I have the following situation:
1) I build 2 Plates for the capacitor in freecad and saved them in .step format.
2) I merged them in gmesh (see attached .geo file) and built a airbox aroud.
3) I simulated the Electric Potential of this setup
--> Until here, everything seems to be OK.
But now, I want to calculate the capacitance of this plate capacitor.
Therefore I activated the calculate capacitance matrix in the solver settings and added the capacitance body-nr. in the boundary conditions of GND and VDD.
But the calculated capacitance is wrong, because it gives me 1.6e-9F and the theoretical value with this 10mmx10mm plates in 1mm distance should be 8.854e-13F.
Code: Select all
StatElecSolve: Capacitance matrix computation performed (i,j,C_ij)
StatElecSolve: 1 1 1.64744E-09
StatElecSolve: Capacitance matrix was saved to file capatest.dat
ComputeChange: SS (ITER=1) (NRM,RELC): ( 0.65536916 2.0000000 ) :: electrostatics
WritePostFile: Saving results in ElmerPost format to file ./case.ep
ElmerSolver: *** Elmer Solver: ALL DONE ***
ElmerSolver: The end
SOLVER TOTAL TIME(CPU,REAL): 0.23 0.23
ELMER SOLVER FINISHED AT: 2016/06/24 15:48:50
See the attached files for inspection
Regards,
Matthias