×

Implementation of the full viscoresistive magnetohydrodynamic equations in a nonlinear finite element code. (English) Zbl 1349.76216

Summary: Numerical simulations form an indispensable tool to understand the behavior of a hot plasma that is created inside a tokamak for providing nuclear fusion energy. Various aspects of tokamak plasmas have been successfully studied through the reduced magnetohydrodynamic (MHD) model. The need for more complete modeling through the full MHD equations is addressed here. Our computational method is presented along with measures against possible problems regarding pollution, stability, and regularity. The problem of ensuring continuity of solutions in the center of a polar grid is addressed in the context of a finite element discretization of the full MHD equations. A rigorous and generally applicable solution is proposed here. Useful analytical test cases are devised to verify the correct implementation of the momentum and induction equation, the hyperdiffusive terms, and the accuracy with which highly anisotropic diffusion can be simulated. A striking observation is that highly anisotropic diffusion can be treated with the same order of accuracy as isotropic diffusion, even on non-aligned grids, as long as these grids are generated with sufficient care. This property is shown to be associated with our use of a magnetic vector potential to describe the magnetic field. Several well-known instabilities are simulated to demonstrate the capabilities of the new method. The linear growth rate of an internal kink mode and a tearing mode are benchmarked against the results of a linear MHD code. The evolution of a tearing mode and the resulting magnetic islands are simulated well into the nonlinear regime. The results are compared with predictions from the reduced MHD model. Finally, a simulation of a ballooning mode illustrates the possibility to use our method as an ideal MHD method without the need to add any physical dissipation.

MSC:

76M10 Finite element methods applied to problems in fluid mechanics
65M60 Finite element, Rayleigh-Ritz and Galerkin methods for initial value and initial-boundary value problems involving PDEs
76W05 Magnetohydrodynamics and electrohydrodynamics

References:

