TY - JOUR
T1 - Finite element methods for the helmholtz equation in an exterior domain
T2 - Model problems
AU - Harari, Isaac
AU - Hughes, Thomas J.R.
N1 - Funding Information:
was supported by the U.S. Office of Naval Research under Contracts N00014-89-K-0027 and
PY - 1991/5
Y1 - 1991/5
N2 - Finite element methods are presented for the reduced wave equation in unbounded domains. Model problems of radiation with inhomogeneous Neumann boundary conditions, including the effects of a moving acoustic medium, are examined for the entire range of propagation and decay. Exterior boundary conditions for the computational problem over a finite domain are derived from an exact relation between the solution and its derivatives on that boundary. Galerkin, Galerkin/least-squares and Galerkin/gradient least-squares finite element methods are evaluated by comparing errors pointwise and in integral norms. The Galerkin/least-squares method is shown to exhibit superior behavior for this class of problems.
AB - Finite element methods are presented for the reduced wave equation in unbounded domains. Model problems of radiation with inhomogeneous Neumann boundary conditions, including the effects of a moving acoustic medium, are examined for the entire range of propagation and decay. Exterior boundary conditions for the computational problem over a finite domain are derived from an exact relation between the solution and its derivatives on that boundary. Galerkin, Galerkin/least-squares and Galerkin/gradient least-squares finite element methods are evaluated by comparing errors pointwise and in integral norms. The Galerkin/least-squares method is shown to exhibit superior behavior for this class of problems.
UR - http://www.scopus.com/inward/record.url?scp=0026153971&partnerID=8YFLogxK
U2 - 10.1016/0045-7825(91)90146-W
DO - 10.1016/0045-7825(91)90146-W
M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???
AN - SCOPUS:0026153971
SN - 0045-7825
VL - 87
SP - 59
EP - 96
JO - Computer Methods in Applied Mechanics and Engineering
JF - Computer Methods in Applied Mechanics and Engineering
IS - 1
ER -