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Pressure wave in oil

Ametra Expression Numérique

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Hi all !

I'm actually trying to compute a pressure wave in a box full of oil. This overpressure is due to a local boiling.
As a start, I try with a simple cube in a bigger one. The pressure source is on a face of the small cube and time dependent.
I'm using the Incompressible Navier-Stokes equation, but I'm wondering if it's the right equation... What about acoustics, certainly better adapted to wave propagation.

Thanks in advance.

MD

1 Reply Last Post May 6, 2010, 6:11 AM EDT

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Posted: 10 years ago May 6, 2010, 6:11 AM EDT
well it depends of the specifics of your problem..
what is the size of the box, the soundspeed in oil and the time scale of your local boiling event ?
comparing these 3 numberswill tell you how to model it. if the pressure rise is faster than the transit time in the box, you should use accoustic that provide you linearized wave [ small amplitude] otherwise you can use quasistatic approximation and just use oil EOS . you dont need comsol then.
There is no wave propagation in incompressible NS anyway.

JF
well it depends of the specifics of your problem.. what is the size of the box, the soundspeed in oil and the time scale of your local boiling event ? comparing these 3 numberswill tell you how to model it. if the pressure rise is faster than the transit time in the box, you should use accoustic that provide you linearized wave [ small amplitude] otherwise you can use quasistatic approximation and just use oil EOS . you dont need comsol then. There is no wave propagation in incompressible NS anyway. JF

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