[1] Sovinec, C. R.; Glasser, A. H.; Gianakon, T. A.; Barnes, D. C.; Nebel, R. A., Nonlinear magnetohydrodynamics simulations using high-order finite elements, J. Comput. Phys., 195, 355-386 (2004) · Zbl 1087.76070
[2] Sovinec, C. R.; King, J. R., Analysis of a mixed semi-implicit/implicit algorithm for low-frequency two-fluid plasma modeling, J. Comput. Phys., 229, 5803-5819 (2010) · Zbl 1346.82036
[3] Dudson, B. D.; Umansky, M. V.; Xu, X. Q.; Snyder, P. B.; Wilson, H. R., BOUT++: a framework for parallel plasma fluid simulations, Comput. Phys. Commun., 180, 1467-1480 (2009) · Zbl 07872388
[4] Dudson, B. D.; Xu, X. Q.; Umansky, M. V.; Wilson, H. R.; Snyder, P. B., Simulation of edge localized modes using BOUT++, Plasma Phys. Control. Fusion, 53, Article 054005 pp. (2011)
[5] Ferraro, N. M.; Jardin, S. C., Calculations of two-fluid magnetohydrodynamic axisymmetric steady-states, J. Comput. Phys., 228, 7742-7770 (2009) · Zbl 1391.76324
[6] Breslau, J.; Ferraro, N.; Jardin, S., Some properties of the M3D-\(C^1\) form of the three-dimensional magnetohydrodynamics equations, Phys. Plasmas, 16, Article 092503 pp. (2009)
[7] Lütjens, H.; Luciani, J.-F., The XTOR code for nonlinear 3D simulations of MHD instabilities in tokamak plasmas, J. Comput. Phys., 227, 6944-6966 (2008) · Zbl 1338.76143
[8] Lütjens, H.; Luciani, J.-F., XTOR-2F: a fully implicit Newton-Krylov solver applied to nonlinear 3D extended MHD in tokamaks, J. Comput. Phys., 229, 8130-8143 (2010) · Zbl 1220.76055
[9] Charlton, L. A.; Holmes, J. A.; Hicks, H. R.; Lynch, V. E.; Carreras, B. A., Numerical calculations using the full MHD equations in toroidal geometry, J. Comput. Phys., 63, 107-129 (1986) · Zbl 0587.76075
[10] Todo, Y.; Shinohara, K.; Takechi, M.; Ishikawa, M., Nonlocal energetic particle mode in a JT-60U plasma, Phys. Plasmas, 12, Article 012503 pp. (2005)
[11] Huysmans, G. T.A., External kink (peeling) modes in x-point geometry, Plasma Phys. Control. Fusion, 47, 2107-2121 (2005)
[12] Huysmans, G. T.A., ELMs: MHD instabilities at the transport barrier, Plasma Phys. Control. Fusion, 47, B165-B178 (2005)
[13] Huysmans, G. T.A., MHD stability in X-point geometry: simulation of ELMs, Nucl. Fusion, 47, 659-666 (2007)
[14] Huysmans, G. T.A.; Pamela, S.; van der Plas, E.; Ramet, P., Non-linear MHD simulations of edge localized modes (ELMs), Plasma Phys. Control. Fusion, 51, Article 124012 pp. (2009)
[15] Pamela, S. J.P.; Huysmans, G. T.A.; Beurskens, M. N.A.; Devaux, S.; Eich, T., Nonlinear MHD simulations of edge-localized-modes in JET, Plasma Phys. Control. Fusion, 53, 5, Article 054014 pp. (2011)
[16] Hölzl, M.; Günter, S.; Wenninger, R. P.; Müller, W. C.; Huysmans, G. T.A., Reduced-magnetohydrodynamic simulations of toroidally and poloidally localized edge localized modes, Phys. Plasmas, 19, 8, Article 082505 pp. (2012)
[17] Pamela, S.; Huysmans, G.; Benkadda, S., Influence of poloidal equilibrium rotation in MHD simulations of edge-localized modes, Plasma Phys. Control. Fusion, 52, 7, Article 075006 pp. (2010)
[18] Nardon, E.; Bécoulet, M.; Huysmans, G.; Czarny, O., Magnetohydrodynamics modelling of H-mode plasma response to external resonant magnetic perturbations, Phys. Plasmas, 14, Article 092501 pp. (2007)
[19] Orain, F.; Bécoulet, M.; Huysmans, G.; Dif-Pradalier, G.; Grandgirard, V., Interaction of resonant magnetic perturbations with flows in toroidal geometry, (39th EPS Conference on Plasma Physics, vol. 4 (2012)), 65
[20] Reux, C.; Huysmans, G.; Bucalossi, J.; Bécoulet, M., Non-linear simulations of disruption mitigation using massive gas injection on tore supra, (38th EPS Conf. Plasma Phys., vol. 3 (2011)), 117
[21] Czarny, O.; Huysmans, G., Bézier surfaces and finite elements for MHD simulations, J. Comput. Phys., 227, 7423-7445 (2008) · Zbl 1141.76035
[22] Huysmans, G. T.A., Implementation of an iterative solver in the non-linear MHD code JOREK (2006), ANR, Technical report
[23] Edlund, E. M.; Porkolab, M.; Kramer, G. J.; Lin, L.; Lin, Y.; Tsujii, N.; Wukitch, S. J., Experimental study of reversed shear Alfvén eigenmodes during the current ramp in the Alcator C-Mod tokamak, Plasma Phys. Control. Fusion, 52, Article 115003 pp. (2010)
[24] Xu, X. Q.; Dudson, B. D.; Snyder, P. B.; Umansky, M. V.; Wilson, H. R.; Casper, T., Nonlinear ELM simulations based on a nonideal peeling-ballooning model using the BOUT++ code, Nucl. Fusion, 51, 10, Article 103040 pp. (2011)
[25] Helzel, C.; Rossmanith, J. A.; Taetz, B., An unstaggered constrained transport method for the 3D ideal magnetohydrodynamic equations, J. Comput. Phys., 230, 3803-3829 (2011) · Zbl 1369.76061
[26] Huysmans, G. T.A.; Abgrall, R.; Bécoulet, M.; Huart, R.; Nkonga, B., Non-linear MHD simulations of ELMs, (35rd EPS Conference on Plasma Physics, vol. 32D (2008)), 2.065
[27] Hölzl, M.; Merkel, P.; Huysmans, G. T.A.; Nardon, E.; Strumberger, E.; McAdams, R.; Chapman, I.; Günter, S.; Lackner, K., Coupling JOREK and STARWALL codes for non-linear resistive-wall simulations, J. Phys., 401, Article 012010 pp. (2012)
[28] Haverkort, J. W., Magnetohydrodynamic waves and instabilities in rotating tokamak plasmas (2013), Eindhoven University of Technology, PhD thesis
[29] Goedbloed, J. P.; Poedts, S., Principles of Magnetohydrodynamics (2004), Cambridge University Press
[30] Haverkort, J. W.; de Blank, H. J.; Koren, B., The Brunt-Väisälä frequency of rotating tokamak plasmas, J. Comput. Phys., 231, 981-1001 (2012) · Zbl 1380.76166
[31] Beliën, A. J.C.; Botchev, M. A.; Goedbloed, J. P.; van der Holst, B.; Keppens, R., FINESSE: axisymmetric MHD equilibria with flow, J. Comput. Phys., 11, 182, 91-117 (2002) · Zbl 1021.76026
[32] Hairer, E.; Wanner, G., Solving Ordinary Differential Equations II: Stiff and Differential-Algebraic Problems (1996), Springer · Zbl 0859.65067
[33] Hénon, P.; Ramet, P.; Roman, J., On finding approximate supernodes for an efficient block-ILU(k) factorization, Parallel Comput., 34, 6, 345-362 (2008)
[34] Beam, R. M.; Warming, R. F., Alternating direction implicit methods for parabolic equations with a mixed derivative, SIAM J. Sci. Stat. Comput., 1, 1, 131-159 (1980) · Zbl 0462.65060
[35] Dahlquist, G. G., A special stability problem for linear multistep methods, BIT Numer. Math., 3, 27-43 (1963) · Zbl 0123.11703
[36] Chupin, A.; Stepanov, R., Full perturbation solution for the flow in a rotating torus, Phys. Rev. E, 77, Article 057301 pp. (2008)
[37] Goedbloed, J. P.; Beliën, A. J.C.; van der Holst, B.; Keppens, R., Unstable continuous spectra of transonic axisymmetric plasmas, Phys. Plasmas, 11, 28-54 (2004)
[38] Blokland, J. W.S.; van der Holst, B.; Keppens, R.; Goedbloed, J. P., PHOENIX: MHD spectral code for rotating laboratory and gravitating astrophysical plasmas, J. Comput. Phys., 226, 509-533 (2007) · Zbl 1310.76189
[39] Burke, B. J.; Kruger, S. E.; Hegna, C. C.; Zhu, P.; Snyder, P. B.; Sovinec, C. R.; Howell, E. C., Edge localized linear ideal magnetohydrodynamic instability studies in an extended-magnetohydrodynamic code, Phys. Plasmas, 17, Article 032103 pp. (2010)
[40] Ferraro, N. M.; Jardin, S. C.; Snyder, P. B., Ideal and resistive edge stability calculations with \(\text{M3D-C}^1\), Phys. Plasmas, 17, Article 102508 pp. (2010)
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.