General Signal Processing (GSP) Tool

Overview

ultraFluidX provides an option for aeroacoustics post-processing with a dedicated post-processing capability included in ultraPostX.

Use ultraPostX

The GSP post-processing tool requires ultraFluidX input data in .h3d format. Suitable inputs are surface data files generated by ultraFluidX.

Launch the tool

The ultraPostX tool can be launched in the command line by calling the executable (location depending on installation) and providing the name of an input deck:

>> ultrapostx input_deck.xml

ultraPostX outputs

The GSP post-processing tool produces .csv and .h3d outputs as requested by you.

Simulation Parameters

The ultraPostX tool uses an .xml file to specify all required parameters:

<gsp>

This section details information about surfaces included in the calculation, using the general signal processing workflow.

<surface_instance>

For each surface, a separate instance can be requested:

<name>: Name of the surface instance.
<output_path>: Path of the output folder.
<input_file>: Input file that contains h3d surface data.
<parts>: List of all of the parts that are to be considered, each indicated by their name.
<hydro_dbmaps>: [true, false]; Requesting a .h3d output file for hydro dB maps.
<acoustic_dbmaps>: [true, false]; Requesting a .h3d output file for acoustic dB maps.

This section details parameters for the flow simulation and signal processing:

<fluid_simulation>

This section summarizes the flow parameters, which should be in agreement with the original ultraFluidX simulation that is used as an input.

<wind_tunnel_speed>

Mean flow velocity in [m/s].

<mach_ratio>

Mach factor.

<material>

Material properties.

<specific_gas_constant>: default 287.058; Specific gas constant of the fluid in [J/kgK].
<reference_pressure>: default 2e-5; Reference pressure in [Pa].
<temperature>: default 293.15; Temperature of the fluid in [K].
<specific_heat_ratio>: default 1.4; Specific heat ratio of the fluid.

<signal_processing>

Parameters used in the signal processing step:

<block_size>

default: 2048

<block_overlap_percentage>

default: 50.0

<start_time>

Start time of processed signal in [s]. The default auto uses the first timestep of the input data.

<end_time>

End time of processed signal in [s].

<band_type>

[broadband, narrowband] default: broadband.

<octave_band_order>

Octave band order for broadband calculations [1,3,12] default: 3.

<min_frequency>

Lower frequency limit for processing in [Hz] default: 100.

<max_frequency>

Upper frequency limit for processing in Hz default: 10000.

<windowing>

Details on time windowing with sub parameters:

<time_window>

<type>: [uniform, hanning] default: uniform

<hydro_dbmaps>

Parameters controlling hydro dB map output:

<start_time>: [auto; time in s]
<end_time>: [time in s]
<band_type>: [broadband, narrowband] default: broadband.
<octave_band_order>: Octave band order for broadband calculations [1,3,12] default: 3.
<min_frequency>: Lower frequency limit for processing in [Hz] default: 100.
<max_frequency>: Upper frequency limit for processing in Hz default: 10000.

<acoustic_dbmaps>

Parameters controlling acoustic dB map output:

<start_time>: [auto; time in s]
<end_time>: [time in s]
<band_type>: [broadband, narrowband] default: broadband.
<octave_band_order>: Octave band order for broadband calculations [1,3,12] default: 3.
<min_frequency>: Lower frequency limit for processing in [Hz] default: 100.
<max_frequency>: Upper frequency limit for processing in Hz default: 10000.