Constrained hyperbolic divergence cleaning in smoothed particle magnetohydrodynamics with variable cleaning speeds

JOURNAL OF COMPUTATIONAL PHYSICS

卷:322

Article

Tricco, Terrence S.^1,2  Price, Daniel J.³  Bate, Matthew R.² 

[1] Univ Toronto, Canadian Inst Theoret Astrophys, 60 St George St, Toronto, ON M5S 3H8, Canada

[2] Univ Exeter, Sch Phys, Stocker Rd, Exeter EX4 4QL, Devon, England

[3] Monash Univ, Sch Phys & Astron, Monash Ctr Astrophys, Clayton, Vic 3800, Australia

关键词: Numerical methods;    Magnetic fields;    MHD;    Smoothed particle magnetohydrodynamics (SPMHD);    Divergence cleaning;    Astrophysics;   

DOI  :  10.1016/j.jcp.2016.06.053

来源: Elsevier

【 摘 要 】

We present an updated constrained hyperbolic/parabolic divergence cleaning algorithm for smoothed particle magnetohydrodynamics (SPMHD) that remains conservative with wave cleaning speeds which vary in space and time. This is accomplished by evolving the quantity psi/c(h) instead of psi. Doing so allows each particle to carry an individual wave cleaning speed, c(h), that can evolve in time without needing an explicit prescription for how it should evolve, preventing circumstances which we demonstrate could lead to runaway energy growth related to variable wave cleaning speeds. This modification requires only a minor adjustment to the cleaning equations and is trivial to adopt in existing codes. Finally, we demonstrate that our constrained hyperbolic/parabolic divergence cleaning algorithm, run for a large number of iterations, can reduce the divergence of the magnetic field to an arbitrarily small value, achieving. del center dot B = 0 to machine precision. (C) 2016 Elsevier Inc. All rights reserved.

【 授权许可】

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