Magnus: A New Resistive MHD Code with Heat Flow Terms

Navarro, Anamaría; Lora-Clavijo, F. D.; González, Guillermo

doi:10.3847/1538-4357/aa7a13

Cited by 9 publications

(6 citation statements)

References 75 publications

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“…A 2D test designed to evaluate the anisotropic heat conduction along oblique magnetic field lines was initially proposed by Jiang et al (2012) and reproduced by Navarro et al (2017). The initial data consists of a small hot rectangular "plate" at the bottom of the domain.…”

Section: D Hot Plate Testmentioning

confidence: 99%

Modeling the thermal conduction in the solar atmosphere with the code MANCHA3D

Navarro

Khomenko

Modestov

et al. 2022

A&A

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Context. Thermal conductivity is one of the important mechanisms of heat transfer in the solar corona. Within the limit of strongly magnetized plasma, it is typically modeled by Spitzer's expression, where the heat flux is aligned with the magnetic field. Aims. This paper describes the implementation of heat conduction into the MANCHA3D code, with an aim of extending single-fluid magnetohydrodynamic (MHD) simulations from the upper convection zone into the solar corona. Methods. Two different schemes for modeling heat conduction are implemented in this work: (1) a standard scheme where a parabolic term is added to the energy equation and (2) a scheme where the hyperbolic heat flux equation is solved. Results. The first scheme limits the time step due to the explicit integration of a parabolic term, which makes the simulations computationally expensive. The second scheme solves the limitations on the time step by artificially limiting the heat conduction speed to computationally manageable values. The validation of both schemes was carried out with standard tests in one, two, and three spatial dimensions. Furthermore, we implemented the model for heat flux derived by Braginskii (1965) in its most general form, where the expression for the heat flux depends on the ratio of the collisional to cyclotron frequencies of the plasma and, therefore, on the magnetic field strength. Additionally, our implementation takes into account the heat conduction in parallel, perpendicular, and transverse directions, and provides the contributions from ions and electrons separately. The model recovers Spitzer's expression for parallel thermal conductivity within the strongly magnetized limit but also transitions smoothly between field-aligned conductivity and isotropic conductivity for regions with a low or null magnetic field. We describe the details of the implementation of Braginskii's thermal conductivity using a combination of the first scheme for the perpendicular and transverse directions and the second scheme for the parallel component. Furthermore, we estimated the thermal conductivities in a quiet-Sun model. In this model, we find that the perpendicular and transverse components for electrons and ions and the parallel component for ions might have some significance below the transition region. Above the transition region only the parallel component for ions might be important. Finally, we present a 2D test for heat conduction using realistic values of the solar atmosphere where we prove the robustness of the two schemes implemented and show that our adaptation of the hyperbolic treatment offers a great advantage over the computational cost of the simulations.

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Section: D Hot Plate Testmentioning

confidence: 99%

Modeling the thermal conduction in the solar atmosphere with the code MANCHA3D

Navarro

Khomenko

Modestov

et al. 2022

A&A

View full text Add to dashboard Cite

show abstract

“…The equations are solved with the MAGNUS code (Navarro et al 2017) in a simulation box of uniform grid with a 5 km resolution in both 𝑥− and 𝑧−directions which covers the region of [−5.0, 5.0] × [1.8, 11.8] Mm 2 . The Courant-Friedrichs-Lewy (CFL) number is set to 0.1, a small number in order to obtain a small time step to solve the elliptic term introduced by the thermal conduction, and an adaptive time step.…”

Section: Simulation Box and Boundary Conditionsmentioning

confidence: 99%

“…In this paper we simulate the ejection of a tadpole jet generated in the chromosphere and study the influence of the thermal conduction and the magnetic field amplitude on its dynamic. The numerical simulations are carried out with the MAGNUS code (Navarro et al 2017) and the model of the gas pressure driver is taken from the work of Srivastava et al (2018). The magnetic field modelled corresponds to a flux tube and the temperature is taken from the semi-empiric profile of Avrett & Loeser (2008).…”

