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Admittance calculation in AC/DC

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Hello,
i m trying to calculate the admittance of my 2d model, which is a simple model to represent a body by a rectangle which two capacitors(also rectangles) attached one both sides. sinusoidal voltage is applied to the one and other one is grounded.
when i calculate the admittance (Y_ges) the real part differs from the one comsol calculates (ec.Y33). i see the whole body as capacitor parallel to a resistance, as well as the capacitors themselves (with R1=0 almost).

the formulas for the resistance and capacitance:
R=l/(sigma*A)
C=eps_0*eps_r*A/d
which is for 2d case in my model R=d/(sigma*b)) and C=eps_0*eps_r*b/d

b_b and d_b for the body and b_cap and d_cap for the capacitors.

Y_b as the body admittance
Y1 as the admittance of the both capacitors, cause there have the same properties:
Y11=jwC1+1/R1 (where C1 is the capacitance covering since its 2d)
Y1=Y11^2/(2*Y11)

i thought that i didnt make a mistake within the calculation, but maybe i missed something? help would be greatly appreciated.i hope its understandable. i attached the model.
under derived values in global evaluation the results are shown and compared. Y_ges should be equal to ec.Y33


i have issues uploading the files independant of the size it tells me: file extension error
i uploaded the file here: ufile.io/2hg10

thank you in advance
Hannes

0 Replies Last Post 30 mai 2017, 12:24 UTC−4
COMSOL Moderator

Hello Hannes Hinkelmann

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