When resolution matters

Example of the battery seeded dynamo simulations for the solar case at 20 km (top); 10 km (middle) and 5 km (bottom) resolutions. Panels on the left show vertical velocity at the lower chromosphere at 840 km. Panels on the right show the corresponding vertical component of the magnetic field.

 

Convection in different stars

Temperature for horizontal cuts at the mean vertical height of tau = 1 for hydrodynamical snapshots from preliminary runs using grey opacity. The temperatures and gravities for the stars shown (order of increasing horizontal size): 3900 K, 66990 cm/s2 (M0V); 4855 K, 40640 cm/s2 (K0V); 5780 K, 27398 cm/s2 (G2V); 6310 K, 25120 cm/s2 (intermediate spectral type between F3V and G2V). The values of the colour scale of each star are different.

 

Kelvin-Helmhotz instability in 2-fluid Mancha

      

Evolution of the Kelvin-Helmholtz instability in a partially ionized plasma, simulated with Mancha-2F. The top half of the figures displays the density of the charged fluid (ions + electrons) and the bottom half displays the density of the neutral fluid; left panel correspond to the high numerical diffusion and the right panel has low diffusivity.

 

Rayleigh-Taylor instability in 2-fluid Mancha

 

Time evolution of the charged (ions+elñectrons, top) and neutral (bottom) density in the highest-resolution simulations of the Rayleigh-Taylor Instability in a partially ionized plasma, with Mancha-2F. The conditions correspond to a thin prominence thread of partially ionized plasma surrounded by hot corona. The characteristic size of the simulation box L0=1 Mm. Spatial resolution of simulations is 1 km. The magnetic field is strictly perpendicular to the perturbation plane.

   

Same as above, except for the magnetic field direction. Left: The magnetic field is rotated out of the perturbation plane and shared with a characteristic scale of L0/2. Right: The magnetic field is rotated out of the perturbation plane and shared with a characteristic scale of L0.

 

Vorticity channels in simulations of solar magneto-convection by Mancha

 

Vorticity channels associated with the presence of magnetic flux tubes are highlighted in orange. The grey scale image at the bottom indicates temperature below surface. Top: only Ambipolar diffusion is included. Bottom: both Ambipolar diffusion and the Hall effects are included. Notice more frequent appearance of cortices in the simulations with the Hall effect.

 

Solar convection simulated with MANCHA: Quiet Sun

Evolution of the temperature, vertical velocity and magnetic field in the 3D MHD simulation of the solar near-surface convection performed with the MANCHA code (Khomenko et al).

 

2D Convection at F3V star