The main program sets up geometry of solution domain for 1-D advective diffusion with uniform density rho and conductivity Gamma. Patankar's power-law scheme is used for advection. For illustrative purposes only, you can change the parameter "upwind" to zero, in order to use the centered-difference scheme for comparison.

• The solution domain is set to be 1-D for this example, but the code should work for 2-D by setting nx>1.

• Fixed-temperature Boundary conditions at Up and Down (z) are applied on half-volumes, such that nodes are on boundaries, as described in Patankar.
• Zero fluxes on East and West boundaries are applied on faces of a single stack of Finite Volumes.

solve.m solves the resulting system of linear equations.