How is the sys of linear eqns solved using PETSc in this application?

[Matthew Knepley]

PETSc only solves algebraic equations, although the DA construct can
handle Cartesian meshes. Thus it will solve either of these systems if
you set it up.
Explicit methods would probably use TS, and implicit DMMG.

  Matt

On 7/30/07, Ben Tay <zonexo at gmail.com> wrote:
> Hi,
>
> I'm formulating a NS solver which computes the flow past an airfoil. The
> airfoil has a c-grid and it overlaps with the background cartesian grid. In
> other words, it is a chimera or overset grid application.
>
> The boundary cells of the c-grid are connected to the cartesian grid thru
> interpolation stencil. One way to solve the problem is to solved implicitly
> ie for each cell
> phi(c-grid)=a1*phi(cart,1)+a2*phi(cart,2)+a3*phi(cart,3)+a4*phi(cart,4)
> and vice versa for the phi(cart). This is entered into the sys of linear
> eqns comprising of c-grid and cartesian and solved all at once.
>
> Another way is to solve the cartesian grid eqns fully 1st, compute
> phi(c-grid) using the known phi(cart,*) and solve the c-grid fully ie
> explicit solving.
>
> Is it possible to do this in PETSc:
>
> 1. Do 1 iteration of cartesian grid eqns
> 2. compute phi(c-grid) using the newly iterated phi(cart,*) values
> 3. Do 1 iteration of c-grid eqns
> 4. compute phi(cart) using the newly iterated phi(c-grid,*) values
> 5. go back to 1.
>
> Or is this mtd the same as solving the whole sys implicitly (ie 1st case)?
>
> Thanks


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What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which
their experiments lead.
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