Local models of stellar convection:

摘要: We study stellar convection using a local three-dimensional MHD model, with which we investigate the influence of rotation and large-scale magnetic fields on turbulent momentum heat transport their role in generating flows zones. The former is studied by computing velocity correlations, known as Reynolds stresses, latter calculating correlation temperature fluctuations, both functions latitude. find that horizontal correlation, Qθφ, capable differential rotation, attains significant values mostly negative southern hemisphere for Coriolis numbers exceeding unity, corresponding to equatorward flux angular momentum. This result also accordance solar observations. radial component Qrφ slow intermediate indicating inward momentum, while rapid occurs outwards. Parametrisation terms mean-field Λ-effect shows qualitative agreement turbulence model Kichatinov & Rudiger (1993) part H ∝ Q θφ cos θ , whereas vertical Λ-effect, V sin only exists. Λ-coefficients become suppressed limit this rotational quenching being stronger occurring slower than H. have behaviour stresses under azimuthal field varying strength. are enhanced presence strengths up above equipartition value, without quenching. Concerning transport, our calculations show direction most efficient at equatorial regions, obtains minimum midlatitudes, slight increase towards poles. latitudinal does not systematic trend function latitude or rotation.