Atmospheric boundary layers: Coriolis force in the tutorials
 

Hi,


I'm trying to make sense of the atmospheric boundary condition tutorials. In the last couple of releases (v2206 as of now) there have been two main tutorial cases for atmospheric boundary layer runs: atmFlatTerrain (with Leipzig data for validation) and atmForestStability (Ryningsnäs data).

I wasn't able to grok what is going on with the Coriolis term in the relevant fvOptions files:

• atmFlatTerrain: https://develop.openfoam.com/Develop...tant/fvOptions
• atmForestStability: https://develop.openfoam.com/Develop...tant/fvOptions

The values for the Coriolis source Omega (the rotation vector) are exactly the same in both cases, although the two tutorial cases refer to different experimental datasets (Leipzig at about 53° latitude, and Ryningsnäs at about 57°). Different latitudes should give different vector magnitudes.



In addition, both cases seem to assume a geostrophic wind of 17.5 m/s, giving the same pressure gradient. The 17.5 value is documented in the Leipzig case, but not really for any Ryningsnäs data I was able to find.


Is there anything I am misunderstanding, or is this an oversight of some type?



Best regards

I think sin(53) is almost the same with sin(57). So you can use 57 but the results would not differ a lot.

The pressure gradient partly comes from velocity. It is calculated by 2*omega*U. Its not like the pressure gradient in fully developed flow which can be cauclated from tau_w.