Extended fluid models: Pressure tensor effects and equilibria

Cerri, Silvio Sergio; Henri, Pierre; Califano, Francesco; Sarto, D. Del; Faganello, Matteo; Пегораро, Ф.

doi:10.1063/1.4828981

Cited by 33 publications

(135 citation statements)

References 32 publications

Supporting

Mentioning

132

Contrasting

Order By: Relevance

“…Note in the right panel the generation of a temperature anisotropy: T x < T y corresponding to the bottom layer Ω · B < 0. The agyrotropy leads to the modification of the full pressure tensor 35 which is properly included only in the kinetic models. It is unclear whether this behavior affects significantly the evolution of the instability.…”

Section: A Initial Kinetic Relaxationmentioning

confidence: 99%

Nonlinear evolution of the magnetized Kelvin-Helmholtz instability: From fluid to kinetic modeling

et al. 2013

Self Cite

View full text Add to dashboard Cite

The nonlinear evolution of collisionless plasmas is typically a multi-scale process where the energy is injected at large, fluid scales and dissipated at small, kinetic scales. Accurately modelling the global evolution requires to take into account the main micro-scale physical processes of interest. This is why comparison of different plasma models is today an imperative task aiming at understanding cross-scale processes in plasmas. We report here the first comparative study of the evolution of a magnetized shear flow, through a variety of different plasma models by using magnetohydrodynamic, Hall-MHD, two-fluid, hybrid kinetic and full kinetic codes. Kinetic relaxation effects are discussed to emphasize the need for kinetic equilibriums to study the dynamics of collisionless plasmas in non trivial configurations. Discrepancies between models are studied both in the linear and in the nonlinear regime of the magnetized Kelvin-Helmholtz instability, to highlight the effects of small scale processes on the nonlinear evolution of collisionless plasmas. We illustrate how the evolution of a magnetized shear flow depends on the relative orientation of the fluid vorticity with respect to the magnetic field direction during the linear evolution when kinetic effects are taken into account. Even if we found that small scale processes differ between the different models, we show that the feedback from small, kinetic scales to large, fluid scales is negligable in the nonlinear regime. This study show that the kinetic modeling validates the use of a fluid approach at large scales, which encourages the development and use of fluid codes to study the nonlinear evolution of magnetized fluid flows, even in the colisionless regime.

show abstract

Section: A Initial Kinetic Relaxationmentioning

confidence: 99%

Nonlinear evolution of the magnetized Kelvin-Helmholtz instability: From fluid to kinetic modeling

et al. 2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…Finally Π (1) i is the first order ion gyroviscosity tensor with components Π (1) i,lm as given in Ref. [25]. In the following we present 2D simulations of the KHI in the limit of a relatively strong magnetic guide field with B Be z .…”

Section: Model Equationsmentioning

confidence: 99%

“…[25] in which the plasma is assumed to be made of two distinct, collisionless fluids, ions and electrons (indices e and i, respectively) interacting through the electromagnetic fields. In this model we assume quasi neutrality, n e n i = n, and massless electrons.…”

Section: Model Equationsmentioning

confidence: 99%

“…The gyrotropic components of the pressure tensor are evolved in time (see Appendix A in Ref. [25] for details) while the FLR terms are determined according to Ref. [25].…”

Section: Model Equationsmentioning

confidence: 99%

“…[25] allowing for the inclusion of two distinct scalar pressures, p and p ⊥ , one along the magnetic field and the other perpendicular to it, respectively, as well as for the inclusion at first order of the so-called Finite Larmor Radius (FLR) effects. This approach allow us to include a very important feature in the plasma dynamics i.e., the development of pressure anisotropy driven in this case by the non-linear evolution of KH vortices.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Pressure anisotropy generation in a magnetized plasma configuration with a shear flow velocity

Camillis

Cerri

Califano

et al. 2016

Plasma Phys. Control. Fusion

View full text Add to dashboard Cite

The nonlinear evolution of the Kelvin Helmholtz instability in a magnetized plasma with a perpendicular flow close to, or in, the supermagnetosonic regime can produce a significant parallel-toperpendicular pressure anisotropy. This anisotropy, localized inside the flow shear region, can make the configuration unstable either to the mirror or to the firehose instability and, in general, can affect the development of the KHI. The interface between the solar wind and the Earth's magnetospheric plasma at the magnetospheric equatorial flanks provides a relevant setting for the development of this complex nonlinear dynamics.

show abstract

The impact of a hot sodium ion population on the growth of the Kelvin‐Helmholtz instability in Mercury's magnetotail

2015

View full text Add to dashboard Cite

Observations of Mercury's local plasma environment by MErcury Surface, Space ENvironment, GEochemistry, and Ranging have revealed that the planet hosts a strongly asymmetric magnetosphere as a result of an off‐axis dipolar or quadrupolar internal field and significant finite Larmor radius effects at the boundary layer between magnetospheric and solar wind plasma environments. One important asymmetry appears in the growth and evolution of Kelvin‐Helmholtz (K‐H) waves at the dawn and dusk flanks of the magnetopause. Linear analysis and global hybrid simulations support a dusk‐dawn asymmetry in the growth rate caused by finite Larmor radius effects, and indeed, K‐H waves have been almost exclusively observed at the dusk magnetopause during northward interplanetary magnetic field. Observations of these K‐H waves at sodium gyroscales invite investigation into the impact of the hot planetary sodium ion population, itself distributed preferentially on the dusk flank, on the growth of the K‐H instability and associated plasma transport. We present local two‐dimensional hybrid simulations of the dusk and dawn boundary layers, with varying magnetospheric sodium ion number density, and examine the associated changes in the growth rates of the K‐H instability, K‐H wave spectra, and cross‐boundary particle transport. We show that gyroresonance between growing K‐H vortices and sodium ion gyration introduces a strong spectral peak at sodium gyroscales at the dusk magnetopause, that an increase in sodium ion number density increases dawn‐dusk asymmetry of K‐H growth rates, and that cross‐boundary particle transport decreases with sodium number density at the dawn flank.

show abstract

Extended fluid models: Pressure tensor effects and equilibria

Cited by 33 publications

References 32 publications

Nonlinear evolution of the magnetized Kelvin-Helmholtz instability: From fluid to kinetic modeling

Nonlinear evolution of the magnetized Kelvin-Helmholtz instability: From fluid to kinetic modeling

Pressure anisotropy generation in a magnetized plasma configuration with a shear flow velocity

The impact of a hot sodium ion population on the growth of the Kelvin‐Helmholtz instability in Mercury's magnetotail

Contact Info

Product

Resources

About