Publications
The elusive cost function for tuning adaptive Helmholtz resonators
Sarabjeet Singh and Colin H. Hansen and Carl Q. Howard (2006)
Proceedings of Acoustics 2006: Noise of Progress, Clearwater Resort, Christchurch, New Zealand, 20-22 November, p75-82Abstract:
One of the problems associated with the use of Helmholtz resonators to control tonal noise propagation inside a pipe or duct is that any slight frequency changes in the tonal noise as a result of environmental changes or load changes on the device generating the noise will severely compromise the performance of the resonator. Thus, it is desirable to use an adaptive resonator whose volume or neck length can be adjusted to maintain optimal tuning as the excitation frequency or environmental conditions change. The ideal cost function would be a measure of the sound power propagating down the duct so the control system could minimise this quantity by driving motors that change the geometry of resonator. In practice, it is highly desirable to have available a self-contained adaptive resonator that does not need any external inputs or measures of quantities outside the resonator package. A cost function based on pressure measurements in the resonator, which corresponds to sound power in the duct has been found and verified experimentally and numerically. The effect of resonator damping on the cost function and a method to correct for the effect is also discussed.
This material is now only available to staff and students of the University of
Adelaide.
Should you wish to receive a copy, please contact the
AVC Group webmaster.
Note that if this article is under review, then it cannot be released and email requests will not be answered.
Manuscript - available for public access