Two disc capacitor - QuickField simulation example
Plane capacitor with two disc-shaped plates. This problem may be simulated in both 2D axisymmetric and 3D extrusion formulation.
How to find capacitance of two disc capacitor plates?
Answer Typical applications Geometry 2D axisymmetric/3D extrusion.
a = 2.4 mm, d = 0.1 mm.
Given
Task
Solution
QuickField simulation gives energy W and electric potential U distribution. The capacitance then can be calculated as C = 2W / ΔU².
Results * http://chemandy.com/calculators/circular-capacitor-calculator.htm
Engineering question
Set up a 3D QuickField Electrostatics problem for two circular capacitor plates and evaluate capacitance from computed field results.
disc capacitors, circular plate capacitors, parallel disc electrodes
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Simulation problem
Problem Type electrostatics.
Relative permittivity of air ε = 1,
Relative permittivity of media ε = 2,
Potential difference ΔU = 1 V
Find the capacitance of two disc capacitor.
Analytical solution gives the capacitance value of two disc capacitor as
C = ε·ε0·πa² / d + ε·ε0·a·(ln[16π·a/d] - 1), [F]. *
Analytical solution: C = 2·8.854·10-12·3.142·0.0024²/0.0001 + 2·8.854·10-12·0.0024·[ln(16·3.142·0.0024/0.0001) - 1] = 3.205·10-12 + 0.259·10-12 = 3.464·10-12 F.
Energy W
Capacitance C
2D axisymmetrical simulation
1.67e-12 C
3.34e-12 F
3D extrusion simulation
1.67e-12 J
3.34e-12 F
2D electrostatics simulation
3D electrostatics simulationRelated examples