Non Uniform Rational B-Splines and Lagrange approximations for time-harmonic acoustic scattering: accuracy and absorbing boundary conditions. Issue 1 (2nd January 2021)

• Record Type: Journal Article
• Authors: Dsouza, S.M.; Khajah, T.; Antoine, X; Bordas, S.P.A.; Natarajan, S.
• Is Part Of: Mathematical and computer modelling of dynamical systems. Volume 27:Issue 1(2021)
• Page Start: 263
• Page End: 294
• Publication Date: 2021-01-02
• Subjects: Time-harmonic acoustic scattering -- absorbing boundary conditions -- far-field expansion -- finite element method -- isogeometric analysis -- non-uniform rational B-splines; Engineering -- Mathematical models -- Periodicals; Computer simulation -- Periodicals; 515.39
• DOI: 10.1080/13873954.2021.1902355
• Languages: English
• ISSNs: 1387-3954

Abstract

ABSTRACT: The paper aims to evaluate the performance of the Lagrange-based finite element method and the non-uniform rational B-splines isogeometric analysis of time-harmonic acoustic exterior scattering problems using high-order local absorbing boundary conditions, in particular based on the Karp's and Wilcox's far-field expansions. The analysis of accuracy and convergence of both methods is achieved by observing the effect of the order of the approximating polynomial, the number of degrees of freedom, the wave number, and the absorbing boundary conditions tuning parameters. It is concluded that, regardless of the polynomial order, IGA provides a higher accuracy per degree of freedom compared to the traditional Lagrange-based finite element method.