Surface area of each cell for mean beam length calculation
 

Dear OpenFOAM users:

I am attempting to calculate the mean beam length of each cell on a finite volume mesh on OpenFOAM (a desired length scale for radiation calculations). I am using the relationship L=3.6V/A where L is the mean beam length, V is the volume of the cell, and A is the surface area of the cell.

I know that there is a utility that easily calculates the volume of each cell (writeCellVolumes). Is there a similar utility that will calculate the surface area of each cell and output a scalar field called cArea or something similar?

I know that there is already a utility that calculates the area for all internal faces, but the one that I found does not say which area corresponds to which face. I also know there is mesh.Sf, but to my understanding this only includes internal faces as well.

Any help would be appreciated!