Using micro-perforated plates to realize a silencer based on the Cremer impedance
2014 (English)In: Proceedings of Forum Acusticum, European Acoustics Association (EAA), 2014Conference paper (Refereed)Text
Current trends for IC-engines are driving the development of more efficient engines with higher specific power. This is true for both light and heavy duty vehicles and has led to an increased use of charging. The charging can be both in the form of a single or multi-stage turbo-charger driven by exhaust gases or via a directly driven compressor. In both cases a possible noise problem can be a strong Blade Passing Frequency (BPF) typically in the kHz range and above the plane wave range. In this paper a novel type of compact dissipative silencer developed especially to handle this type of problem is described. The silencer is based on a combination of a micro-perforated tube backed by a locally reacting cavity. The combined impedance of micro-perforate and cavity is chosen to match the theoretical optimum known as the Cremer impedance at the mid-frequency in the frequency range of interest. Due to the high damping achieved at the Cremer optimum (hundreds of dB/m) it is easy to create a compact silencer with a significant damping (say >40 dB) in a range larger than an octave. Several principles are presented to determine the parameters of micro-perforate and cavity. The numerical results indicate that, following the principles, a silencer with broad-band damping can be achieved.
Place, publisher, year, edition, pages
European Acoustics Association (EAA), 2014.
Damping, Engines, Internal combustion engines, Noise pollution, Perforated plates, Blade passing frequency, Directly-driven, Frequency ranges, Heavy duty vehicles, Mid-frequencies, Noise problems, Numerical results, Perforated tubes, Exhaust gases
IdentifiersURN: urn:nbn:se:kth:diva-181664ScopusID: 2-s2.0-84953310129ISBN: 9788361402282OAI: oai:DiVA.org:kth-181664DiVA: diva2:902602
7th Forum Acusticum, FA 2014, 7 September 2014 through 12 September 2014
QC 201602112016-02-112016-02-022016-02-11Bibliographically approved