Photoacoustic Resonator

Application ID: 12435

This is a model of a simple photoacoustic (or optoacoustic) resonator. A pulsating laser heats a gas causing expansion and contraction and thus creates pressure waves. Such devices are used as sensors for measuring material parameters of the gas inside the resonator. The resonance frequency of the system depends on the gas in the resonator.

The model uses the Thermoviscous Acoustics, Frequency Domain interface with a heat source domain feature to include the heat generated by the pulsating laser. The thermoviscous acoustics interface is well suited for this type of application as it solves the full linearized equations for a compressible fluid including the energy equation.

The models is also set up using Pressure Acoustics, Frequency Domain to highlight the use of the Thermoviscous Boundary Layer Impedance boundary condition. This condition exactly mimics the losses in cases where the boundary layers are not overlapping.

This model example illustrates applications of this type that would nominally be built using the following products: