2012/11/30 by Rakesh K. Yadav, Thomas Gastine, T. Gastine +1
Biochemistry, Genetics and Molecular Biology · Earth and Planetary Sciences · Mathematics · Physics and Astronomy · #Boundary value problem #Classical mechanics #Dipole #Dynamo #Dynamo theory #Geology and Paleoclimatology Research #Geomagnetism and Paleomagnetism Studies #Geometry #Magnetic field #Materials science #Mathematics #Mechanics #Physics #Scaling #Shell (structure) #Slip (aerodynamics) #Solar and Space Plasma Dynamics #Spherical shell #Thermodynamics #Vector field #astro-ph.EP #astro-ph.SR #physics.geo-ph
paper · pdf · doi:10.1016/j.icarus.2013.02.030
10 pages, 9 figures, 1 table. To appear in ICARUS
arxiv created 2013/02/20 · openalex publication_date 2013/04/03 · arxiv updated 2015/06/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Numerical simulations of convection driven rotating spherical shell dynamos have often been performed with rigid boundary conditions, as is appropriate for the metallic cores of terrestrial planets. Free-slip boundaries are more appropriate for dynamos in other astrophysical objects, such as gas-giants or stars. Using a set of 57 direct numerical simulations, we investigate the effect of free-slip boundary conditions on the scaling properties of heat flow, flow velocity and magnetic field strength and compare it with earlier results for rigid boundaries. We find that the nature of the mechanical boundary condition has only a minor influence on the scaling laws. We also find that although dipolar and multipolar dynamos exhibit approximately the same scaling exponents, there is an offset in the scaling pre-factors for velocity and magnetic field strength. We argue that the offset can be attributed to the differences in the zonal flow contribution between dipolar and multipolar dynamos.