Spectral distribution and dissipation of turbulent helicity in rotating channel flow

Abstract

Turbulent helicity is known to be generated in the boundary layer when the system is rotated perpendicular to the wall. In the previous study, we showed that the sign of three terms of the turbulent helicity did not necessarily coincide with that of corresponding dissipation rates near the wall using the LES of rotating channel turbulence. In this study, we discussed this issue by spectral decomposition of the three terms of the turbulent helicity. It was shown that only the high wavenumber component of the spectrum cannot account for the sign of the dissipation rate.