Abstract
Here we use a more convenient technique to generate a faster convergent Green's function needed for solving Laplace's equation in two cases: the first domain is bounded by two parallel planes; and the second is an infinite open rectangular prism. Green's function usually is expressed as a series of images which is slowly convergent, and that is why we transform it into an integral representation which is rapidly convergent and stable. Many examples are herein given and discussed for the numerical applications of the above two cases; and then we make a comparison between our calculations and some others.