BROADBAND TRANSMISSION LOSS PERFORMANCE OF A HEMISPHERICAL END-CHAMBER MUFFLER WITH SINGLE ENDINLET AND SINGLE/DOUBLE END-OUTLET (Record no. 2615)
[ view plain ]
| 000 -LEADER | |
|---|---|
| fixed length control field | 03108nam a22001577a 4500 |
| 003 - CONTROL NUMBER IDENTIFIER | |
| control field | OSt |
| 005 - DATE AND TIME OF LATEST TRANSACTION | |
| control field | 20160722143643.0 |
| 008 - FIXED-LENGTH DATA ELEMENTS--GENERAL INFORMATION | |
| fixed length control field | 160722b xxu||||| |||| 00| 0 eng d |
| 040 ## - CATALOGING SOURCE | |
| Transcribing agency | National Acoustic Laboratories |
| 100 ## - MAIN ENTRY--PERSONAL NAME | |
| Personal name | Mimani, Akhilesh |
| 245 ## - TITLE STATEMENT | |
| Title | BROADBAND TRANSMISSION LOSS PERFORMANCE OF A HEMISPHERICAL END-CHAMBER MUFFLER WITH SINGLE ENDINLET AND SINGLE/DOUBLE END-OUTLET |
| 520 3# - SUMMARY, ETC. | |
| Summary, etc | The axially short circular/elliptical cylindrical chamber is often used as a flow-reversing or straightflow<br/>end-chamber in a multi-pass perforated duct muffler, a typical component of a modern-day<br/>automotive exhaust system. However, due to its small expansion volume, such short end chambers<br/>yield low acoustic attenuation (expressed in terms of Transmission Loss (TL)) in the low-frequency<br/>range, induce a large back pressure and increasing the chamber length results in the occurrence of a<br/>trough (due to the first axial mode) at a lower frequency that deteriorates the TL performance. In view<br/>of these limitations, the use of a different geometry, namely, a rigid-wall hemispherical cavity as a<br/>flow-reversal end-chamber muffler is investigated for potentially enhancing the TL performance over a<br/>wider frequency range, especially at low frequencies. To this end, this paper analyses the TL<br/>performance of a hemispherical end-chamber muffler having a single end-inlet and single/double endoutlet<br/>by means of a 3-D semi-analytical formulation based on the modal expansion of the acoustic<br/>field and the Green’s function approach. The 3-D acoustic field inside the rigid-wall hemispherical<br/>end-chamber is expressed in terms of the orthogonal modal functions. The hemispherical end-chamber<br/>muffler system is characterised using the uniform piston-driven model in terms of the impedance [Z]<br/>matrix parameters obtained by computing the average of the 3-D Green’s function over the surface<br/>area of the ports which are modelled as rigid pistons. The TL graphs computed by using the 3-D semianalytical<br/>formulation are found to be in an excellent agreement with that obtained from the 3-D FEA,<br/>thereby validating the technique used here. Furthermore, the 3-D modal expansion method enables one<br/>to take into account, the relative polar angular location between the ports and also determine their<br/>optimal radial offset distance (corresponding to appropriate pressure nodes on the end face) to obtain a<br/>broadband TL performance. A comparison of the TL performance of the optimised hemispherical endchamber<br/>muffler with that of an equivalent circular end-chamber having an equal volume demonstrates<br/>a significantly higher frequency range over which a broadband attenuation is obtained by using the<br/>hemispherical cavity. Similarly, a comparison with the TL graph of an equivalent axially short circular<br/>end-chamber indicates that the former exhibits higher attenuation in the low-frequency range. |
| 773 0# - HOST ITEM ENTRY | |
| Title | Acoustics 2015 Hunter Valley 15-18 November 2015 |
| 856 ## - ELECTRONIC LOCATION AND ACCESS | |
| Uniform Resource Identifier | <a href="http://dspace.nal.gov.au/xmlui/bitstream/handle/123456789/427/p97.pdf?sequence=1&isAllowed=y">http://dspace.nal.gov.au/xmlui/bitstream/handle/123456789/427/p97.pdf?sequence=1&isAllowed=y</a> |
| 942 ## - ADDED ENTRY ELEMENTS (KOHA) | |
| Source of classification or shelving scheme | Universal Decimal Classification |
| Koha item type | Journal article |
No items available.