Abnormal temperature build up and loss in cooling baffle and channel

[RK1097]

As shown in the images below, circuit coolant temperature shows no concern but suddenly there's a huge temperature variation in the circuit metal temperature results in the same baffle.

This has happened quite a few times and I'm yet to understand the causation. Often there's one or two random baffles that exhibit extreme fluctuation in circuit metal temperature. There have been cases where the cooling lines and the entire setup is symmetric 1-to-1 and the abnormal circuit metal temperature shows up on only one side. Is there any explanation for this? I haven't been very successful at getting rid of it.

Baffle diameter: 23.8mm (3 beams)

Baffle height: 45.5mm

Channel diameter: 14.68mm

Coolant Inlet Temperature: 26.7C / 80F

Shortest distance from tip of the baffle to the molded part: 38.7mm / 1.5"

V-Gap between baffle beams: 6.35mm / 0.25"

(For anyone thinking there's a cooling channel right above the baffle in question, please be assured it's on the very back of the part, the perspective makes it look like it's right above it. It is actually no where near the baffle.)

[bernor_mf]

@RK1097 

Hi,
this looks pretty strange to me, indeed.

I assumed you have checked the baffle and runner mesh:
no overlaying beams or short beams in area (at channel - baffle connection).
Sometimes a very small disc like beam element could show up, especially if using "Create centerline" from CAD channels and meshing.

Could you try to model baffle as single line, to see what happens?
This way of modelling where introduced in 2018.2 release, to make modelling easier.
(Also as using "Create centerline" from CAD channels makes it easier to model.)
Bubblers and Baffles : Mesh enhancements for 2018.2

If still issues, I believe Autodesk Tech Support need the study for further investigation,
and also R&D to review what is going on.

Regards,
Berndt

[RK1097]

Hi,

This was forwarded to Autodesk Tech Support and they confirmed that it is a known issue and currently being worked on. The problem occurs due to L:D ratio when there are very short (length) but thick (diameter) baffles. As 2018.2 and up version tries to mesh with minimum 3 beams. In some conditions even 2 beams on a baffle are too close (likely the issue here).

I reran with lower number of beams in the affected area and that solved the issue. The concern is sometimes there are tens if not hundreds of these short baffles in molds that I work with, so manually adjusting each and every single one of them is not very efficient. Autodesk is currently working towards making the mesher smarter in that sense. Hoping to see the new patch address this soon.

Cheers.

[bernor_mf]

Hi,

thank you very much for sharing the findings and information.

Hope to see a resolution of this issue too.

Regards,

Berndt