Calculating Aircraft RCS
Altair Forum User
Altair Employee
Altair EmployeeHi All,
I need some help with FEKO and I will appreciate if somebody can help.
Basically I am using FEKO to calculate the RCS of an aircraft which I created in SolidWorks and I imported into FEKO as an IGES file. The following issues occur and I would be grateful if you could help me with them.
I attached a ZIP file with 6 figures mentioned below and also the simulation that I ran.
1- I attached a picture of a warning I get every time I import the geometry into FEKO (Figure called 'Warning when importing'). Is this warning okay?
2- I want to associate Aluminium with the geometry but I could not and I keep getting the following error:
Creating medium...
Error 16108: Aluminium - Label Aluminium is not unique. A unique case-insensitive label is required.
I could only associate a perfect electric conductor, any solution for this?
3- In the figure 'Plane wave' I am showing the direction of the plane wave, The blue arrow has to do with the theta angle, and the yellow with phi angle. Could you please explain to me how each of them works and how they affect the direction of the waves sent from the source.
Intuitively I thought that when the aircraft is flying then the signal would be sent from the bottom and in a simple situation I am assuming that at that instance the aircraft is exactly vertical to the source. Is this a reasonable prediction? How do I change the location of the signal?
Also I ignore the yellow arrow, how does that affect the signal? Finally I am leaving the magnitude and the phase as default setting as shown in the figure, correct?
4- I created a 3D pattern for the far field. What I understand from the far field is where these waves are received in the structure. Is this correct? And I understand from the 3D pattern is that the signal is going to hit the whole structure. Correct?
5- I attached a figure showing the setting I chose for the far field request (figure called Request- far field settings). In the advanced setting, is it necessary to tick 'calculate continuous far field data' ? Are the other settings okay?
6- I attached the results in the figure called 'RCS results - Contours' which shows the 3D pattern of the radiation. It seems as if only the nose point of the aircraft is receiving the signal.
I understand from this figure that the signal is sent as a single wave in the direction of the plane wave. In RCS application, do they send one single wave or multiple? Also how can I view how the signal is scattered in the structure of the aircraft itself?
7- I attached another figure of results called 'Results- RCS Cartesian plot' which has the change of the RCS with theta (of the plane wave). Could you please explain to me why the change in theta shows from 0 to 180 degrees.
Also I would like to calculate the overall RCS of the aircraft (as one number), how do I calculate that? Do I integrate the area under the RCS curve? Finally for the polar plot (figure 'Results- RCS polar plot') it only shows half the circle, and not 0 to 360.
Thank you so much.
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Answers
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Hi Asmaa Alyat
I would suggest that you contact FEKO Support for your region direcly. They would be able to assist.
feko_support@europe.altair.com
Kind regards,
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