Modeling scattering with edge diffraction Seminar
- Time:
- 16:00
- Date:
- 12 March 2013
- Venue:
- Building 13 room 3017
Event details
ISVR Engineering Research Seminar
External and internal scattering problems are often studied with geometrical acoustics (GA) approaches because accurate solution methods such as the finite element, finite differences, and boundary element methods might be prohibitively expensive to compute. A major limitation of common GA-based methods is their inability to model diffraction. Various formulations are available for the first-order diffraction by a single wedge, but higher orders are needed for more complex geometries. This presentation will introduce an edge source integral equation which facilitates the computation of high orders of diffraction at a constant cost per diffraction order. The integral equation has some similarities with the Kirchhoff-Helmholtz integral equation, but the unknown is the field along the edges of a scattering object. For rigid and convex scattering objects, very high accuracy results for the entire frequency range as shown by numerical examples for the scattering from discs and polyhedral approximations of spheres. Possibilities and limitations for more general problems, such as auditoria, will be discussed.
Speaker information
Peter Svensson , Norwegian University of Science and Technology. Peter gained his MSc in Engineering Physics in 1987, from the Chalmers University of Technology, Gothenburg, Sweden, and his PhD in 1994, from Chalmers Room Acoustics Group, Department of Applied Acoustics, Chalmers University of Technology, Gothenburg, Sweden. His PhD thesis was titled "On reverberation enhancement in auditoria". The project was partly financed by the Building Research Council. Peter was a guest researcher in 1995 at the University of Waterloo, Canada. He cooperated with John Vanderkooy in the Audio Research Group on edge diffraction models. The stay was financed by the Swedish Institute and the Adlerbert Research Foundation. In 1996, and 1997/98, Peter was a guest researcher in the Environmental Acoustics Laboratory, Kobe University, Japan. He worked with Masayuki Morimoto and Kimihiro Sakagami on the time domain formulation of the equivalent source method. Both stays in Japan were supported by the Japan Society for the Promotion of Science. Peter is currently a professor in electroacoustics at the Department of Telecommunications, Norwegian University of Science and Technology, Trondheim, Norway, and has held this post since 1999. He is a member of the Acoustical Society of America and the Audio Engineering Society.