to treat the double cons and convert them into triple cons by cleaning up all intersecting surfaces and deleting all unwanted surfaces.
For this operation i used the intersection command in the faces section in the topological module of ANSA.
3. After the geometric cleanup waas done now we had to set the properties ID for each surface which will be then further used in CFD analysis. For this we used SET PID command to set the various properties in the geometry.
4. Now we use the mesh module to perform the mesh. To enter the element size of the mesh we use the perimeters tab in the emsh module. After that we use the length module and select the geometry for which we need to give the element size.
The 3 element sizes that we have to compare are:
a) 15 mm
b) 7 mm
c) 2 mm
We can enter the element size inside the length command.
5. Finally we go to spot mesh and mesh the geometry by selecting the whole geometry.
RESULTS: The meshes for the above given element sizes are as follows:
a) 15 mm
b) 7 mm
c) 2 mm
While changing the element size i observed that the geometry is becoming more refined as we keep on decreasing the element size and that the nodes that we chose earlier also converge due to minimal size and equal distribution among the surface.
CONCLUTIONS:
I always prefer perfection over any other parameter. But in such cases there has to be a balance between the refinement of the mesh and the computing time it will take when this mesh will be used in a CFD analysis.
I would prefer to take the element size to be around 5-7 mm as it would make the mesh a little more refined than 15 mm and would also have reduced computing time thereby increasing its efficiency and providing better results.