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Boundary conditions when simulating injection molding

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Old   April 1, 2010, 10:26
Default Boundary conditions when simulating injection molding
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Jonathan Skovhus
Join Date: Feb 2010
Location: Aalborg
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I am currently trying to simulate a mold filling using the interFoam solver as basis. But I do not quite understand how to implement the right boundary conditions.

My biggest problem is that I don't know how to make a boundary conditions that allows the air to escape, while the polymer is still trapped inside the cavity. Does anyone have any ideas on how to solve this?

This is what I have achieved so far:
http://www.postimage.org/image.php?v=TsOiN_9

Furthermore the time to fill the mold seems to be taking to long. I am currently using these boundary conditions (Notice that I have two outlets for the air to escape):

My U-file:
dimensions [0 1 -1 0 0 0 0];

internalField uniform (0 0 0);

boundaryField
{
inlet
{
type fixedValue;
value uniform (0 0 -40);
}
outlet1
{
type zeroGradient;
}
outlet2
{
type zeroGradient;
}
patch6
{
type fixedValue;
value uniform (0 0 0);
}.....

My p-file:
dimensions [1 -1 -2 0 0 0 0];

internalField uniform 0;

boundaryField
{
inlet
{
type fixedValue;
value uniform 0;
}
outlet2
{
type fixedValue;
value uniform 0;
}
outlet1
{
type fixedValue;
value uniform 0;
}
patch6
{
type zeroGradient;
}....

My alpha-file:
dimensions [0 0 0 0 0 0 0];

internalField uniform 0;

boundaryField
{
inlet
{
type inletOutlet;
inletValue uniform 1;
value uniform 1;
}
outlet1
{
type zeroGradient;
}
outlet2
{
type zeroGradient;
}
patch0
{
type zeroGradient;
}
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Old   April 6, 2010, 06:25
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mediode
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maybe this might be helpfull:

Injection of a fluid into a cavity

Cheers
m*
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Old   April 6, 2010, 09:22
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Jonathan Skovhus
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I have already know that thread. Unfortunately I do not see that any real solution is presented in that thread. But the idea of treating all boundaries as outlets and once the fluid reaches the boundary then switch it to a wall boundary seems to be a good idea. However I don't really have any idea on how to implement this - does anyone know how to do this???
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filling, injection, mold, molding, polymer

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