The resulting equation is nonlinear and therefore does not allow the application of the superposition principle. In particular, the Background Pressure Field (for Transient Models) cannot be defined together with the Nonlinear Acoustics (Westervelt) feature.
|
The presence of the Nonlinear Acoustics (Westervelt) node changes the default solver settings for the proper treatment of nonlinearities. It is therefore required to Reset Solver to Defaults whenever the feature is added to or removed from the model.
|
The frequency spectrum of a nonlinear wave model contains not only the center frequency f0 but also the harmonics N·f0, N = 1,2,3,… generated. The Maximum frequency to resolve in the Transient Solver Settings section should be specified to resolve a desired number of harmonics to achieve a certain precision. This is especially important for shock waves, where the number of harmonics to resolve can exceed 10.
|
•
|
For the option From parameter of nonlinearity enter the value of the Parameter of nonlinearity, B/A. The coefficient of nonlinearity is defined as follows
|
•
|
For the option From ratio of specific heats (for gases) enter the Ratio of specific heats, γ. This option is valid for perfect gases under isentropic conditions. Here,
|
•
|
Nonlinear Acoustics — Modeling of the 1D Westervelt Equation: Application Library path Acoustics_Module/Nonlinear_Acoustics/nonlinear_acoustics_westervelt_1d
|
If the chosen fluid model has no dissipation (Linear elastic (the default) or Ideal Gas), a default sound dissipation δ = 2·10-5 m2/s will be used in the artificial damping term.
|