Learning Forum

[Kin Wing Wong]

In FLUENT meshing, I can generate mesh with a single periodicity condition. When it comes to multiple periodicity, the auto-meshing of the volume mesh gives an error,

Error: Multiple periodicity definitions are detected. You can only perform auto meshing
with a single periodic boundary definition.
Error Object: #f

Is there a workaround to define multiple periodicity to have perfectly mapped mesh on both periodic surfaces?

[Federico Alzamora Previtali]

Hello, 

Multiple periodicity can be enabled by inserting a Custom Journal task in the Watertight geometry workflow. Here's a sample of the commands to enter:

(define source-id 47)
(define target-id 48)
(ti-set-size-field-periodicity "translational" '(0 25 0))
(ti-menu-load-string (format #f "~%/boundary recover-periodic-surfaces translational auto ~a ," source-id))

(define source-id 49)
(define target-id 50)
(ti-set-size-field-periodicity "translational" '(-30 0 -30))
(ti-menu-load-string (format #f "~%/boundary recover-periodic-surfaces translational auto ~a ," source-id))

(enable-feature 'allow-multiple-periodicity)

 

Note that you will need to find the corresponding source/target ids for the corresponding faces in your setup and define the appropriate periodicity. The example above has 2 translational periodicity with vectors (0 25 0) and (-30 0 -30).

I hope this helps!

Federico

[Kin Wing Wong]

Thank you for your reply. May I ask which version of Fluent meshing are you using? When I run the journal for enabling multiple periodcity, it shows me the error of, 

 

Feature allow-multiple-periodicity is not known

 

#f

[Federico Alzamora Previtali]

This feature is supported in 22R2 and up.

[Kin Wing Wong]

Thanks, then I will try again in the new version.