Simulation Parameters

The root element indicates the version number of the FW-H tool:

<fwh version="2024.1.0">

This entryis parent to all other elements in the file, so the file must always end with </fwh> according to XML standards.

The organization of parameters into categories is detailed below.

<input_files>

This category indicates which ultraFluidX input files are used as input to the FW-H calculation:

<name>: Specifies the path to one or several H3D and/or EnSight files containing partial surface or monitoring surface output generated by ultraFluidX. For unmerged data, an .sos file or a list of RANK *.case files need to be provided. For merged data, the .case file is specified.

<general>

The <general> section allows to specify the FW-H formulation:

<formulation> [porous, solid] default: porous: The user can to indicate whether the porous or solid formulation of the FW-H analogy is to be used (if no setting is provided, porous will be used as default). Note that the input data needs to correspond to this setting, i.e. the porous formulation uses pressure and velocity data sampled in the volume field on a monitoring surface, while the solid formulation is based on pressure data sampled on a partial surface.

<material>

This section contains the material properties of the fluid. Note these quantities need to correspond to the values that were used in the original ultraFluidX calculation. If not specified, the values for <temperature>, <specific_gas_constant>, and <specific_heat_ratio> will use the default values of ultraFluidX as indicated below. The values do therefore only need to be specified if the ultraFluidX run did use different settings (e.g. another fluid temperature).

<temperature>: (optional, default value= 293.15); Fluid temperature in [K].
<specific_gas_constant>: (optional, default value = 1.4); Specific heat ratio of the fluid.
<reference_acoustic_pressure>: (e.g. 2e-5); Reference pressure value in [Pa] used for OASPL calculation.

<reflection_plane>

The FW-H tool can account for absorbing reflection planes in the domain. One plane in each direction (global x-, y-, z-) can be defined and requires the following parameters, for planes [<x_direction>, <y_direction>, <z_direction>]:

<active>

bool: true or false

Indicates whether this plane is considered or not.

<position>

floating-point value

Indicates the position on the respective axis (i.e. x-axis in this case) Note that all coordinates are in [m].

<absorption>

floating-point value between 0 and 1

Indicates an absorption value for the plane:

Fully rigid plane: absorption = 0
Grass: absorption ≈ 0.6
Fully absorbing material: absorption = 1

<probe_output>

<name>: Indicates the name of the pressure signal output files. The file name in the output folder will be followed by one of two tags, sync or notsync. The sync tag refers to signals using a global reference time and contain leading or trailing zeros (i.e., times when no signal is recorded at the respective receiver). notsync refers to signals using a local reference time, containing only the usable part of each receiver's signal.
<microphone_locations>: <name>; One or several .csv files which indicate microphone coordinates.
<output_path>: Indicates a folder where the results of the FW-H tool are written.