Week 2 Challenge : Surface meshing on a Pressure valve

Aim:

To study surface meshing on given geometry, Making three different models with 3 different target lengths.

Geometry:

The model provided has many flaws which are to be corrected before meshing

Given Geometry

As we can see there are many problems there are many single cons and open holes in geometry

So we can perform a geometry check inbuilt in ANSA

After executing we can find all the errors in the geometry, so we can work on them one by one

SINGLE CONS

This all shows the open spaces in the geometry, to overcome them we have to fill them before meshing

To fill the holes, we can use New command from face dropdown, in which we can new faces on the holes in the geometry

As shown above we can fix all the gaps in geometry, also ANSA shows alternate option in all the faces to create a face according our requirement

After fixing all the holes also the Inlet and Outlet the geometry looks like this

Now, we can perform Geometry check to check for any other errors, before meshing we need to check while making new faces have, we made any new cuts are which are very close to each other if there are then we need to delete them

As shown, we need to delete them by using CUT option and clicking right click on the cut

Now, the clean-up of the geometry is done so we can start with meshing and a coplex geometry like this we need to assign PDI to each component to facilitate the meshing part and also regulating any new clean up or selection of geometry, by doing this it becomes very easy to handle the complex geometries while meshing

As shown by choosing new we create a new PDI and then we assign them to any part

The bulb sign in the side of PDI shows that the PDI is visible

As you can see, I have hide body in above pic. Like this it becomes easy to handle the geometry, we need to assign PDI for every part so we can handle the geometry more easily

MESHING:

• Target length 5mm

Minimum length = 3mm

Maximum length = 7mm

This is how it looks from outside shape is good enough to make an over all calculation may be the accuracy will not be that good but it can be enough to make calculations but when we look at the smaller part in the geometry it may have loosed it shape as the mesh size is big for them

Total no. of cell = 8812 nos

As you can see as we look into the smaller part of geometry the shape is not that sharp and accurate the spring has lost its shape completely

• Target length = 3mm

Minimum length = 1mm

Maximum length = 5mm

As you can see the shape looks sharper and more accurate

Total no of cell = 23912

As the no. of cell increases the time for calculation increases so the cell size should be according to the required accuracy according to me 3mm is good for outer body as it will show more accurate result then 5mm

Also, internal parts also look good the dome shape of the head is still good but spring doesn’t looks accurate we may need to reduce the target length for spring

• Target length = 1mm

Minimum length = 0.5mm

Maximum length = 1.5mm

As we can see the mesh size is very fine for the exterior body as the component is big

Total no. of cell = 209910

For the body 3mm is good as with so many cells it will take a lot of time to calculate and the result might be almost same, we can always different the mesh length along the parts so for the smaller parts we can use 1mm for more accuracy

As we can see the dome shape looks good

Also, springs looks good with small mesh size its shape looks good and it is good for calculations

CUNCLUSION:

• With fine mesh size the accuracy increases but the time for calculation also increases
• We can make two different target length according to the size of parts and required accuracy, in this case the outer casing mesh size can be 3mm which is not so large and not that fine earthier for good and accurate result
• For the smaller parts like the spring and the column head the mesh length can be 1mm so the accuracy for smaller parts increases too