How cn I do Natural Convection?

[Jay Prajapati]

In my model I'm doing plastic extrusion simulation with motion of nozzle simultaneously. So material is flowing continuously and when material comes out of nozzle I want to add convection and conduction.
1)I want to do natural convection with melted material with the air. so how can I do interference melted semi solid part.
2) How to do conduction between glass plate and melted solid?
so how to manage interference of this to surfaces?

 

[FEA way]

The analysis was stopping immediately after it was submitted. I used mass scaling to push it a bit further. Then I noticed that when filament starts moving it can’t pass the edge of the nozzle. It becomes stuck there and because prescribed velocity is still trying to make it move, its elements become severely distorted by unnatural compression. To solve this problem you just have to reduce the filament’s diameter slightly so that it won’t get stuck when trying to enter the nozzle. Because I was working on orphan mesh from imported .inp file, I did it by defining cylindrical coordinate system and editing coordinates of the nodes belonging to the outer surface of the filament. However I assume that you have the geometry of this model and you can make edits directly on it.

However keep in mind that it may still be difficult for the filament to leave the nozzle through its narrow end. You may have to refine the mesh. Otherwise even a single element of filament’s mesh may greatly reduce stable time increment for the whole analysis.

Also check the consistency of all units, just in case.

 

[Jay Prajapati]

Just check this one I ran this one with mass Scaling but still it stops.[URL unfurl="true"]https://res.cloudin[URL unfurl="true"]https://res.cloudinary.com/engineering-com/raw/upload/v1567153836/tips/Explicit_copy_aqzavi.dat[/url]ary.com/engineering-com/raw/upload/v1567153821/tips/Explicit_copy_nk80v8.msg[/url]

 

[FEA way]

Mass scaling itself is not enough to complete this analysis. It was a good move that you changed BCs and simplified the model by deleting the glass part for now. But there are still some issues. I would start from refining the mesh. Also either reduce filament’s diamater or place it already inside the nozzle. Otherwise it will have problems entering the nozzle. Especially with such coarse meshes.

 

[Jay Prajapati]

Its not possible to put Filament inside because I need conduction between Filament and nozzle. I have tried with small distance between nozzle and Glass but when step-2 starts it stops automatically. [URL unfurl="true"]https://res.cloudinary.com/engineering-com/raw/upload/v1567408889/tips/All_Together_x8udot.dat[/url]