A study of discretization error in the finite element approximation of wave solutions

A dispersion analysis is used to study the errors caused by the spatial discretization of the finite-element method for the two-dimensional scalar Helmholtz equation. It is shown that the error can be determined analytically for a uniform mesh of infinite extent. Numerical results are presented to show the effects of several parameters on the error. These parameters are the nodal density, the electrical size of the mesh, the direction of propagation of the incident wave, the type of element, and the type of boundary condition. >