Implicit large eddy simulations of global solar convection: effects of numerical resolution in non-rotating and rotating cases
arXiv:2208.05738 · doi:10.3847/1538-4357/ac9af3
Abstract
Simulating deep solar convection and its coupled mean-field motions is a formidable challenge where few observational results constrain models that suffer from the non-physical influence of the grid resolution. We present hydrodynamic global Implicit Large-Eddy simulations (ILES) of deep solar convection performed with the EULAG-MHD code, and explore the effects of grid resolution on the properties of rotating and non-rotating convection. The results, based on low-order moments and turbulent spectra reveal that convergence could be achieved in non-rotating simulations provided sufficient resolution in the radial direction. The flow is highly anisotropic, with the energy contained in horizontal divergent motions exceeding by more than three orders of magnitude their radial counterpart. By contrast, in rotating simulations the largest energy is in the toroidal part of the horizontal motions. As the grid resolution increases, the turbulent correlations change in such a way that a solar-like differential rotation, obtained in the simulation with the coarser grid, transitions to the anti-solar differential rotation. The reason for this change is the contribution of the effective viscosity to the balance of the forces driving large-scale flows. As the effective viscosity decreases, the angular momentum balance improves, yet the force balance in the meridional direction lessens, favoring a strong meridional flow that advects angular momentum towards the poles. The results suggest that obtaining the correct distribution of angular momentum may not be a mere issue of numerical resolution. Accounting for additional physics, such as magnetism or the near-surface shear layer, may be necessary in simulating the solar interior.
arXiv comment23 pages, 16 figures, submitted to ApJ
References in corpus (38)
- Turbulent Convection Under the Influence of Rotation: Sustaining a Strong Differential Rotation
- Efficient Spherical Harmonic Transforms aimed at pseudo-spectral numerical simulations
- Structure and Evolution of Giant Cells in Global Models of Solar Convection
- From solar-like to anti-solar differential rotation in cool stars
- Anomalously Weak Solar Convection
- Meridional Circulation in Solar and Stellar Convection Zones
- A simulation of convective dynamo in the solar convective envelope: maintenance of the solar-like differential rotation and emerging flux
- Solar Meridional Circulation from Doppler Shifts of the Fe I line at lambda 5250 Angstroms as Measured by the 150-foot Solar Tower Telescope at the Mt. Wilson Observatory
- Rapidly Rotating Suns and Active Nests of Convection
- Differential rotation in solar-like stars from global simulations
- Magnetically controlled stellar differential rotation near the transition from solar to anti-solar profiles
- High-resolution calculation of the solar global convection with the reduced speed of sound technique: II. Near surface shear layer with the rotation
- Reconciling solar and stellar magnetic cycles with nonlinear dynamo simulations
- Reynolds stress and heat flux in spherical shell convection
- Confirmation of bistable stellar differential rotation profiles
- Gyroscopic Pumping in the Solar Near-Surface Shear Layer
- The Spectral Amplitude of Stellar Convection and its Scaling in the High-Rayleigh-Number Regime
- Helioseismic Imaging of Fast Convective Flows Throughout the Near-Surface Shear Layer
- The Emergence of Solar Supergranulation as a Natural Consequence of Rotationally-Constrained Interior Convection
- High-resolution calculations of the solar global convection with the reduced speed of sound technique: I. The structure of the convection and the magnetic field without the rotation
- Stellar mixing length theory with entropy rain
- Solar differential rotation reproduced with high-resolution simulation
- Generation solar-like differential rotation
- A Comprehensive Method to Measure Solar Meridional Circulation and Center-to-Limb Effect Using Time-Distance Helioseismology
- The Solar Meridional Circulation and Sunspot Cycle Variability
- Supergranulation as the largest buoyantly driven convective scale of the Sun
- What sets the magnetic field strength and cycle period in solar-type stars?
- Understanding solar torsional oscillations from global dynamo models
- Helioseismology challenges models of solar convection
- Modelling turbulent stellar convection zones: sub-grid scales effects
- Supergranulation and multiscale flows in the solar photosphere: Global observations vs. a theory of anisotropic turbulent convection
- Hydrodynamic Properties of the Sun's Giant Cellular Flows
- Realistic modeling of local dynamo processes on the Sun
- Meridional Circulation Dynamics in a Cyclic Convective Dynamo
- Breaking Taylor-Proudman balance by magnetic field in stellar convection zone
- Spatial Scales and Time Variation of Solar Subsurface Convection
- Forward Modeling Helioseismic Signatures of One- and Two-cell Meridional Circulation
- Numerical convergence of 2D solar convection in implicit large-eddy simulations