ABSTRACT
Ixx +/yy = F(x,y) (9.122) where F(x, y) is the nonhomogeneous term. The second-order centered-space approximation of Eq. (9.122) is given by Eq. (9.120) with the term MFi,J included:
;;+I,J + rl;;,J+' +;;-I,J + rl;;.J-I - 2(1 + rl)/j,J = Ax2 Fi•J (9.123) where f3 is the grid aspect ratio, f3 = Ax/!1y. Subroutine pdeJ presented in Section 9.13.1 for solving the Laplace equation includes the nonhomogeneous term F(x, y). Consequently, that subroutine also solves the Poisson equation. The only difference is that the variable specifying the value of the nonhomogeneous term fty must be specified.
