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Vacuum Initial condiction

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Old   March 11, 2010, 08:46
Default Vacuum Initial condiction
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liang liam
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hello, every one
i have a problem

does the Initial condiction can set Vacuum ?


thanks
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Old   March 12, 2010, 01:04
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michael barkhudarov
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voids can be assigned pressure and temperature, but without the use of a bubble model it does not make much difference for one-fluid incompressible flow. What is the application you are using it for?
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Old   March 12, 2010, 03:07
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Quote:
Originally Posted by MuxaB View Post
voids can be assigned pressure and temperature, but without the use of a bubble model it does not make much difference for one-fluid incompressible flow. What is the application you are using it for?

so the voids is air?
I don't know the void means,and how to use it.

i wanna use vapor started into a tube to condensation and I think the tube should not have any fluids at first. so i wanna set the tube as vacuum condiction at first.


thank you very much! you really help me many times!
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Old   April 6, 2010, 10:20
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If you want to inject vapor into a vacuum, then a void model will not work. You will need to use the two-fluid model, with fluid #1 representing liquid phase and fluid #2 representing the vapor. The initial vacuum will have to approximated by the vapor at a low density.

You can then inject vapor (fluid #2) at a mesh boundary by specifying the velocity, density and temperature at it. As it condenses it will form fluid #1, liquid that is..
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Old   April 6, 2010, 10:32
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Quote:
Originally Posted by MuxaB View Post
If you want to inject vapor into a vacuum, then a void model will not work. You will need to use the two-fluid model, with fluid #1 representing liquid phase and fluid #2 representing the vapor. The initial vacuum will have to approximated by the vapor at a low density.

You can then inject vapor (fluid #2) at a mesh boundary by specifying the velocity, density and temperature at it. As it condenses it will form fluid #1, liquid that is..
thank you for your reply!

The initial vacuum will have to approximated by the vapor at a low density. I don't know that means??...
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