This article details the process of analyzing sound intensity data using Simcenter Testlab Software.
Open the Simcenter Testlab Sound Intensity Analysis software (Simcenter Testlab -> Testlab Acoustic -> Sound Intensity Analysis). If using token licensing, the Sound Intensity Analysis uses 31 tokens.
Open the project in which the measurements are contained.
Go to the “Intensity Analysis” worksheet.
Populating and viewing intensity results: Select the data on which to perform the analysis (Figure 1):
Under “Meshes” drop it down to “Selection”
Press the “Select…” button
In the pop-up window, select which mesh components to include in the analysis. In this example, only one component will be considered
Press “OK” on the table
Press the “Add” button to populate the “Functions” table
Figure 1: Populating the Functions table data.
The “M” in the table stands for measured while the “C” stands for calculated. For example, pressure and intensity are measured, while sound power is calculated.
Press on one of the cells in the “Functions” area. This will populate the displays to the right
Change the view from “Front/Back Display” to “Octave Display”
The letters F1, F2, F3, etc refer to ISO Field Indicators. These indicate the quality of the measurements and mesh and are explained in the online help.
Figure 2: Displaying sound intensity data.
Calculating and Displaying Acoustic Maps:
It is possible to calculate and display an acoustic map which will serve for visualization of the sound intensity data and for sound source localization.
To calculate the acoustic map (Figure 3):
In the “Frequency Bands” area, press the “Add all third octave bands” button (the red button). This will populate the table
Press the “Calculate Bands” button
Select a cell in the Frequency Bands table to populate the acoustic map on the geometry
The results will show on the geometry. It is possible to view the overall intensity/power or to view the results by octave band.
Figure 3: View sound intensity results by making a selection in the Frequency Bands table.
Other acoustic map options: It is also possible to calculate an acoustic map for:
A single FFT line
A band in the FFT
A single octave
Multiple octave bands
A sum of octave bands
The process is very similar to process any of the above map types.
This example will show how to calculate the acoustic map for a single FFT line.
To do so, first clear any previous results (Figure 4):
Clear the table of any results (if desired to start with a fresh table).
Figure 4: Clear the frequency bands table.
Then add more results to be processed (Figure 5):
Press the “Add single FFT band” button (or whatever mode is needed). This will cause the graph display to display the full intensity spectrum in Front/Back mode.
Use the cursor to drag to the desired frequency for analysis
Press the “Add Band” button
Select the cell in the table
View the acoustic map for a single frequency. This frequency value will be displayed in the geometry map.
Figure 5: Add data of desired type and frequency by making a cursor selection in the plot.
Save Results: After curating compelling results in the Frequency Bands table, it may be desired to save the acoustic maps (Figure 6):
Press “Save results…”
In the popup window, select the Section in which to save the results and name the folder
Check to save the acoustic maps. It is also possible to save the calculated 2D functions
“Save and Close”
Figure 6: Save sound intensity results.
In the Navigator worksheet it is possible to display the acoustic map results as well as any 2D results.
To display acoustic map results (Figure 7):
Open a geometry display by pressing the “Geometry” button
Drag and drop the entire “Geometry” into a Geometry display
Navigate to the acoustic map results in the tree
Drag and drop one of the maps onto the geometry
It may be necessary to right click in the display and change the view to “Sound map”
Figure 7: View sound intensity maps in the navigator by displaying geometry as well as a sound intensity map.
