Accelerating the simulation of kinetic shear Alfvén waves with a dynamical low-rank approximation (2306.17526v1)
Abstract: We propose a dynamical low-rank algorithm for a gyrokinetic model that is used to describe strongly magnetized plasmas. The low-rank approximation is based on a decomposition into variables parallel and perpendicular to the magnetic field, as suggested by the physics of the underlying problem. We show that the resulting scheme exactly recovers the dispersion relation even with rank 1. We then perform a simulation of kinetic shear Alfv\'en waves and show that using the proposed dynamical low-rank algorithm a drastic reduction (multiple orders of magnitude) in both computational time and memory consumption can be achieved. We also compare the performance of robust first and second-order projector splitting, BUG (also called unconventional), and augmented BUG integrators as well as a FFT-based spectral and Lax--Wendroff discretization.
- A parallel low-rank solver for the six-dimensional Vlasov–Maxwell equations. J. Comput. Phys., 469:111562, 2022. doi: 10.1016/j.jcp.2022.111562.
- The Leja method revisited: Backward error analysis for the matrix exponential. SIAM J. Sci. Comput., 38(3):A1639–A1661, 2016.
- F. Cassini and L. Einkemmer. Efficient 6D Vlasov simulation using the dynamical low-rank framework Ensign. Comput. Phys. Commun., 280:108489, 2022.
- G. Ceruti and C. Lubich. Time integration of symmetric and anti-symmetric low-rank matrices and Tucker tensors. BIT Numer. Math., 60:591–614, 2020.
- G. Ceruti and C. Lubich. An unconventional robust integrator for dynamical low-rank approximation. BIT Numer. Math., 62:23–44, 2022.
- A rank-adaptive robust integrator for dynamical low-rank approximation. BIT Numer. Math., 62:1149–1174, 2022.
- Rank-adaptive time integration of tree tensor networks. SIAM J. Numer. Anal., 61(1):194–222, 2023.
- J. Coughlin and J. Hu. Efficient dynamical low-rank approximation for the Vlasov-Ampère-Fokker-Planck system. J. Comput. Phys., 470:111590, 2022. doi: 10.1016/j.jcp.2022.111590.
- T. Dannert and F. Jenko. Vlasov simulation of kinetic shear Alfvén waves. Comput. Phys. Commun., 163(2):67–78, 2004. doi: 10.1016/j.cpc.2004.09.001.
- P.J. Deka and L. Einkemmer. Exponential Integrators for Resistive Magnetohydrodynamics: Matrix-free Leja Interpolation and Efficient Adaptive Time Stepping. Astrophys. J. Suppl. Ser., 259(2):57, 2022a. doi: 10.3847/1538-4365/ac5177.
- P.J. Deka and L. Einkemmer. Efficient adaptive step size control for exponential integrators. Comput. Math. Appl., 123:59–74, 2022b. doi: 10.1016/j.camwa.2022.07.011.
- Dynamical Low-Rank Integrator for the Linear Boltzmann Equation: Error Analysis in the Diffusion Limit. SIAM J. Numer. Anal., 59(4), 2021.
- S.P. Nørsett E. Hairer, G. Wanner. Solving Ordinary Differential Equations I. Springer, 1993. doi: 10.1007/978-3-540-78862-1.
- V. Ehrlacher and D. Lombardi. A dynamical adaptive tensor method for the Vlasov–Poisson system. J. Comput. Phys., 339:285–306, 2017.
- L. Einkemmer. An adaptive step size controller for iterative implicit methods. Appl. Numer. Math., 132:182–204, 2018. doi: 10.1016/j.apnum.2018.06.002.
- L. Einkemmer. A low-rank algorithm for weakly compressible flow. SIAM J. Sci. Comput., 41(5):A2795–A2814, 2019a.
- L. Einkemmer. A performance comparison of semi-Lagrangian discontinuous Galerkin and spline based Vlasov solvers in four dimensions. Journal of Computational Physics, 376:937–951, 2019b.
- L. Einkemmer and I. Joseph. A mass, momentum, and energy conservative dynamical low-rank scheme for the Vlasov equation. J. Comput. Phys., 443:110495, 2021.
- L. Einkemmer and C. Lubich. A low-rank projector-splitting integrator for the Vlasov–Poisson equation. SIAM J. Sci. Comput., 40:B1330–B1360, 2018.
- L. Einkemmer and A. Ostermann. An almost symmetric Strang splitting scheme for nonlinear evolution equations. Comput. Math. with Appl., 67(12):2144–2157, 2014a. doi: 10.1016/j.camwa.2014.02.027.
- L. Einkemmer and A. Ostermann. An almost symmetric Strang splitting scheme for the construction of high order composition methods. J. Comput. Appl. Math., 271:307–318, 2014b. doi: 10.1016/j.cam.2014.04.015.
- A low-rank projector-splitting integrator for the Vlasov–Maxwell equations with divergence correction. J. Comput. Phys., 403:109063, 2020.
- An asymptotic-preserving dynamical low-rank method for the multi-scale multi-dimensional linear transport equation. J. Comput. Phys., 439(110353), 2021a.
- An Efficient Dynamical Low-Rank Algorithm for the Boltzmann-BGK Equation Close to the Compressible Viscous Flow Regime. SIAM J. Sci. Comput., 43(5):B1057–B1080, 2021b. doi: 10.1137/21m1392772.
- A robust and conservative dynamical low-rank algorithm. J. Comput. Phys., 484:112060, 2023.
- A drift-kinetic Semi-Lagrangian 4D code for ion turbulence simulation. J. Comput. Phys., 217(2):395–423, 2006. doi: https://doi.org/10.1016/j.jcp.2006.01.023.