Kennedy, J., Adetifa, O., Carley, M., Holt, N. and Walker, I., 2011. Aeroacoustic sources of motorcycle helmet noise. The Journal of the Acoustical Society of America, 130 (3), pp. 1164-1172.
The prevalence of noise in the riding of motorcycles has been a source of concern to both riders and researchers in recent times. Detailed flow field information will allow insight into the flow mechanisms responsible for the production of sound within motorcycle helmets. Flow field surveys of this nature are not found in the available literature which has tended to focus on sound pressure levels at ear as these are of interest for noise exposure legislation. A detailed flow survey of a com- mercial motorcycle helmet has been carried out in combination with surface pressure measurements and at ear acoustics. Three potential noise source regions are investigated, namely, the helmet wake, the surface boundary layer and the cavity under the helmet at the chin bar. Extensive infor- mation is provided on the structure of the helmet wake including its frequency content. While the wake and boundary layer flows showed negligible contributions to at-ear sound the cavity region around the chin bar was identified as a key noise source. The contribution of the cavity region was investigated as a function of flow speed and helmet angle both of which are shown to be key factors governing the sound produced by this region.
|Item Type ||Articles|
|Creators||Kennedy, J., Adetifa, O., Carley, M., Holt, N. and Walker, I.|
|Departments||Faculty of Engineering & Design > Mechanical Engineering|
|Research Centres||Aerospace Engineering Research Centre|
|Publisher Statement||JASMAN13031164_1.pdf: Copyright (2011) Acoustical Society of America. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the Acoustical Society of America. The following article appeared in Kennedy, J., Adetifa, O., Carley, M., Holt, N. and Walker, I., 2011. Aeroacoustic sources of motorcycle helmet noise. The Journal of the Acoustical Society of America, 130 (3), pp. 1164-1172, and may be found at http://dx.doi.org/10.1121/1.3621097|
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