The ICCG solver in the RIPPLE code

lasersim · March 22, 2012, 10:46

Is anyone familiar with the RIPPLE code from Los Alamos National Laboratory?
I have a question about the ICCG solver in it. In the comment lines, words like "periodic diagonals" and "periodic blocks" are mentioned. What do they mean? Thank you in advance!

Zach

CCKM · March 22, 2012, 17:48

I am NOT familiar with the RIPPLE code, but I have seen a matrix A = [a(i,j)] called a periodic Toeplitz matrix with period p, if a(i+p,j+p) = a(i,j) for all (i,j). In particular, a Toeplitz matrix could be considered periodic with period 1.

My best GUESS is that the diagonals in question are periodic, i.e. d(i) = d(i+p), and that the blocks are periodic Toeplitz matrices in the above sense.

A few people will also call a tridiagonal matrix with a non-zero entries in the (1,n) and the (n,1) corner 'periodic', presumably because this is the sparsity pattern you get when discretizing, say, the one dimensional heat equation with periodic boundary conditions.

/Carl Christian.

hilllike · March 22, 2012, 22:54

ICCG method is used to solve the linear equation with a symmetric coefficient matrix,you can find the detail on the book of Peric.

lasersim · March 23, 2012, 13:35

Thank you, Carl and Xingyue!

novan tofany · March 26, 2012, 04:08

Hello Zach, you seem familiar using RIPPLE,

i'm now working on developing my own code related to free surface flow,
until now i've only had references such as SOLA-VOF and NASA-VOF,and found that RIPPLE is the extended version of them..i'm interested to study it more.
i already have the RIPPLE report, but it seems that its source code is not free.. do you have it? if it's not bothering you, could you share the code..i'll be very very thank you if you do..

Regards
Novan

March 22, 2012, 10:46	The ICCG solver in the RIPPLE code	#1
lasersim New Member flyever Join Date: Mar 2012 Posts: 5 Rep Power: 14	Is anyone familiar with the RIPPLE code from Los Alamos National Laboratory? I have a question about the ICCG solver in it. In the comment lines, words like "periodic diagonals" and "periodic blocks" are mentioned. What do they mean? Thank you in advance! Zach

March 22, 2012, 22:54		#3
hilllike Member Ren/Xingyue Join Date: Jan 2010 Location: Nagoya , Japan Posts: 44 Rep Power: 16	ICCG method is used to solve the linear equation with a symmetric coefficient matrix,you can find the detail on the book of Peric. immortality likes this.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Transient simulation not converging	skabilan	OpenFOAM Running, Solving & CFD	14	December 16, 2019 23:12
thobois class engineTopoChangerMesh error	Peter_600	OpenFOAM	4	August 2, 2014 09:52
Getting error in running *.C code of solver	Tushar@cfd	OpenFOAM Running, Solving & CFD	1	January 5, 2010 03:09
Could anybody help me see this error and give help	liugx212	OpenFOAM Running, Solving & CFD	3	January 4, 2006 18:07
Automatic Mesh Motion solver	michele	OpenFOAM Running, Solving & CFD	10	September 26, 2005 08:21

March 22, 2012, 17:48		#2
CCKM New Member Carl Christian Kjelgaard Mikkelsen Join Date: Mar 2012 Posts: 7 Rep Power: 14	I am NOT familiar with the RIPPLE code, but I have seen a matrix A = [a(i,j)] called a periodic Toeplitz matrix with period p, if a(i+p,j+p) = a(i,j) for all (i,j). In particular, a Toeplitz matrix could be considered periodic with period 1. My best GUESS is that the diagonals in question are periodic, i.e. d(i) = d(i+p), and that the blocks are periodic Toeplitz matrices in the above sense. A few people will also call a tridiagonal matrix with a non-zero entries in the (1,n) and the (n,1) corner 'periodic', presumably because this is the sparsity pattern you get when discretizing, say, the one dimensional heat equation with periodic boundary conditions. /Carl Christian.

March 23, 2012, 13:35		#4
lasersim New Member flyever Join Date: Mar 2012 Posts: 5 Rep Power: 14	Thank you, Carl and Xingyue!

March 26, 2012, 04:08		#5
novan tofany New Member Novan Tofany Join Date: Feb 2011 Posts: 14 Rep Power: 15	Hello Zach, you seem familiar using RIPPLE, i'm now working on developing my own code related to free surface flow, until now i've only had references such as SOLA-VOF and NASA-VOF,and found that RIPPLE is the extended version of them..i'm interested to study it more. i already have the RIPPLE report, but it seems that its source code is not free.. do you have it? if it's not bothering you, could you share the code..i'll be very very thank you if you do.. Regards Novan