We perform direct numerical simulations to study the effect of the gravity centre offset in spherical Rayleigh-Benard convection. When the gravity centre is shifted towards the south, we find that the shift of the gravity centre has a pronounced influence on the flow structures. At low Rayleigh number Ra, a steady-state large-scale meridional circulation induced by the baroclinic imbalance, created by the misalignment of the gravity potentials and isotherms, is formed. At high Ra, an energetic jet is created on the northern side of the inner sphere that is directed towards the outer sphere. The large-scale circulation induces a strong co-latitudinal dependence in the local heat flux. Nevertheless, the global heat flux is not affected by the changes in the large-scale flow organization induced by the gravity centre offset.
Wang, G., Santelli, L., Verzicco, R., Lohse, D., Stevens, R. (2022). Off-centre gravity induces large-scale flow patterns in spherical Rayleigh-Bénard convection. JOURNAL OF FLUID MECHANICS, 942 [10.1017/jfm.2022.360].
Off-centre gravity induces large-scale flow patterns in spherical Rayleigh-Bénard convection
Roberto Verzicco;
2022-01-01
Abstract
We perform direct numerical simulations to study the effect of the gravity centre offset in spherical Rayleigh-Benard convection. When the gravity centre is shifted towards the south, we find that the shift of the gravity centre has a pronounced influence on the flow structures. At low Rayleigh number Ra, a steady-state large-scale meridional circulation induced by the baroclinic imbalance, created by the misalignment of the gravity potentials and isotherms, is formed. At high Ra, an energetic jet is created on the northern side of the inner sphere that is directed towards the outer sphere. The large-scale circulation induces a strong co-latitudinal dependence in the local heat flux. Nevertheless, the global heat flux is not affected by the changes in the large-scale flow organization induced by the gravity centre offset.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.