Abstract
In this article, an innovative and comprehensive model is proposed to predict the sound reduction frequency of asymmetric side-branch resonators. This analytical model, referred to as the analogy serial-parallel mass-spring system (ASPMSS) model, incorporates the concept of serial-parallel mass-spring systems into the analogy mass-spring system (AMSS) model. The side-branch resonator is modeled as two parallel effective mass-spring systems, with the sound reduction frequency equal to the natural frequency of the two effective parallel mass-springs. The proposed model is capable of predicting the sound reduction frequency of asymmetric branch cavities with random shapes, as well as symmetric branch cavities as a special case. Several simulation and prediction examples are presented, and the sound reduction frequencies calculated by the analytical model are compared to simulation results from comsol 5.4. The comparison results show that the proposed ASPMSS model is applicable to side-branch resonators with asymmetric geometric profiles and has a high level of prediction accuracy and robustness.