In this example, we are going to calculate the monostatic RCS of rectangular chaff with a frequency sweep using Domain Decomposition.
First, start newFASANT.
Select “File → New” (or, alternatively, press Ctrl+N), and select Chaff from the list of modules by clicking in the following button:
Chaff module button
Select “Geometry → Rectangular Chaff” and enter the same parameters as shown in the figure:
Rectangular Chaff Menu option
Rectangular chaff parameters and visualization
Select “Simulation → Parameters”, select a frequency sweep from 3 GHz to 5 GHz with 3 samples, as shown in the figure and press the “Save” button.
Simulation parameters (frequency sweep)
Select “Solver → Parameters”.Select the “Domain Decomposition” method and leave the default parameters. Press the “Save” button.
Solver parameters (Domain Decomposition)
Select “RCS → Parameters”. Select “Monostatic RCS” with the default parameters and press the “Save” button.
RCS parameters panel
Select “Output → Observation Directions” and introduce the far field observations as shown in the following Figure. Press the “Save” button.
Far Field Observation Directions
Select “Meshing → Create Mesh”.
Meshing → Create Mesh Menu option
Select 10 divisions in both planar and curved surfaces and the default frequency value. One processor should be enough for the meshing process. Press the “Mesh” button.
Select “Calculate → Execute”, choose the number of processors used to run the simulation and press the “Execute” button.
Selection of number of processors
When the simulation has finished (i.e. the text in the progress bar in the bottom-right corner of the window is “Done.”) we can see the results. Select “Show Results → Far Field → View Cuts” to show the RCS graphic:
Show Results → Far Field → View Cuts Menu option
RCS graph for the first sampled frequency (3.0 GHz)
As we see, only the graph for the results of the first sampled frequency is plotted. To compare the results for different frequencies, select the “4.0E9” frequency and press the “Add Series” button. Then, select the “5.0E9” frequency and press the “Add Series” button again. Now we can see the results for the three frequencies:
RCS graphic of all sampled frequencies
Select “Show Results → Far Field → View Cuts by Frequency” to visualize the relationship of the RCS values and the frequency:
Select “Show Results → Far Field → View Text Files”.
Show Results → Far Field → View Text Files menu option
Select one of the frequencies and press the “OK” button.
Far Field Text File panel
Visualizing results in text format