Minimization of numerical dispersion errors in 2D finite element models of short acoustic wave propagation

Abstract

Numerical dispersion errors are inherent for simulations based on wave propagation models with discrete meshes. The paper presents approach ap-plied to reduce errors of this type in finite element models. High order 2D syn-thesized finite elements with enhanced convergence properties are obtained by modal synthesis technique. Obtained elements have diagonal mass matrix which enables to employ explicit integration schemes for wave simulation. Waves of more than two times wider frequency can be simulated using model of synthe-sized elements compared to models assembled of conventional elements. Fur-thermore, such elements could be used as a template of higher-order element to construct finite element models for all simulation problems of this kind.Keywords: finite elements, wave propagation, numerical dispersion, modal synthesis.