Learning Forum

[Louis Delait]

Hello all,

I am using the field calculator of Ansys HFSS 2023 to compute the power passing through a surface by implementing this equation:

where W = power [W] , P = Poynting vector [W/m^2] , integration is made on the surface "S".

Here is my issue:
While applying this equation on surfaces at increasing distances from the source in a lossy medium, I see the power decreasing as an exponential (which is the expected behaviour) until a certain distance where it seems to saturate at a value of 1e-5 [W]. I think this is due to numerical accuracy which is too low.

I therefore would like to increase the number of digits of the saved fields used in this computation.
Do you know any way to do so? 

Best,
Louis 

[Praneeth]

Hi Louis,

Thank you for reaching out to the Ansys Learning Forum.

Please share screenshot of the evaluated expression in the field calculator to help us serve you better. Generally, the accuracy in the field calculator is upto 15 places after the decimal point.

Best regards,
Praneeth.

[Louis Delait]

Dear Praneeth,

Thanks for the answer. Find below a matlab plot of the power values extracted from HFSS.

Following your comment, this 'saturation' observed on the graph above 6.5 [mm] shouldn't be due to the numerical accuracy?
Do you know where to change this setting in Ansys HFSS?

Best,
Louis

[Praneeth]

Hi Louis,

Yes, this saturation would not be because of the numerical accuracy. For confirmation, please check these field values in the field calculator before exporting them into Matlab.

Best regards,
Praneeth.