Wave Propagation in Quadratic-Finite-Element Approximations to Hyperbolic Equations
Dale R. Durran
ABSTRACT
Eigenmodes for the quadratic-finite-element method are expressed as a
linear combination of two conventional semi-discrete Fourier
modes. Each of these Fourier modes moves at a different phase
speed, but both modes have the same group velocity. This
representation of the QFEM eigenmodes clarifies the significance
of the negative phase speeds that naturally arise as part of the
conventional analysis.
Preprint text and figures (postscript)