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]

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]

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]

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