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.
2022
Pubblicato
Rilevanza internazionale
Articolo
Esperti anonimi
Settore ING-IND/06 - FLUIDODINAMICA
English
Benard convection
turbulent convection
plumes/thermals
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].
Wang, G; Santelli, L; Verzicco, R; Lohse, D; Stevens, Rjam
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/315665
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