| Summary: | 碩士 === 逢甲大學 === 機械工程研究所 === 84 === Real-world mufflers usually contain complex internal
geometry, such as extended inlet/outlet tubes, thin baffles, and
perforated tubes. Some of the problems can be solved by
commercial acoustic BEM (boundary element method) codes. In this
study, We present some initial results of using the indirect BEM
in SYSNOISE. The results are compared to available experimental
data as well as results from a direct mixed-body BEM code. The
transmission loss(TL) is evaluated by the three-point method,
instead of the conventional four-poletheory. The three-point
method requires only one single BEM run to get the TL value at
each frequency. Several test cases of increasing modeling
difficulty are evaluated, with the last one being very close to
a real-world motorcycle muffler.
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