The Influence of Magnetic Fields on Star Formation

Byleveld, S. E.; Pongracic, H.

doi:10.1017/s1323358000020567

Cited by 4 publications

(4 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…126 was used as the basis of a number of early SPMHD formulations in which the force was simply computed using standard curl operators such as (54) or (79) (e.g. Meglicki, 1995;Byleveld and Pongracic, 1996;Cerqueira and de Gouveia Dal Pino, 2001;Hosking and Whitworth, 2004). However, the poor conservation properties of such formulations means that MHD shocks are not well captured.…”

Section: The Tensile Instability In Mhdmentioning

confidence: 99%

Smoothed particle hydrodynamics and magnetohydrodynamics

Price¹

2012

Journal of Computational Physics

611

673

View full text Add to dashboard Cite

This paper presents an overview and introduction to Smoothed Particle Hydrodynamics and Magnetohydrodynamics in theory and in practice. Firstly, we give a basic grounding in the fundamentals of SPH, showing how the equations of motion and energy can be self-consistently derived from the density estimate. We then show how to interpret these equations using the basic SPH interpolation formulae and highlight the subtle difference in approach between SPH and other particle methods. In doing so, we also critique several 'urban myths' regarding SPH, in particular the idea that one can simply increase the 'neighbour number' more slowly than the total number of particles in order to obtain convergence. We also discuss the origin of numerical instabilities such as the pairing and tensile instabilities. Finally, we give practical advice on how to resolve three of the main issues with SPMHD: removing the tensile instability, formulating dissipative terms for MHD shocks and enforcing the divergence constraint on the particles, and we give the current status of developments in this area. Accompanying the paper is the first public release of the ndspmhd SPH code, a 1, 2 and 3 dimensional code designed as a testbed for SPH/SPMHD algorithms that can be used to test many of the ideas and used to run all of the numerical examples contained in the paper.

show abstract

Section: The Tensile Instability In Mhdmentioning

confidence: 99%

Smoothed particle hydrodynamics and magnetohydrodynamics

Price¹

2012

Journal of Computational Physics

611

673

View full text Add to dashboard Cite

show abstract

“…Such an approach has also been used successfully in an SPMHD context by several authors (e.g. Benz 1984; Meglicki, Wickramasinghe & Dewar 1995; Byleveld & Pongracic 1996; Cerqueira & de Gouveia Dal Pino 2001), however, numerical simulations of shocks seem to require the exact conservation of momentum in order to provide the correct jump conditions at shock fronts (which means, at the very least, the discrete formulation should be based on continuum equations which conserve momentum exactly even with a non‐zero magnetic divergence).…”

Section: Introductionmentioning

confidence: 99%

Smoothed Particle Magnetohydrodynamics — III. Multidimensional tests and the ∇·B= 0 constraint

Price¹,

Monaghan²

2005

Monthly Notices of the Royal Astronomical Society

121

234

View full text Add to dashboard Cite

In two previous papers (Papers I and II), we have described an algorithm for solving the equations of Magnetohydrodynamics (MHD) using the Smoothed Particle Hydrodynamics (SPH) method. The algorithm uses dissipative terms in order to capture shocks and has been tested on a wide range of one-dimensional problems in both adiabatic and isothermal MHD. In this paper, we investigate multidimensional aspects of the algorithm, refining many of the aspects considered in Papers I and II and paying particular attention to the code's ability to maintain the ∇ · B = 0 constraint associated with the magnetic field. In particular, we implement a hyperbolic divergence cleaning method recently proposed by Dedner et al. in combination with the consistent formulation of the MHD equations in the presence of non-zero magnetic divergence derived in Papers I and II. Various projection methods for maintaining the divergence-free condition are also examined. Finally, the algorithm is tested against a wide range of multidimensional problems used to test recent grid-based MHD codes. A particular finding of these tests is that in Smoothed Particle Magnetohydrodynamics (SPMHD), the magnitude of the divergence error is dependent on the number of neighbours used to calculate a particle's properties and only weakly dependent on the total number of particles. Whilst many improvements could still be made to the algorithm, our results suggest that the method is ripe for application to problems of current theoretical interest, such as that of star formation.

show abstract

“…Around the same time Meglicki (1995) applied a non-conservative SPMHD formulation to magnetic fields in the Galaxy. The period after these works saw a few but limited applications of SPMHD to 'real' astrophysical problems, including notably an application to magnetic fields in galaxy clusters by Dolag, Bartelmann & Lesch (1999) † and at least one foray into star formation by Byleveld & Pongracic (1996). However it would be fair to say that there was no real consensus on a standard approach and that many problems remained.…”

Section: A Prehistory Of Mhd In Sphmentioning

confidence: 99%

Magnetic fields and Turbulence in Star Formation using Smoothed Particle Hydrodynamics

Price

2010

Proc. IAU

View full text Add to dashboard Cite

Abstract. Firstly, we give a historical overview of attempts to incorporate magnetic fields into the Smoothed Particle Hydrodynamics method by solving the equations of Magnetohydrodynamics (MHD), leading an honest assessment of the current state-of-the-art in terms of the limitations to performing realistic calculations of the star formation process. Secondly, we discuss the results of a recent comparison we have performed on simulations of driven, supersonic turbulence with SPH and Eulerian techniques.

show abstract

The Influence of Magnetic Fields on Star Formation

Cited by 4 publications

References 11 publications

Smoothed particle hydrodynamics and magnetohydrodynamics

Smoothed particle hydrodynamics and magnetohydrodynamics

Smoothed Particle Magnetohydrodynamics — III. Multidimensional tests and the ∇·B= 0 constraint

Magnetic fields and Turbulence in Star Formation using Smoothed Particle Hydrodynamics

Contact Info

Product

Resources

About