Thermoacoustics Simulation for More Robust Microphone Analysis
When performing an analysis on small-scale audio equipment, such as hearing aids, cell phones, and microphones, the obvious physical phenomenon that’s analyzed is pressure acoustics. However, there are other physics interactions that significantly affect these small devices, including electromechanical interactions and viscothermal losses. Most notably, thermoacoustics (the detailed modeling of acoustics including thermal conduction and viscous losses) is an often overlooked effect that can alter the results of a model. These effects are important in all devices with small length scales. The Brüel and Kjær 4134 Condenser Microphone model is a perfect example of these multiphysics interactions, with four different physics interfaces (Thermoacoustics, Membrane, Electrostatics, and Moving Mesh) used to model the sensitivity level, membrane deformation, pressure, velocity, and electric field of a condenser microphone.