Helical turbulence prevails over inertial waves in forced rotating flows at high Reynolds and low Rossby numbers

The forcing function is a fully helical flow that can also be viewed as mimicking the effect of atmospheric convective motions. We test in the helical case variants of a model developed previously (Baerenzung et al. (2008b)) against direct numerical simulations (DNS), using data from a run on a grid of 1536³ points; we also contrast its efficiency against a spectral Large Eddy Simulation (LES) (Chollet and Lesieur (1981)) as well as an under-resolved DNS.

The model including the contribution of helicity to the spectral eddy dissipation and eddy noise behaves best, allowing us to recover statistical features of the flow. We recall that even if the model is based on isotropic assumptions, we show in a previous study (Baerenzung et al. (2010)) that the small scales of flows at moderate Rossby number can be considered to be isotropic in the range of parameters considered here, and that, therefore, our model is appropriate to treat this kind of flow.