The Aeroacoustic Flow Source Coupling (
) is a unidirectional multiphysics coupling between an LES (large eddy simulations) or DES (detached eddy simulation)
Fluid Flow interface and the
Aeroacoustic Flow Source feature in the
Pressure Acoustics, Frequency Domain interface.
The coupling feature should be solved for in a separate study using the dedicated Transient Mapping (
) study. This step will map necessary data from the CFD source mesh to an acoustics mesh. Following the Transient Mapping a separate Time to Frequency FFT study has to be used to transform the flow source data from the time domain to the frequency domain. Then the Pressure Acoustics, Frequency Domain model is solved.
See Settings for further details about
Label and
Name.
The default Name (for the first multiphysics coupling feature in the model) is
afsc1.
If the Acoustic analogy option is set to
Lighthill (see below), select boundaries where the normal mass flow is mapped. This corresponds to sources generated by moving/vibrating boundaries in the flow simulation. If all boundaries are rigid no boundary selection is necessary.
Select the Source and
Destination physics. The source can only be an LES or DES fluid-flow physics interface and the destination the Pressure Acoustics, Frequency Domain interface.
Select the Acoustic analogy, used for the computational aeroacoustics (CAA) simulation, as
Lighthill (the default) or
Aeroacoustic wave equation. For the coupling to work the
Acoustic analogy selection in the
Aeroacoustic Flow Source has to match the options selected in the multiphysics coupling.
Select the Smoothing method as
Isotropic diffusion (the default) or
None. For the isotropic diffusion option set the (numerical)
Diffusion constant (the default:
1e-4). It is recommended to always use a small amount of smoothing to ensure smooth gradients of the background mean flow variables.