Change search
ReferencesLink to record
Permanent link

Direct link
Simulation of sound propagation around a truck using numerical methods
2009 (English)Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
Abstract [en]

The main purpose of this thesis is to compare measured and calculated transfer functions. By doing so the accuracy of prediction in the numerical method and model is evaluated. Software utilizing the Boundary Element Method was used in order to calculate the sound propagation around a truck. Initially a control measurement and its corresponding calculation were performed in order to validate the intended methodology. The results from these confirmed that the software was able to produce results similar to the ones attained from the measurements. A series of measurements were made on a SCANIA truck in an anechoic room. The source was a dodecahedron that was moved around four stationary microphones positions. Matching calculations were launched with a frequency step of 25, 5 and 1 Hz. When comparing the results from the calculations with the ones from the measurements many similarities could be found, especially when using a narrower frequency step. Still many of the finer characteristics were lost in the calculations, something that could be caused by a number of things, to mention a few: the numerical truck is defined as completely stiff which is not a satisfactorily approximation of reality, the free field created in the software is to a greater extend more anechoic than the physical room used. The conclusion is that the numerical model offers more of an indication than an answer of how the sound field behaves. Yet these results may be improved if the number of elements is increased and the frequency step diminished, this would however prolong the calculation time. Another possibility is to tune the model even further and not assigning all sections as completely stiff.

Place, publisher, year, edition, pages
Keyword [en]
Technology, Acoustics, BEM, sounds, simulations, Sysnoise
Keyword [sv]
URN: urn:nbn:se:ltu:diva-50343ISRN: LTU-EX--09/109--SELocal ID: 79c0eabd-b531-4317-bf64-4be024ce67b8OAI: diva2:1023700
Subject / course
Student thesis, at least 30 credits
Educational program
Arenaprogrammes (2002-2014)
Validerat; 20101217 (root)Available from: 2016-10-04 Created: 2016-10-04Bibliographically approved

Open Access in DiVA

fulltext(11992 kB)0 downloads
File information
File name FULLTEXT01.pdfFile size 11992 kBChecksum SHA-512
Type fulltextMimetype application/pdf

Search outside of DiVA

GoogleGoogle Scholar
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

ReferencesLink to record
Permanent link

Direct link