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

["Ben Tay" <zonexo@xxxxxxxxx>]

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