Kinetic helicity decay in linearly forced turbulence

The decay of kinetic helicity is studied in numerical models of forced turbulence using either an externally imposed forcing function as an inhomogeneous term in the equations or, alternatively, a term linear in the velocity giving rise to a linear instability. The externally imposed forcing function injects energy at the largest scales, giving rise to a turbulent inertial range with nearly constant energy flux while for linearly forced turbulence the spectral energy is maximum near the dissipation wavenumber. Kinetic helicity is injected once a statistically steady state is reached, but it is found to decay on a turbulent time scale regardless of the nature of the forcing and the value of the Reynolds number (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Oxygen-Rich Cool Stars in the Cepheus Region. New Spectroscopic Observations of Selected Objects from the KP2001 Catalog

Astrophysics - Spectra taken with the 2.6-m telescope at the Byurakan Astrophysical Observatory (BAO) in the λλ4000-7250Å range for eight M giants from the KP2001 catalog confirm...