ACCURACY IN MODELING THE ACOUSTIC-WAVE EQUATION WITH CHEBYSHEV SPECTRAL FINITE-ELEMENTS

A quantitative study of dispersion in Chebyshev spectral finite elemen t solutions to the one- and two-dimensional scalar wave equations is p resented. The spectral elements employ central time differencing and t hree mass matrix treatments: consistent, row-summed and diagonal-scale d. The one-dimensional axisymmetric wave equation is also formulated a nd solved with Chebyshev spectral elements. The computationally effici ent, row-summed mass matrix formulation is shown to exhibit minimal di spersion. One- and two-dimensional examples highlight the effects of d ispersion.