FDTD simulation of the acoustic interaction between a cavity and an adaptive Helmholtz resonator

Helmholtz resonators are used to manipulate the eigen behaviour of the acoustic fluid in a cavity. Using the analogy to a mass damper, it is possible to tune the resonators' eigen frequency by handling the resonator volume as spring and the resonator neck as mass of a vibration absorber. Simulating the transient interaction of the HR with the acoustic sound field in a cavity in terms of active sound control, a high simulation performance is demanded. This can be provided by the finite difference time domain method. The simulations are performed with respect to the LOEWE-Zentrum AdRIA acoustics demonstrator. It depicts the abstraction of a real room. Therefore, it consists of six sound reflecting walls that are implemented through acoustic impedances in the time domain. The semi-passive system is implemented using MATLAB/Simulink. In addition, the simulations are validated applying an adaptive Helmholtz resonator inside the acoustic fluid of the acoustics demonstrator.