Hybrid Asymptotic-Numerical Methods in Scattering
Abstract
We have developed and studied hybrid asymptotic-numerical methods to compute the acoustic field scattered by a large object. The asymptotic approximation is based on a short wavelength expansion of the scattered field in the form of uniformly valid geometrical theory of diffraction. These were combined with two numerical methods: finite elements and boundary spectral strip methods. The coupling to finite elements was achieved with the introduction of a new variational principle to couple two incompatible approximations. The boundary spectral strip method is a spectral approximation applied to a boundary integral formulation of the boundary value problem. With this method, we have successfully evaluated diffraction coefficients, surface wave excitation coefficients, and solved large scattering problems with several diffraction points. We have also studied the error introduced by joining the numerical and asymptotic approximations, and determined its properties and scalings.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 05, 1999
- Accession Number
- ADA363046
Entities
People
- Paul E. Barbone
Organizations
- Boston University