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why fixedValue pressure makes neighbor cells incorrect values |
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June 30, 2013, 04:04 |
why fixedValue pressure makes neighbor cells incorrect values
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#1 |
Senior Member
Ehsan
Join Date: Oct 2012
Location: Iran
Posts: 2,208
Rep Power: 26 |
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?
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Injustice Anywhere is a Threat for Justice Everywhere.Martin Luther King. To Be or Not To Be,Thats the Question! The Only Stupid Question Is the One that Goes Unasked. |
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June 30, 2013, 04:40 |
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#2 |
Senior Member
Niels Gjoel Jacobsen
Join Date: Mar 2009
Location: Copenhagen, Denmark
Posts: 1,901
Rep Power: 37 |
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 |
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June 30, 2013, 04:57 |
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#3 |
Senior Member
Ehsan
Join Date: Oct 2012
Location: Iran
Posts: 2,208
Rep Power: 26 |
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.
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Injustice Anywhere is a Threat for Justice Everywhere.Martin Luther King. To Be or Not To Be,Thats the Question! The Only Stupid Question Is the One that Goes Unasked. |
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June 30, 2013, 05:20 |
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#4 |
Senior Member
Ehsan
Join Date: Oct 2012
Location: Iran
Posts: 2,208
Rep Power: 26 |
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.
__________________
Injustice Anywhere is a Threat for Justice Everywhere.Martin Luther King. To Be or Not To Be,Thats the Question! The Only Stupid Question Is the One that Goes Unasked. |
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June 30, 2013, 05:41 |
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#5 |
Senior Member
Ehsan
Join Date: Oct 2012
Location: Iran
Posts: 2,208
Rep Power: 26 |
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? Code:
opening { type fixedMean; meanValue 1550000; value uniform 1550000; }
__________________
Injustice Anywhere is a Threat for Justice Everywhere.Martin Luther King. To Be or Not To Be,Thats the Question! The Only Stupid Question Is the One that Goes Unasked. |
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June 30, 2013, 05:55 |
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#6 |
Senior Member
Ehsan
Join Date: Oct 2012
Location: Iran
Posts: 2,208
Rep Power: 26 |
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?
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Injustice Anywhere is a Threat for Justice Everywhere.Martin Luther King. To Be or Not To Be,Thats the Question! The Only Stupid Question Is the One that Goes Unasked. |
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July 1, 2013, 11:41 |
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#7 |
Senior Member
Ehsan
Join Date: Oct 2012
Location: Iran
Posts: 2,208
Rep Power: 26 |
I add cases.
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Injustice Anywhere is a Threat for Justice Everywhere.Martin Luther King. To Be or Not To Be,Thats the Question! The Only Stupid Question Is the One that Goes Unasked. |
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