Learning Forum

[gordon]

Hi,

I am currently working with a 3D Maxwell Electrostatics simulation. The simulation basically consists of two flat parallel plates of size ~100 cm x 28 cm x 1.27 cm with a fixed voltage and I'm trying to measure the E-field between them. The difficulty comes when I put in a small cube with a voltage on one of the field plates to simulate the effect of an imperfection on them:

 

(You can see the small cube on the bottom field plate that I put in.)

If I make the cube smaller than about 1 mm, I cannot plot the mesh on the small charge (even though I can solve). It simply says, "Plot 'ChargeMesh' becomes invalid due to no available mesh." This message persists even when I apply a special Mesh Operation on the cube such that the length of the mesh is smaller than the size of the cube. Note that I've also set the Model Resolution (in Initial Mesh Settings) to Auto. Thus, even though I'm seeing some sort of effect in the E-field from the cube, there is no clear way for me to check if Maxwell is really properly meshing and taking the cube into account when solving.

[gordon]

Anyone have any ideas?

[gordon]

Anybody have any ideas? Still unable to plot it.

[Charlotte Blair]

Let's step back a bit and think about what you are trying to do. You want one of the metal plates to have some sort of "indentation" on it to see the effects of the Electric field. This is one of the strength of an EM tool to show you the behavior of the E/H field as you make geometry modifications that can not be based on an equations. You have the right approach - go ahead and create a box that represents your indentation and subtract it from your model geometry. Now go ahead an plot the mesh and you should see the cutout in the mesh view. I used your dimensions and a 1mm box and was able to see the difference in mesh with and without the box. Plot the Mesh by selecting the plate in 3D Modeler Window and Right Mouse Click > Plot Mesh. You don't have to fully analyze in order to see the Mesh just be sure to Generate the Mesh in the Analysis Setup. Now for your question - does this size make a difference in the field plot. Go ahead and parameterize the box cutout and you will see your answer. This is why we need an em simulator to see what changes in the field each of these physical changes make.