Precursor method for LES: timeVaryingMappedFixedValue
 

Hi Foamers,
I would like to use a precursor method to develop an atmospheric turbulent boundary layer for LES calculations. I will use cyclic boundary conditions for my precursor domain, but I have still some misunderstanding:

1/ I will use timeVaryingMappedFixedValue for U in my second domain. What about the pressure? I am reading that I should use zeroGradient, but I don't see why I mustn't use also timeVaryingMappedFixedValue ?

2/ If I use a fixedValue for p-inlet as well as for U-inlet, what about my BC in the outlet? Can I specify both zeroGradient for U and p in the outlet ?

3/ My data has to be in constant/boundaryData/inletPatch/... How to generate them from my precursor domain? I am thinking of using a function is my controlDict, such as "cuttingPlane", "sampledPatch" or "surfaces" , but I don't know which one to prefer (for performance) and which format to use (in order to have direclty the input format for timeVaryingMappedFixedValue .)

Any help would be really appreciated.