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The analytic form of a new class of factorized Runge-Kutta-Chebyshev (FRKC) stability polynomials of arbitrary order N is presented. Roots of FRKC stability polynomials of degree L = MN are used to construct explicit schemes comprising L forward Euler stages with internal stability ensured through a sequencing algorithm which limits the internal amplification factors to ~ L2. The associated stability domain scales as M2 along the real axis. Marginally stable real-valued points on the interior of the stability domain are removed via a prescribed damping procedure. By construction, FRKC schemes meet all linear order conditions; for nonlinear problems at orders above 2, complex splitting or Butcher group composition methods are required. Linear order conditions of the FRKC stability polynomials are verified at orders 2, 4, and 6 in numerical experiments. Comparative studies with existing methods show the second-order unsplit FRKC2 scheme and higher order (4 and 6) split FRKC schemes are efficient for large moderately stiff problems.
http://doi.org 10. 1016/ j. jcp. 2015. 07. 050
O'Sullivan,S.(2015) A class of high-order Runge-Kutta-Chebyshev stability polynomials, Journal of Computational Physics doi: 10. 1016/ j. jcp. 2015. 07. 050