[hudehfu]

Hello everyone：
When I started running the simulation，the following warning appears before reading the file.

1850 WARNING: There may be an alignment error.
The maximum dot product of the motion vector with a non-moving or reloft triangle's normal vector is 5.418371e-04.
For properly aligned moving surfaces, this dot_product should be less than 5.0e-4

1851 WARNING: The boundary type that appears to not be aligned is WALL, and it is attached to boundary 1, which is moving.
The triangle of maximum alignment error is centered at -1.149003e-02 -3.960107e-02 -2.961063e-02

Will these warnings affect the simulation? What is the cause of these warnings?

[ksrivast]

Hello Tianyuan,

When non-moving boundary triangles are attached to moving boundaries, CONVERGE will check for alignment errors. For example, for an IC engine simulation, you want your liner triangles to be aligned to your piston motion direction and thus be perfectly cylindrical. If not aligned (ex. a tapered liner), your simulations might face mass conservation issues as the non-moving triangles stretch/compress when the moving triangles they are attached to move.

You are strongly recommended to rectify these alignment issues in your geometry before running your case.

Sincerely,

[hudehfu]

Originally Posted by ksrivast

Hello Tianyuan,

When non-moving boundary triangles are attached to moving boundaries, CONVERGE will check for alignment errors. For example, for an IC engine simulation, you want your liner triangles to be aligned to your piston motion direction and thus be perfectly cylindrical. If not aligned (ex. a tapered liner), your simulations might face mass conservation issues as the non-moving triangles stretch/compress when the moving triangles they are attached to move.

You are strongly recommended to rectify these alignment issues in your geometry before running your case.

Sincerely,

Dear ksrivast：
thank you for your reply. I have a few more questions as follows:

What effect does this error have on the simulation?
How do I locate the geometric location in the model where the error occurs?
Can I find the place where the error occurred in CONVERGE?
Can I fix this error in CONVERGE?

Looking forward to your reply. I also want others to help me, thanks.

[ksrivast]

Hello Tianyuan,

1. Your simulations can face mass conservation issues if you have this error.
2. CONVERGE has reported the boundary ID the misaligned triangles were attached to. For your case, it is boundary ID 1. Please check alignment of all triangles attached to boundary ID 1.
3. CONVERGE has also reported the x,y,z location of the affected triangle in the log file. Thus, you can easily find the geometric location in CONVERGE Studio.
4. You would need to properly align your triangles in your surface file to fix this issue.

Sincerely,

[hudehfu]

Originally Posted by ksrivast

Hello Tianyuan,

1. Your simulations can face mass conservation issues if you have this error.
2. CONVERGE has reported the boundary ID the misaligned triangles were attached to. For your case, it is boundary ID 1. Please check alignment of all triangles attached to boundary ID 1.
3. CONVERGE has also reported the x,y,z location of the affected triangle in the log file. Thus, you can easily find the geometric location in CONVERGE Studio.
4. You would need to properly align your triangles in your surface file to fix this issue.

Sincerely,

Thanks again for your reply。
What is the operation flow of alignment？ Or where can I get the learning materials for alignment operations?
I hope you can give me some guidance，thanks.

[ksrivast]

Hello Tianyuan,

Please attend our CONVERGE for IC Engines introduction training sessions, or have a look at the training slides available in our downloads webpage, where we go into detail on how to check for and properly align triangles attached to moving boundaries. Ex, that of Liner and valve top.

Sincerely,

[hudehfu]

Originally Posted by ksrivast

Hello Tianyuan,

Please attend our CONVERGE for IC Engines introduction training sessions, or have a look at the training slides available in our downloads webpage, where we go into detail on how to check for and properly align triangles attached to moving boundaries. Ex, that of Liner and valve top.

Sincerely,

Thank you very much for your reply.
But I didn't find the training slides you mentioned. Can you send me a training slide by email or a link to the download ?

Thank you very much again

[ksrivast]

Hello Tianyuan,

If you haven't already, please register to create an account on our website. Once approved, you can login to your account and access the training material.

Sincerely,

[hudehfu]

Originally Posted by ksrivast

Hello Tianyuan,

If you haven't already, please register to create an account on our website. Once approved, you can login to your account and access the training material.

Sincerely,

Thank you for your reply. I have registered my account。 But I couldn't find training material。May I ask which module I can find the training materials in？

[yli]

You can register for any of your upcoming training session (online) from our calendar and our coordinator will share the training material/cases with you.



For converge documation (manual, etc.), you can find in

YOUR_CONVERGE-PACKAGE/Convergent_Science/CONVERGE/3.0.20/doc