Learning Forum

[Dato]

Hi all,

I'm using Lee model in VOF to simulation 2D boiling. And I have pressure dependent saturation temperature set. I learned from Fluent User Guide that pressure-dependency should be specified in terms of absolute pressure. And I know what pressure Fluent use is Gauge pressure.

Here comes the question: How should I specify operating pressure? Should I set it to zero or Fluent would add operating pressure automatically  when calculating saturation temperature? 

Any advice would be highly appreciated!!!!!

[Rob]

It should be handled automatically, but depending on what you're doing you may find setting operating to zero to help with other elements of the model. 

[Dato]

Yes, I found that Fluent would automatically handle and there is no need to set operating pressure to zero. And in my case, I think that density is specified as piecewise-linear temperature dependent so there is no need to specify to zero. 

Hold on, you said that"you may find setting operating to zero to help with other elements of the model. " Do you mean it will help that zero should be set when using the Lee model or the VOF model? I know that in some aero flow cases with high pressure drop, it should be set to zero. 

Thank you sir. 

[Rob]

Correct. As you've not said anything about the system I have no idea what sort of conditions you're modelling.