Abstract
The main component for the reduction of the exhaust noise from internal combustion engine (IC-engine) is the properly designed silencer. In addition, the acoustic performance of the after treatment devices (ATD) has gained interest as noise reduction components. Typically an ATD for diesel engines is assembled from components such as selective catalytic reducers (SCR), diesel oxidation catalysts (DOC) and diesel particulate filters (DPF). One new alternative to the conventional DPF is the particle oxidation catalyst (POC(R)). The POC(R) substrate studied in this paper is of type POC-X, which consists of fine, corrugated metallic wire mesh screens piled askew and rolled into a cylindrical shape. According to earlier studies the acoustic behaviour of the filter with negligible flow can be estimated with reasonable accuracy starting from the Kirchhoff solution. It was also concluded earlier that treating the filter as an acoustic resistance gives good results in the plane wave frequency range with moderate Mach-number flow. In this paper, the experiments on the acoustic performance of the POC-X in the non-plane wave frequency range with low Mach-number flow (M=0.01) are introduced. Starting from the earlier findings, procedure to obtain an estimate for the acoustic performance of the filter in the entire audio frequency range is proposed. Using the computationally effective semi-empirical model presented in this paper is especially reasonable when optimizing the complete exhaust system of an IC-engine for the maximum noise reduction.
Original language | English |
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Title of host publication | 44th International Congress and Exposition on Noise Control Engineering |
Subtitle of host publication | INTER-NOISE 2015 |
Publisher | Institute of Noise Control Engineering |
Publication status | Published - 2015 |
MoE publication type | Not Eligible |
Event | 44th International Congress and Exposition on Noise Control Engineering, INTER-NOISE 2015 - San Francisco, United States Duration: 9 Aug 2015 → 12 Aug 2015 Conference number: 44 |
Conference
Conference | 44th International Congress and Exposition on Noise Control Engineering, INTER-NOISE 2015 |
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Abbreviated title | INTER-NOISE 2015 |
Country/Territory | United States |
City | San Francisco |
Period | 9/08/15 → 12/08/15 |
Keywords
- particle oxidation catalyst
- acoustics
- noise reduction
- transmission loss
- non-palne waves