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-   -   PressureTransmissive bc (http://www.cfd-online.com/Forums/openfoam-solving/59493-pressuretransmissive-bc.html)

fedegavo January 30, 2006 04:21

hallo, i've some question abou
 
hallo, i've some question about using pressureTransmissive b.c.

i've alredy read what "pinf" e "linf" mean, but what about "value"? i mean, looking through this forum, someone adds this voice and someone else not..so, what should i do? i think that "value" is the starting value of pressure,right?

now i'm solving with sonicTurbfoam, and i'm using this b.c. to the outlet of my cilinder:
pinf 89000
linf 10000
value uniform 89000

and in this way things seem to have taken the right way.can someone suggest how tu use proprerly this b.c.?

thank you

federico

hjasak January 30, 2006 04:32

This is fine - when the b.c. g
 
This is fine - when the b.c. gets evaluated, it will calculate its own value. In this case, the "value" entry is for post-processing (of the zero directory, which is where I suspect your initial fields are), because the post-processor should not be evaluating the boundary condition for you.

Enjoy,

Hrv

dhebert January 9, 2007 12:10

Hello everyone, Regarding t
 
Hello everyone,

Regarding the pressureTransmissive b.c., is the value pInf an absolute value, or relative to the reference level? I ask because in my pressure field, I set referenceLevel = 1.01e+5. When I set pInf to zero, simulation will not run, and I get an empty error message:
.
.
.

Reading thermophysicalProperties
Selecting thermodynamics package hMixtureThermo<reactingmixture>


--> FOAM FATAL ERROR :

FOAM exiting

.
.

Thanks for your assistance,

David

schmidt_d August 20, 2007 16:33

There is a special check in th
 
There is a special check in the pressureTransmissive BC (and also waveTransmissive) that throws an error if the far-field value is set to zero, saying that this is an "unphysical pInf_ specified". So you must use the absolute pressure.

DPS


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