http://www.blazelabs.com/e-exp10.asp
"The dielectric area [CD ROM area] just above the spheres [pipe stators in my disk motor] gets polarized and locally charges up with the polarity of the terminal. Since the aluminum foil on the upper surface is at half the hv potential, this generates an asymmetrical field beween the sphere and the disc, which accelerates the charging up process, by accelerating charged air ions onto the face of the disc [corona discharge]. Since the disc is made of insulating material, the charged dielectric particles cannot move over the surface of the disc without the disc itself moving, so a force from the pisitively charged dielectric area is generated toward the negative sphere, and a similar force from the negatively charged dielectric area is generated toward the positive sphere, thus creating a moment [the torque to rotate the disk]. Charges are thus continuously carried from one side to the other, the higher the revs, the more charges are carried, and this is reflected in a linear increase in current consumption with speed of rotation."
There are still many aspects of motors where I think we are speculating without hard evidence. It would be nice if we had access to diagnostic tools that would work at small distances over small areas. How great it would be if we could see the generation of negative and positive ions in the air between the the stator and rotor, and then watch the subsequent motion of the ions and their deposition on the rotor. Scientists have observed the spectra of corona discharges, and identified the presence of negative and positive ions of molecular nitrogen and oxygen. It would be interesting to know the lifetimes of these ions as they reside on dielectric of the rotor. For example, we know that our motors reach a limiting value of rotation, which is probably set by both the lifetime of the ions, as well as the rate of ionization of the air by the corona discharge.
But all things considered, it is quite fascinating how much we can deduce about our motors simply using our eyes and ears to sense the presence of the corona discharge, which seems so necessary for our motors to run. We could of course nail that down if we could put Dirod and a motor in a vacuum chamber. If we are correct, the motor would simply not run in a vacuum.