Greetings fellow members,
I’m implementing a DG scheme for a Poiseuille flow in Freefem. While I get very satisfying results on the velocity, I’m surprised with negative values for the pressure. Anyone had a similar issue ?
Best regards.
Expected pressure :
My result :
Because generally the pressure is defined through a constant, so the solve this problem we impose the nulle mean value of the pressure .
Thank you sir for the reply, it makes perfect sense.
Any idea how to retrieve the ‘physically acceptable’ values ? I tried adding a penalization term of the form intalledges of alpha*jump(p)*jump(q), but no success…
Best regards !
Is your problem an incompressible NS equation? then the pressure is the hydrodynamic pressure and it could be negative (it is only the relative pressure to a constant), and I think you could just add any constant to make sense
I see now.
I just wanted for it to make more sense on its own, without forcing a constant to add or by stabilizing the scheme with a term…
Thank you sir !