Section: Introductionmentioning

confidence: 99%

Thermal conduction effects on formation of chromospheric solar tadpole-like jets

Navarro

Lora-Clavijo

Murawski

et al. 2020

Monthly Notices of the Royal Astronomical Society

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We measure the effects of non-isotropic thermal conduction on generation of solar chromospheric jets through numerical simulations carried out with the use of one fluid MHD code MAGNUS. Following the work of Srivastava et al. (2018), we consider the atmospheric state with a realistic temperature model and generate the ejection of plasma through a gas pressure driver operating in the top chromosphere. We consider the magnetic field mimicking a flux tube and perform parametric studies by varying the magnetic field strength and the amplitude of the driver. We find that in the case of thermal conduction the triggered jets exhibit a considerably larger energy and mass fluxes and their shapes are more collimated and penetrate more the solar corona than for the ideal MHD equations. Low magnetic fields allow these jets to be more energetic, and larger magnetic fields decrease the enhancement of mass and energy due to the inclusion of the thermal conductivity.

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“…A two-dimensional test designed to evaluate the anisotropic heat conduction along oblique magnetic field lines was proposed by Jiang et al ( 2012) and reproduced by Navarro et al (2017). The initial data consists of a small hot rectangular "plate" at the bottom of the domain.…”

Section: Two-dimensional Hot Plate Testmentioning

confidence: 99%

Modeling the thermal conduction in the solar atmosphere with the code MANCHA3D

Navarro,

Khomenko,

Modestov

et al. 2022

Preprint

Self Cite

View full text Add to dashboard Cite

Context. Thermal conductivity is one of the important mechanisms of heat transfer in the solar corona. In the limit of strongly magnetized plasma, it is typically modeled by Spitzer's expression where the heat flux is aligned with the magnetic field. Aims. This paper describes the implementation of the heat conduction into the code MANCHA3D with an aim of extending singlefluid MHD simulations from the upper convection zone into the solar corona. Methods. Two different schemes to model heat conduction are implemented: (1) a standard scheme where a parabolic term is added to the energy equation, and (2) a scheme where the hyperbolic heat flux equation is solved. Results. The first scheme limits the time step due to the explicit integration of a parabolic term, which makes the simulations computationally expensive. The second scheme solves the limitations on the time step by artificially limiting the heat conduction speed to computationally manageable values. The validation of both schemes is carried out with standard tests in one, two, and three spatial dimensions. Furthermore, we implement the model for heat flux derived by Braginskii (1965) in its most general form, when the expression for the heat flux depends on the ratio of the collisional to cyclotron frequencies of the plasma, and, therefore on the magnetic field strength. Additionally, our implementation takes into account the heat conduction in parallel, perpendicular, and transverse directions, and provides the contributions from ions and electrons separately. The model recovers Spitzer's expression for parallel thermal conductivity in the strongly magnetized limit but also transitions smoothly between field-aligned conductivity and isotropic conductivity for regions with a low or null magnetic field. We describe the details of the implementation of Braginskii's thermal conductivity using a combination of the first scheme for the perpendicular and transverse directions and the second scheme for the parallel component. We estimate thermal conductivities in a quiet-Sun model. In this model, we find that the perpendicular and transverse components for electrons and ions and the parallel component for ions might have some significance below the transition region. Above the transition region only the parallel component for ions might be important. Finally, we present a two-dimensional test for heat conduction using realistic values of the solar atmosphere where we prove the robustness of the two schemes implemented and show that our adaptation of the hyperbolic treatment offers a great advantage over the computational cost of the simulations.

show abstract

Magnus: A New Resistive MHD Code with Heat Flow Terms

Cited by 9 publications

References 75 publications

Modeling the thermal conduction in the solar atmosphere with the code MANCHA3D

Modeling the thermal conduction in the solar atmosphere with the code MANCHA3D

Thermal conduction effects on formation of chromospheric solar tadpole-like jets

Modeling the thermal conduction in the solar atmosphere with the code MANCHA3D

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