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Only velocity is shown as a result in Transitional Flow , can i show pressure ?

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Hello everyone

I have ran a transitional flow simualtion ( simple 2D Cube) and i can only see the results for the pressure map. Could someone please kindly explain how i plot other variables (pressure) , when i add new plots there seems to be no data to add.

Thanks in advance Rhys



1 Reply Last Post Nov 25, 2020, 10:21 a.m. EST
Christopher Boucher COMSOL Employee

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Posted: 3 years ago Nov 25, 2020, 10:21 a.m. EST

Hi Rhys,

The variable for pressure is not defined in domains for the Transitional Flow or Free Molecular Flow interface. At high Knudsen number (very low gas density) the concept of pressure as a scalar quantity throughout the domain is not valid anymore, because the gas molecule velocities at a point in space can't be assumed to follow a local Maxwellian distribution.

Chris

Hi Rhys, The variable for pressure is not defined in domains for the Transitional Flow or Free Molecular Flow interface. At high Knudsen number (very low gas density) the concept of pressure as a scalar quantity throughout the domain is not valid anymore, because the gas molecule velocities at a point in space can't be assumed to follow a local Maxwellian distribution. Chris

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