WAVES AND VIBRATIONS IN INHOMOGENEOUS STRUCTURES ...

Systematic design of acoustic devices by topology optimization
Jakob Søndergaard Jensen and Ole Sigmund
Department of Mechanical Engineering, Solid Mechanics
Nils Koppels Allé, Building 404, Technical University of Denmark
DK-2800 Kgs. Lyngby, Denmark
jsj@mek.dtu.dk
Abstract
We present a method to design acoustic devices with topology optimization. The general algorithm
is exemplified by the design of a reflection chamber that minimizes the transmission of
acoustic waves in a specified frequency range.
INTRODUCTION
We treat the problem of designing acoustic devices with prescribed properties by using
topology optimization. The method is exemplified by the design of a reflection chamber
with minimized acoustic transmission in a designated frequency range.
A recent example of optimization of an acoustic devices, was given in [1], who
used a FEM-based shape optimization algorithm to design an acoustic horn with minimal
reflection for larger frequency ranges. In general, shape optimization employs a
parametrization of the original device geometry as a basis for obtaining an optimized
design. Thus, good results rely on the initial geometry as well as a suitable set of design
parameters. Contrary to this, topology optimization ([2]) is based on a point-(or
element-)wise parametrization of the material properties. This allows for, in principle,
unlimited design freedom, regardless of the initial geometry. The method is well
suited when good performance is hard to obtain with intuition-based design, which is
often the case for wave propagation phenomena. Preliminary studies of using topology
optimization to design acoustic devices were presented in [3] and [4], and the present
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