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Home Forums ANSYS Fluent Beginners to Advanced level Lesson 8: Meshing a rotational periodic geometry.

• # Lesson 8: Meshing a rotational periodic geometry.

Posted by on February 9, 2024 at 4:43 pm

Sir, can I know what is the error happening here?

replied 2 months ago 3 Members · 11 Replies
• 11 Replies
• ### MIDHUN

Member
February 12, 2024 at 10:41 am

Hi,

You need to select both periodic labels and give proper angle value in case of Manual -pick reference side method

For Manual –pick reference side method is the periodicity angle needs to be specified or it can be measured (in SCDM for instance) using the geometry’s arc angle and arc radius rather than using the angle between objects and their minimum distance. But in case you know the number of blades you can also calculate the angle by (Number of blades/360). If the angle angle two sides are properly selected the error can be removed.

Alternatively you can also choose Automatic – pick both sides it fails periodicity angle

when sector angle is small (for example, smaller than ~10 degrees), in which case, the Manual –

pick reference side method should be used.

Regards

Flowthermolab SupportTeam

• This reply was modified 2 months, 1 week ago by  MIDHUN MURALI.
• ### Thasiru

Member
February 13, 2024 at 10:15 am

Sir in this given geometry is the periodic boundaries that I have mentioned in the diagram is correct?

• ### MIDHUN

Member
February 13, 2024 at 10:46 am

Hi

Yes its correct.

Regards

M Midhun

• ### Thasiru

Member
February 13, 2024 at 11:52 am

Thanks sir.

When I measure the arc angle sir its shows different angle at different points so which angle should I take as the periodicity angle.

• ### Thasiru

Member
February 17, 2024 at 2:05 pm

Can I know what is the problem here?

• ### Rahul

Member
February 17, 2024 at 5:33 pm

Hi Thasiru,

It seems you are using the wrong rotation axis/direction. You are using (0,0,1) for the rotation axis direction which corresponds to Z axis, when the actual direction should be (0,1,0) or Y axis, from your geometry.

Best regards
Rahul

• ### Thasiru

Member
February 18, 2024 at 10:37 am

Sir, can I know how to find out the direction? Because in space claim, it shows the direction as (0, 0, 1).

• ### Thasiru

Member
February 18, 2024 at 11:24 am

Sir still it shows an error in the parameters.

• ### Rahul

Member
February 18, 2024 at 4:43 pm

Sorry Thasiru, it was a mistake from my end. Yes the axis or rotation is Z-axis. I had just checked it with the axis in the image you had shared and mentioned the axis. Are you using the geometry shared for the assignment in the course or is it from some other source?
Have you tried setting up the periodicity using the automatic method and specifying the periodic sides, instead of the manual method? Is it showing the same issue?
Regards
Rahul

• ### Thasiru

Member
February 19, 2024 at 10:09 am

Yes, sir, I used the geometry given in the course materials, not from an external source. I also applied the automatic method then it shows to use the manual method.

• ### MIDHUN

Member
February 20, 2024 at 8:46 am

Hi Thasiru,

We have also tried with same geometry and periodicity works fine .You need to complete the surface mesh and after completing the surface mesh give update boundaries for the time being you can use wall for the periodic surfaces then after that right the update boundaries tab and set up the periodic boundaries for this case we are also sharing the settings for periodic boundaries.

Regards

Flowthermolab SupportTeam