Contribution
Efficient sensitivity analysis of classical Helmholtz resonators based on polynomial chaos expansion
* Presenting author
Abstract:
The reduction of unwanted airborne sound plays an important role in various applications, e.g. in room acoustics. The advantages of classic Helmholtz resonators over porous absorbers lie primarily in their narrow-band absorption behaviour in low frequency ranges. As the resonant frequency and the absorption behaviour are significantly influenced by the geometric design parameters, this contribution concentrates on determining the sensitivities of the two acoustic quantities. For this purpose, an analytical model based on the transfer matrix method is first presented and then a global sensitivity analysis is carried out. Instead of calculating the Sobol indices with a Monte Carlo-based sampling approach, an efficient surrogate modelling method, the polynomial chaos expansion, is used. The quantification of the input parameters shows that all these parameters exhibit additive behaviour, i.e. the parameters have no interactions. While the absorption depends almost exclusively on the neck diameter, the other geometric parameters show a sensitive behaviour in relation to the resonance frequency. The temperature in the parameter space under consideration plays a subordinate role for both acoustic parameters.