The Von Neumann conditions for the upwind and Lax-Wendroff schemes of the Telegraph Equation

Abstract

In this paper, the Von Neumann conditions for the Upwind and Lax-Wendroff schemes of the Telegraph Equation are derived, but then prove to be contradicted with the proportional relation between time and space steps, determined by voltage and current waves' propagation velocity. The contradiction implies that the stable Upwind and Lax-Wendroff schemes of the Telegraph Equation are not physically applicable.