Dsp4

I have try different shapes with femm software and each time when a force move the piece of iron the energy in capacitor go down. Except at the case in the file, it's a circular capacitor and a half cage of iron. When the cage move it give energy and the charge of capacitor go down, so the energy go up. Do you know Femm software and help me to find my error ? I give first file for start position and second file for end position. Femm files.zip

Hi, Two surfaces are at 5 mm, the dielectric is an iron piece of 4 mm and 0.5mm of air. I put 100 V at two surfaces (like a capacitor), when the capacitor is charged I cut voltage source. Now, I would like to calculate the fields at surface iron piece and the charge in it. How can I do ?

If circles don't turn this give friction and it's difficult to calculate, that's it ? For now, all turn at W rd/s (circles, wall, gas). It's easy but how can I do ?

I'm interesting in physics, I'm not an expert I need help in some fields when I question me about something, I'm from France

Hi, The drawing show what I want to study. A gas (temperature T, pressure P when W=0 rd/s) rotating at W rd/s, the gas apply force on each surface of each green wall, this force give a torque. Sure, torque cancel itself from opposite surface. I would like to calculate this torque function of r1, r2, W, D, P, T, thickness ? How can I do ?