An Enhanced Analogy Serial-Parallel Mass-Spring System Analytical Model for Sound Reduction Frequency of Resonators With Multiple Necks

Abstract Side-branch resonators are widely used for noise control. Compared to a resonator with a single neck, a resonator with multiple necks can achieve higher frequency sound reduction and better sound reduction performance using the same branch cavity. However, accurately predicting the sound reduction frequency for resonators with multiple necks using a general model remains a challenging problem. In a previous study, a continuous analogy serial-parallel mass-spring system (ASPMSS) analytical model was developed based on the principles of mass and energy conservation to analyze and predict the sound reduction frequency of resonators with randomly shaped branch cavities and single necks. The ASPMSS model is applicable to both symmetric and asymmetric resonators. In the present study, the ASPMSS model is extended to predict the sound reduction frequency of resonators with multiple necks. By applying the concept of equivalence, multineck resonators are transformed into equivalent models featuring a single wide neck. The enhanced ASPMSS analytical model is then used to determine the sound reduction frequencies of these equivalent models. Examples involving rectangular and cylindrical resonators are provided to validate the model. The sound reduction frequencies predicted by the analytical model are compared with simulation results from comsol 5.4. Additionally, the effect of model asymmetry on prediction accuracy is thoroughly examined. The comparison results from the examples demonstrate that the proposed enhanced ASPMSS analytical model is effective for resonators with multiple necks, regardless of asymmetry. Furthermore, the model exhibits excellent prediction accuracy and robustness.