Wires capacitive coupling

QuickField simulation example

Calculate electrostatic coupling between two perpendicular wires. See also parallel wires capacitance.

Engineering question
How to find capacitive coupling between perpendicular wires

Engineering answer
Set up a 3D QuickField Electrostatics problem for perpendicular wires and evaluate capacitive coupling from computed field results.

Typical applications
perpendicular conductors, wiring harness crossings, cable routing intersections

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Problem Type
3D Import model of Electrostatics.

Geometry

Spacing between wires b = 10 mm, wire 1 diameter d1 = 8 mm, wire 2 diameter d2 = 2 mm. Wire's length L = 200 mm.

Given

Task
Calculate mutual capacitance between wires.

Solution
To calculate capacitance we assign opposite electric potentials U to the wires: +1V and -1V. QuickField calculates electric field distribution and the total stored energy W. Electric capacitance then is C = 2*W / (ΔU)²

Results
Electric field energy W = 4.58 pJ, potential difference ΔU = 2 V.
Capacitance C = 2*4.58 pJ / 2² = 2.29 pF.

Electric field distribution around wires.

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