[jdietz224]

I am trying to make a simple mesh for a two-dimensional pipe in Pointwise. When I try to revolve my rectangular mesh into three dimension, I encounter no errors during the extrusion. However, when I hit "OK" to finish the extrusion step, I encounter an error that said "1 extruded block could not be saved", and the extrusion would fail.

Here is a link to the grid file: https://www.dropbox.com/s/p4uqqukpge32o0c/grid.pw?dl=0

The extrusion was as follows: I used a Rotate extrusion of 1 degree in 1 step, about a line parallel to the x-axis, containing the point (0, -1e-6, 0).

I know that this is related to the spacing constraints on the upper edge of the rectangle, because if I relax the constraints, it works fine. Specifically, a spacing constraint of 1e-7 seems to work, while a constraint of 1e-8 will fail. I've already tried setting the tolerances as low as they will go, and that doesn't fix the problem.

I looked around and I've been unable to find anywhere that even mentions this error before, so I would appreciate any help in addressing this issue.

[dgarlisch]

The header of this file indicates Pointwise V18.0R3

The grid extents are 7.75 units.
The Model Size is 1000.
Initial Spacing is 1.0e-8.
The Node, Connector, and Grid Point tolerances are set to 1.0e-34.

The Model Size of 1000 combined with the Initial Spacing of 1.0e-8 results in a dynamic range of 11 orders of magnitude (OM). This puts your model right on the limit of Pointwise's supported precision of around 10 OM. This can result in unexpected behavior as you are seeing in the rotation failure.

There are several things to fix:

• Considering the grid extents and the very small Initial Spacing, the Model Size should be 10.0. Changing this value alone will enable rotation to succeed.
• For a Model Size of 1000, the 1.0e-34 tolerance values are too small. They should respect Pointwise's ~10 OM limit.
• Considering the Initial Spacing, the Grid Point tolerance should be 1.0e-9.

The rotational extrude will succeed with the proper settings.

The new Model Size of 10 and the Initial Spacing of 1.0e-8 results in a dynamic range of 9 OM. This is on the "good side" of the Pointwise limit.

[jdietz224]

This fixed the problem. Thanks for the help!

[dgarlisch]

Originally Posted by jdietz224

This fixed the problem. Thanks for the help!

Glad to hear that. Are you sure you need an Initial Spacing of 1e-8?

You can use the Pointwise Online Y+ Calculator or the Pointwise Smart Phone App to calculate a good Initial Spacing.