In this section, a simple example of a Near Field simulation will be shown. This simulation will be performed considering a cube as the geometry. An Ultrasound Source will be defined as an ultrasound pattern file (also called DUS files).
Step 1. The first step consists of creating a new data file where all the parameters of the simulation will be saved. Use the command ‘New’ from the File menu. Select US type.
Selection Method dialog box
Step 2. The second step is to generate the box. Select Geometry→ Solid → Box. It will be located at (0,0,0) and the dimensions are 1x1x1 m.
Box situated at (0,0,0)
Step 3. The next step is to set the main parameters of the simulations, which are located in Simulation Parameters Menu → Simulation.
A dialogue box appears. In this menu, the frequency, kind of simulation, speed of sound sweep, effects to calculate, and other parametersmust be defined before running the simulation. In this example, a radiation pattern file in far field is simulated. The user will introduce:
· Near field in Simulation Type.
· The number of frequency points and the frequency: in this example 1 and 50 KHz.
· The Speed of Sound Sweep will be 340 m/s
· The effect order will be 1.
The rest of the options are the default ones.
Parameters dialog box
In this case, an omnidirectional pattern file has been edited.
DUS file Editor
Step 4b.Import the ultrasound pattern (DUS file) to the current project. In this example, the user has to import the demo_DUSfile.dus DUS file.
Import DUS file
Step 5. Define the position of the ultrasound pattern over the cube clicking on Source →Ultrasound Pattern.
Set the ultrasound pattern file. Click on the add button and add the preious imported file.
Set the Amplitude and phase.
Set the position of the source on (0.5, 0.5, 1.2).
Ultrasound Pattern menu
Step 6. The next step is to define the position of the observations points. Select Observation points from Output menu. In Geometry Types dialog, select Plane and click on the Add button.
Step 7. To mesh the geometry click on Meshing → Create visibility matrix and select the number of processors.
Processors option for meshing
Step 8. Execute the simulation by selecting Calculate → Execute and introduce the number of processors to be used.
Processors options for Execute
Step 9. After obtaining the results, choose view ray from show results. It is possible to visualize order 1 rays.It is possible to represent the ray tracing interacting with the geometry.
Ray Viewer dialog box
Step 9. It is possible to select a ray to show its information. Clicking in one of the ray will fill its information in the bottom of the panel.
Viewing the ray information
Step 10. To visualize the charts click on Show Results →Near Field →View Cuts, after which the following dialog will be shown: