Hi,
When i run cool analysis for my part, my analysis got failed stating that cool analysis has not converged . I have used 3D mesh for my part. My analysis completed for another iteration for coolant velocity of 10lit/min for same part. But when i increased the coolant velocity to 189lit/min it didnt failed.
What is the reason for this ?
Thnaks in advance
sorry when i increased the coolant velocity to 189lit/min. the cool analysis got failed
Hi,
going from 10 l/min to 189 l/min is a hughe change.
The high flow rate can cause very high circuit pressure drop and Reynolds number,
maybe unrealistic from what a pump can provide it terms of pressure.
To really understand why a convergence issues, the circuit design needs to be understood.
Basically, the Reynolds number should be greater than 4,000 for lines actively involved in cooling the part
to ensure there is turbulent flow within the circuits and hence efficient cooling.
The ideal Reynolds number to achieve is 10,000.
Higher will increase pumping expenses, cost more energy, and a small marginal improvement in heat transfer.
See:
ASMA Help > User's Guide > Modeling > Cooling system > Cooling considerations
ASMA Help > User's Guide > Modeling > Cooling system > Cooling considerations > Heat transfer due to coolant flow
ASMA Help > User's Guide > Modeling > Cooling system > Cooling considerations > Effective heat extraction
For further investigation please contact Autodesk Technical Support at subscription center:
http://subscription.autodesk.com/
And attach your study file and original cad geometry for further investigation.
Regards,
Berndt
Hi,
on a test study using 10 l/min then changed to 189 l/min (and T'inlet=25C) on cooling circuits the analysis converged.
Flow rate : Reynolds number : Pressure drop
10 l/min : 29522 : 32kPa (0.32bar)
189 l/min : 557970 : 10780kPa (107.80bar) [unrealistic high]
What you see is study related.
Why it does not converge is difficult to say without investigating/troubleshooting the study.
For further investigation please contact Autodesk Technical Support at subscription center:
http://subscription.autodesk.com/
And attach your study file and original cad geometry for further investigation.
Regards,
Berndt
I think the water evaporates at this high velocity and temperature. So this might be the reason it cant solve
Hi,
I tested on a part 155 mm in length, T'inlet 99C, channel diameter 8 mm.
Material: Generic PP, and Dual Domain mesh, and it converges.
Which material do you use?
Mold and melt temperatures?
Set or automatic cooling time?
Regards,
Berndt
Hi,
the rule of thumb is to have a cooling inlet temperature 10-20C below wished mold surface temperature as inlet starting point.
So if your mold temperature aim is 99C, try to start at 79-89C of inlet temperature.
Regards,
Berndt
Hi
I tried with coolant inlet temp. at 75 C and at 85C, even for that cool analysis didnt converge
Hi,
thank you for the update.
Why it does not converge is difficult to say without see how it is modeled and for further investigating/troubleshooting of the study.
For further investigation please contact Autodesk Technical Support at subscription center:
http://subscription.autodesk.com/
And attach your study file and original cad geometry for further investigation.
Thank you.
Regards,
Berndt
Hi Mayur,
thank you for the suggestion.
It might well solve such an issue similar to this.
Just some comments:
The suggested option is available in Moldflow Synergy/Insight.
The option to change solver setting is not available in Moldflow Adviser though.
Further, Moldflow Adviser use Cool, and does currently not support Cool FEM
Hope this clarifies.
Regards,
Berndt
Hi Mayur,
I did enable "High analysis resolution" before my analysis
Regards
Dinesh Kumar
Hi,
the High Analysis Resolution (in release 2014 and previous),
and Analysis Model Processing Resolution and Levels 0 - 3 (release 2015).
This is basically for mesh refinement, when having a lot of small features.
It does not affect the solver settings as such.
Refining the mesh in this case would probably not solve the issue, as it seems to be process settings and model related to this study.
Regards,
Berndt