Week 2 Challenge : Surface meshing on a Pressure valve

Please refer the word file attached below as there are 100s of images has taken up. Important images are inserted here.

Week 2 Challenge : Surface meshing on a Pressure valve

OBJECTIVE:

For the given model, check for the geometrical errors and perform Topology cleanup accordingly. Set three different target lengths as three different cases and mesh the model.

• Target length = 1mm, 3 mm and 5 mm (i.e. 3 cases)
• Element type = Tria

Apply any one target length from the above at a time for the entire model as One case. Submit 3 different models for 3 cases.

WORKING ON ANSA:

1. Select topo for topological cleanup

2. W will do geometry check

Click on templates

There so many in built checks

First is selected

some more checks that ANSA does

After executing will give below errors:

gives this much errors need to solve

The surfaces that are not shared with true surfaces ie. Yellow

This is single con as one surface need to resolve

Select any error will highlight the error in geometry

selecting only single con and will solve for single con for now

when hole is present in existing surface to fill it

Con is a line that constitutes in making of invalid surface like hole

select all the cons of hole

click on cross hatches to get a surface in hole

it means when we select one line, the other lines in loop will get selected

We cant use fitted here for this polygon

turn off these to get how many holes are left

ctr + shift together to get wireframe mode

These are double cons

There are no vertical cross line

We will generate face from 2 single cons only when both are having equal length check in wireframe mode

select all the single cons to create surface. On wireframe double click to select con

no alternative surface and generated surface preview not correct as we need vertical surface

In CFD analysis we need model with closed surfaces

Still bottom open

showing status of errors

like curved inward surface formed that is wrong

But triple con is not always wrong or error so in this case its not wrong

1 is to get adjacent body get back to which we click on

2 gives all neighbour surfaces to the visible surfaces on screen

3 shows everything

Topo clean up:

single cons clean up

turn off 2 n 3 cons along with hot points, cross points

Now on only wireframe mode n off shadow mode

No 1 con is reflecting. Similar for 2 cons

These are not errors

its disturbing correct curve of surface here. So need to remake it

These cons are not errors but small surfaces can be error while doing meshing.

If length and width of any surface<=5mm then we need to omit that surface

Using cut option,

Click on cut and rub over the line and check its color is different from surrounding

same

PID mode and how to assign PID

Selecting PID region mode to select outside body

To check the deleted surfaces

White are deleted surfaces. this will show the surfaces that are intentionally deleted by me

And we want to restore any surface then after click on undelete then select the surface you want then green cross symbol then middle ball button click

2 surfaces overlapping

After doing restore its must to use topo to do proper connectivity between surfaces by drag mouse over the region

This gives a triple con connection that is not error if 3 surfaces are connecting except no overlap but here we can see 2 colors og 2 overlapping surfaces

We need to delete 36th pid

but here every thing is fine in point of double and triple cons

Now moving to mesh the product

1. Target length of mesh = 1mm

Target length of mesh = 5mm

2.

3. Target length of mesh = 5mm

Results:

Mesh size	inlet	outlet	body	spring	Valve head	Base surface	column	total
1mm	7590	16824	124692	10964	28320	2110	19228	209740
3mm	824	1878	14348	1288	3146	240	2146	23870
5mm	298	676	5296	388	1148	82	938	8826

Conclusions:

1. Number of meshes increases with length of mesh decreases.

2. Even the fine profiles of any 3d geometry can be captured with fine meshing only. It loses its fine curves and profiles if mesh size increases as we had discussed that the distance between 2 edges must be less than the mesh length.

3. As per the size of product parts, we must require to mesh them as per the requirement so that its profile should not get missed out.