Changes between Version 6 and Version 7 of doc/tec/pres

Timestamp:

Sep 19, 2016 11:57:36 AM (8 years ago)

Author:

Giersch

Comment:

--

doc/tec/pres

@@ -38 +38 @@
 
 In case of cyclic lateral boundary conditions, the solution of the Poisson equation is achieved by using a direct fast Fourier transform (FFT). The Poisson equation is Fourier transformed in both horizontal directions, the resulting tri-diagonal matrix is solved along the "z" direction, and then transformed back ([#schumann1988 see, e.g., Schumann and Sweet, 1988]). PALM provides the inefficient but less restrictive Singleton-FFT ([#singleton1969 Singleton, 1969])
-and the well optimized Temperton-FFT ([#temperton1992 Temperton, 1992]). External FFT libraries can be used as well, with the FFTW ([#frigo1998 Frigo and Johnson, 1998]) being the most efficient one. Alternatively, the iterative multigrid scheme can be used ([#hackbusch1985 e.g., Hackbusch, 1985]). This scheme uses an iterative successive over-relaxation (SOR) method for the inner iterations on each grid level. The convergence of this scheme is steered by the number of so-called V- or W-cycles to be carried out for each call of the scheme and by the number of SOR iterations to be carried out on each grid level. As the multigrid scheme does not require periodicity along the horizontal directions, it allows for using non-cyclic lateral boundary conditions.
+and the well optimized Temperton-FFT ([#temperton1992 Temperton, 1992]). External FFT libraries can be used as well, with the FFTW ([#frigo1998 Frigo and Johnson, 1998]) being the most efficient one. Alternatively, the iterative multigrid scheme can be used ([#hackbusch1985 e.g., Hackbusch, 1985]). This scheme uses the Gauss–Seidel method for the inner iterations on each grid level. The convergence of this scheme is steered by the number of so-called V- or W-cycles to be carried out for each call of the scheme and by the number of Gauss–Seidel iterations to be carried out on each grid level. As the multigrid scheme does not require periodicity along the horizontal directions, it allows for using non-cyclic lateral boundary conditions.
 
 == References ==