Discussion Forum

I am brand new in Comsol and I am trying to design a capacitor to study the behavior of the electric field inside and around it by applying AC current. I designed my capacitor in Comsol multiphysics version 5.5. For the preliminary design and learning the Comsol, I considered my device such that:

• Physics: AC/DC --> Electric Fields and Currents --> Electric Currents (ec)

• Study: Frequency domain

• Geometry and Materials: My capacitor contains two parallel plates with the size of 3002002 mm^3 built with FR4. As a conductor, two copper plates with the size of 200281, electrical conductivity= 5.8e7 S/m, and relative permittivity= 3e5 are considered. All the design is considered inside the sphere built of air with electrical conductivity= 1e-24 S/m, and relative permittivity= 1.0006. It means that the space between the plates is also filled up with air.

• Electric Current: As a terminal, I chose an upper copper plate in V0= 5V, and as a ground the lower plate

• Mesh: Finer

• Study1: Steps1 --> study setting --> frequency unit=kHz with range (10,10,200)

Questions:

1. In the Electric Currents(es), in the Manual Terminal Sweep Settings, do I need to select the check box “Use manual terminal sweep”? why yes or no?

2. Why in the electrical current for the Terminal, just shows Domain, not boundaries and…?

3. Results section --> both Multislice and Surface --> expression --> replace expression --> I chose ec.normE. But in this section, there are two types of electric filed EX, EY, EZ, and Ex, Ey, Ez. What is the difference between these three types of electric fields? Is it correct my choice as ec.normE?

4. I am not sure if my results are correct or not

For more help, I uploaded the simulation which I designed. Thanks in advance.