Discussion Forum

I am trying to design a simple parallel plate capacitor model into which I plan to introduce further complications later on for a sensor. Thus far, I have created the model and plotted the electric field, but have not been able to calculate the capacitance.

My model is enclosed in a cylinder of air with two smaller (shorter) cylinders of copper. One is grounded, and one has a terminal voltage of 10V.

Here are my questions/hesitations with my current model (attached):

1. Voltage surface plot seems incorrect and only is plotted on only one surface apparently.

2. E-field lines appear inside of the copper, but not much on the outside. There shouldn't be field lines in the conductor, and I want to be able to see the lines in between the plates.

3. (Most importantly) When I try to calculate the capacitance using the global evaluation, the program yields an error that there is "No Stored Reaction Force data."

Some things I have read in the documentation and this forum suggested to me these things could contribute to the errors:

1. Calculation of reaction forces (I have the box in the solver checked already). Is there an additional parameter/solution I must calculate?

2. I have read things about internal boundaries being messed up if they are within another structure (e.g. my cylinder of air), but haven't seen a solution or an option to turn them on/off in version 4.2.

Thanks for the help--still trying to figure out the nuts and bolts of the program, and sometimes the documentation doesn't answer all of my questions.