[immortality]

it seems fixedValue isn't stable.when i set a fixed pressure on outlet the neighbor cells become very higher in pressur.it seems this BC isn't so stable.have had other users same experiences?how to overcome the issue?

[ngj]

Good morning Ehsan,

Please, again, do read this thread:

http://www.cfd-online.com/Forums/ope...-get-help.html

The way you approach asking questions is not at all up to standard, and the only way of answering your question would be to guess.

Kind regards

Niels

[immortality]

Hi dear Niels
I wrote that text by cellphone and wanted to add an image to it.thanks that you remembered me!
could you view these images?
the pressures of neighbors have been increased a lot.its a simple case like a forward step.
its a simple box that 1/4 height of its right wall is open(outlet).it has filled by a pressure of 1800000pa and BC is 800000pa.
in the case the whole of right wall is opened didn't such problem occur.
thanks so much.

[immortality]

I set BC to 1550000 pa and it repeats.I don't know its a physical issue or numerical because of fixedValue BC is somewhat unstable.
I have attached more pressure on outlet BC.

[immortality]

I set fixedMean and its the result again.
a jump in pressure in neighbor cells occurs.does it tell that pressure on boundary is low still?
is it true?

opening
    {
        
        type fixedMean;
        meanValue 1550000;
        value uniform 1550000;
    }

has had anyone such experiences?

[immortality]

and for compare and to be complete its a case that all the right wall is open.
as you view no jump in neighbouring of patch cells is observing.
any idea?

[immortality]

I add cases.