MESHING A PRESSURE VALVE USING ANSA

OBJECTIVE:-

To clear the topo errors , mesh the model for various element size of 10, 20, 40 units and to conclude which element size will be the best to mesh.

PROCEDURE:-

CLEARING TOPOLOGICAL ERRORS:-

The following tools are used to clear the topo errors on the wall portion.

• [Not + PID Region and then selected Invert] is used to make visible only the selected portion.
• [going to COONS under surfaces - then selected all the edges and then middle click - then selected ok] is used to fill the empty spaces by creating new surfaces.
• [going to Cut option under faces - ensure whether the heal cut is enable under option list - then selected the two nodes] is used to create the small portion in the surface.
• [going to delete option under hot points] is used to delete the unwanted hot points.
• [going to fill hole under cons - the selected the edges - clicked on ok] is used to fill the empty space on the same surface itself (it won't create seperate surfaces).

Before correction After correction

The following tools are used to clear the topo errors on valve seal and valve springs.

• [going to intersect option under faces - then selected the first surface by middle click and then the second surface by middle click] is used to intersect the two selected surfaces.
• [going to universal delete option - selected the unwanted surfaces by using PID Region option and then middle click] is used to delete the surfaces.
• [going to COONS under surfaces - then selected all the edges and then middle click - then selected ok] is used to fill the empty spaces by creating new surfaces.

Before correction After correction

ASSIGNING PID'S:-

• Intially the model is in single PID to seperate it by [going to set PID under faces - selecting faces / shells - then selected the surfaces that need to be seperated]

- First the wall is created and coloured it in skyblue colour.

- Next the valve seal is created and coloured it in pink colour.

- Next the valve spring is created and coloured it in blue colour.

- Next the outlet is created and coloured it in yellow colour.

- Finally the Inlet is created and coloured it in lavendar colour.

CREATING SURFACE MESH:-

• Before performing mesh Initially changed from Topo Mode to Mesh Mode. we are going to perform the same model for different element size of 10,20,40 units by [ going to length under perimeters - selecting perimeters - selected the model by dragging and then middle click - changed the length to 10,20,40 and then clicked ok ] after changing the node to 10,20,40 units ensured whether it is changed or not by [ going to measure - selecting nodes - then selected two nodes] and in our case it is observed that the node distance is changed to 10,20,40 units.
• Then created mesh by [ selecting spot mesh under mesh generation - and changed the element type to tria under option list - then selected the model by dragging and then middle click] and the equilateral triangular mesh is created.

OBSERVATION:-

1. FOR ELEMENT SIZE OF 10 UNITS

• Trias formed is more when compared to the other two models which is 2814.
• The unmeshed and unchecked areas is less when compared to the other two models which is 1.
• The meshing is fine when compared to the other two models.
• Only one clash is observed between the seal and the spring.

2. FOR ELEMENT SIZE OF 20 UNITS

• Trias formed is less when compared to the above which is 1186.
• The unmeshed and unchecked areas is more when compared to the above which is 2.
• The meshing is not good at the edges when compared to the above.
• Two clashes is observed one is between seal head and the wall and the another one is between seal and the spring.

3. FOR ELEMENT SIZE OF 40 UNITS

• Trias formed is less when compared to the above two which is 778.
• The unmeshed and unchecked areas is more (when compared to the mesh done for 10 units) which is 2.
• The mesh is not good at the edges when compared to the above all.
• Two clashes is observed one is between seal head and the wall and the another one is between seal and the spring.

CONCLUSION:-

Meshing size of 10 units is best when compared to the other two model because in the other two models two unmeshed areas are observed where as in 10 units only one unmeshed areas is found.Also usually smaller mesh size gives more accurate results.