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pressure in interFoam

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Old   June 24, 2023, 06:36
Default pressure in interFoam
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interFoam is a solver for 2 incompressible, isothermal immiscible fluids using a VOFmethod.

The pressure is defined as:


Code:
dimensions      [1 -1 -2 0 0 0 0]
Instead of the kinematic pressure seen in incompressible solvers:


Code:
dimensions      [0 2 -2 0 0 0 0];
In the damBreak tutorial, the pressure has a uniform value of 0. When I run the case I get negative values [-11]. What does this mean? -11 Pa in relation to atm pressure?
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Old   June 26, 2023, 11:04
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Greetings,

interFoam works with a p_rgh, which includes the hydrostatic contribution,
so p_rgh = p - rho*gh;

Altough i didnt understand your question, but hope this helps.
Bests,
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Old   June 26, 2023, 11:12
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Quote:
Originally Posted by amirhosseintaran View Post
Greetings,

interFoam works with a p_rgh, which includes the hydrostatic contribution,
so p_rgh = p - rho*gh;

Altough i didnt understand your question, but hope this helps.
Bests,
If you run the dambreak tutorial you will see negative values of p_rgh. What does it mean? -x Pa bellow some reference value?
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Old   June 26, 2023, 12:19
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Quote:
Originally Posted by newGuyAtCFD View Post
If you run the dambreak tutorial you will see negative values of p_rgh. What does it mean?
It means that the value of p_rgh is less than zero! You can manipulate the value of p_rgh (eg make it positive, or make it equal the static pressure at a certain location) by simply choosing a different reference height, hRef.
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Old   June 27, 2023, 03:14
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I think interFoam needs p_rgh to take the hydrostatic effetcs into account, but it does not need "realistic" values for the pressure, simply gradients. I may be wrong though!
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