Posted by Koudella on July 14, 1998 at 17:10:23:

Hello,

I need to solve the following equation:

div( M(x,y,z) \nabla f(x,y,z) ) = g(x,y,z)

on a cubic boz with periodic bc's using a nice regular

grid.

M(x,y,z) is a 3x3 matrix, giving rise to mixed

derivatives in the pde. M is made up from a scalar

field, the result of a turbulence simulation and

thus M can vary strongly, though not discontinuously

I want to solve this equation using either finite

differences, finite vol or anything else.

Maybe you can give me a few hints concerning earlier

work, the discretisation and the inversion of the

big linear system I end up with.

by the way I am working with high resolution

(256^3).

thank you,

Christophe

ckoudell@ens-lyon.fr