[petsc-users] Can I use TS routines for operator split formulation

[Shriram Srinivasan]

  /Understood. But if you can define/describe the exact operator split method (i.e. what defines A and B) then we see how it could possibly be handled within TS.

    Our goal is, when possible, to make TS flexible enough to support some operator split methods, we can only do this by specific examples.

    Thanks

     Barry/


Au = (k grad(u)_x,  is a discretization of the flux in the x direction, 
while B is for flux in the y direction. These matrices are assembled by 
solving local elliptic problems in each cell following a  multiscale 
finite volume method.
  To begin, the operator split is done as follows:

u_t + Au = f ( considering only x dir fluxes) as (u* - u_n)/tau   + A u* 
= f and solve for u*

then u_t + B u = f (considering only y dir fluxes) as (u - u*)/tau + B u 
= f and solve for u at current level.

Since TS module cant be used, I shall have to do the time marching by 
writing my code. Perhaps I should be reusing the KSP solvers, since the 
sparsity pattern etc  will be unchanged at each time step.

Thanks,
Shriram

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