CFD Online Discussion Forums - MappedField BC for Velocity in LES

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MappedField BC for Velocity in LES

Greetings All

I am trying to set a mappedField B.C. for my fuel inlet according to this tutorial:

$FOAM_TUTORIALS/incompressible/pisofoam/les/pitzDailyMapped

In the blockMeshDict file of this tutorial we have:

inlet
{
type mappedPatch;
offset ( 0.0495 0 0 );
sampleRegion region0;
sampleMode nearestCell;
samplePatch none;

faces
(
(0 22 23 1)
(1 23 24 2)
(2 24 25 3)
);
}

My question is what is this offset? and how should I set it?
Cause I did the same as this tutorial for my LES case and I got this error:

Code:

Selecting turbulence model type LESModel

Selecting LES turbulence model Smagorinsky





--> FOAM FATAL ERROR: 

Case is not 3D or 2D, LES is not applicable



    From function cubeRootVolDelta::calcDelta()

    in file cubeRootVolDelta/cubeRootVolDelta.C at line 72.



FOAM exiting

I think it must be from this parameter,

A short question: Do I need to modify other 0 folder files (except velocity) for setting this B.C.?

Any hint is appreciated.:):)

Regards
Bobi

Dear Bobi
1- does your case run with out another BC?
2- mappedPatch BC maps field from inside domain to patch, the offset here shows the distance from the region (those sample faces you mentioned)

Greetings Nima

There was a problem with my mesh that reported the mentioned error. I solved it.:)

However, I was still wandering about offset parameter.

Have you ever tried to investigate this parameter?
I mean how far this spatial point should be from the injection plane? ( my origin plane)? Can we correlate it with injection radius of fuel flow in domain ?

Regards
Bobi

i have no idea, i feel it depends on your simulation and it varies from one simulation to other