TY - BOOK

T1 - Acoustic Finite Element Calculations in the Time Domain

AU - Jensen, Morten Skaarup

PY - 1996

Y1 - 1996

N2 - The use of the finite element method (FEM) for making predictions
for acoustic fields in the time domain is investigated. First, an
introduction to FEM for acoustics is given. This includes a
description of important present day algorithms and a derivation
of FEM. The overall performance of these algorithms is then
examined with particular emphasis on accuracy and computational
costs. It is shown that the most important error is one that takes
the form of a falsely predicted dispersion. The dispersion error
can be reduced by using smaller elements and time steps, but this
is very costly. Attempts were therefore made to find more
economical means of reducing this error. Direct attempts at
reducing the error were not very successful, but it was possible
to find techniques to reduce the computational cost of a
calculation. In the course of the project, a good understanding of
the origin and consequences of the dispersion error has been
obtained. This led to a new method for determining the optimum
element and time step size. The method is valuable because the
present way of doing this is not theoretically well-founded.

AB - The use of the finite element method (FEM) for making predictions
for acoustic fields in the time domain is investigated. First, an
introduction to FEM for acoustics is given. This includes a
description of important present day algorithms and a derivation
of FEM. The overall performance of these algorithms is then
examined with particular emphasis on accuracy and computational
costs. It is shown that the most important error is one that takes
the form of a falsely predicted dispersion. The dispersion error
can be reduced by using smaller elements and time steps, but this
is very costly. Attempts were therefore made to find more
economical means of reducing this error. Direct attempts at
reducing the error were not very successful, but it was possible
to find techniques to reduce the computational cost of a
calculation. In the course of the project, a good understanding of
the origin and consequences of the dispersion error has been
obtained. This led to a new method for determining the optimum
element and time step size. The method is valuable because the
present way of doing this is not theoretically well-founded.

M3 - Book

BT - Acoustic Finite Element Calculations in the Time Domain

PB - Department of Acoustic Technology, Technical University of Denmark

CY - Lyngby, Denmark

ER -