Learning Forum

[Ermanno Manca]

Hello, I need to run a simulation in a vacuum.

I'm not sure and I couldn't encounter any information regarding the empty (not defined) space between components and environment in ANSYS Fluent. 

Is the standard environment and consequently also the empty space between components air in ANSYS Fluent? And if so, where can I change these characteristics? I need to be sure that there is no convection and only surface to surface radiation in my simulation.

I'm using ANSYS Fluent 2023 R1. 

 

Thank you so much and best regards

Ermanno

[SRP]

Hi,

Vacuum is a space that is empty of matter.  The mean free path of residual gases is longer than the size of the chamber or of the object under test. At such low pressure values the Knudsen number would be large making the continuum approach invalid. So theoretically it will not be possible to model vacuum in Fluent as this is based on a continuum approach.

Thank you.

[Ermanno Manca]

Hi,

thank you so much for your reply. Is it possible to do this in ANSYS CFX? 

Otherwise would it be possible with a little workaorund e.g. creating a sphere around the model that fills all empty spaces and adapting the material in CFX close to a vacuum?