Change search
ReferencesLink to record
Permanent link

Direct link
Linear Acoustic Modelling and Testing of Exhaust Mufflers
KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
2007 (English)Student thesis
Abstract [en]

Intake and Exhaust system noise makes a huge contribution to the interior and exterior noise of automobiles. There are a number of linear acoustic tools developed by institutions and industries to predict the acoustic properties of intake and exhaust systems. The present project discusses and validates, through measurements, the proper modelling of these systems using BOOST-SID and discusses the ideas to properly convert a geometrical model of an exhaust muffler to an acoustic model. The various elements and their properties are also discussed.

When it comes to Acoustic properties there are several parameters that describe the performance of a muffler, the Transmission Loss (TL) can be useful to check the validity of a mathematical model but when we want to predict the actual acoustic behavior of a component after it is installed in a system and subjected to operating conditions then we have to determine other properties like Attenuation, Insertion loss etc,.

Zero flow and Mean flow (M=0.12) measurements of these properties were carried out for mufflers ranging from simple expansion chambers to complex geometry using two approaches 1) Two Load technique 2) Two Source location technique. For both these cases, the measured transmission losses were compared to those obtained from BOOST-SID models.

The measured acoustic properties compared well with the simulated model for almost all the cases.

Place, publisher, year, edition, pages
2007. , 105 p.
Trita-AVE, ISSN 1651-7660
Keyword [en]
Acoustic Modelling, Exhaust System, Muffler, End Corrections, Transfer Matrix, Acoustical two port, Acoustical one port, Two Microphone Method (TMM), Transmission Loss, Attenuation, Reflection Co-efficient, AVL Boost
National Category
Fluid Mechanics and Acoustics
URN: urn:nbn:se:kth:diva-4340OAI: diva2:11878

Available from: 2008-12-23 Created: 2008-12-23 Last updated: 2010-04-28

Open Access in DiVA

fulltext(1510 kB)6933 downloads
File information
File name FULLTEXT01.pdfFile size 1510 kBChecksum SHA-1
Type fulltextMimetype application/pdf

By organisation
Aeronautical and Vehicle Engineering
Fluid Mechanics and Acoustics

Search outside of DiVA

GoogleGoogle Scholar
Total: 6933 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 390 hits
ReferencesLink to record
Permanent link

Direct link