Terry, Thanks for the SPRAIN update. Very informative.
As a matter of public disclosure: Years ago I performed thousands of Finite Element Method Magnetic (FEMM) computer simulations on various PM configurations for a start-up company which at the time was actively exploring the matter. (This was not SPRAIN related.) As far as my own 2-D simulations were concerned no OU was ever discovered even though some of my simulations appeared to show that OU existed. In another case I got confused about a certain interpretation pertaining to "tensor field" forces and I ended up grossly miscalculating the torque strength. (For a while I really thought I was on to something huge!) The final conclusion that most in the company arrived at was the fact that the 2D FEMM software I was using was not sophisticated enough to compensate for certain mathematical anomalies introduced into the calculations. Certain anomalies seemed to get magnified based on specific geometries and angles being simulated. Over time tiny little errors/anomalies have a tendency to accumulate into one very big error. It was as if thousands of rounding errors accumulated and falsely ended up giving a huge OU signal where none actually existed. I learned a lot performing those FEMM simulations. It was also a very humbling experience. Terry, I don't think we ever discussed the following matter off line, but this is the conclusion I have come to in regards to potential OU permanent magnet motor configurations. It seems to me that one theoretical form of PM OU might still have a fighting chance of being for real IF PM magnetic fields can be influenced or manipulated in such a manner as to cause a cyclical variability in the magnetic field's strength. The problem that always seems to crop up, at least as I see it, is the fact that PM forces are essentially STATIC. Because magnetic forces are STATAIC there is never any variability (or asymmetries) that one can manipulate. If a methodology could be initiated that essentially manipulates a PM's magnetic field's strength WHERE THE PMS MAGNETIC FIELDS VARY CYCLICALLY IN STRENGTH, I believe an authentic OU configuration is possible. How strong? I dunno. I suspect this is where gnarly and obtuse discussions pertaining to harnessing the characteristics of "magnetic viscosity" enter the discussion. (It's possible Steorn may have been exploring viscosity at one time.) Some suspect acquiring a better understanding of viscosity, and learning how to manipulate those magnetic migratory paths IN A CYCLICAL MANNER might introduce in certain PM configurations sufficient asymmetries that one could take advantage of. Again, I dunno. The FEMM software I was using was totally incapable of modeling viscosity characteristics. Thus ended my theoretical research into the matter. Alas, I would have loved to have continued further explorations on the matter. Regards "Professor" Johnson www.OrionWorks.com www.zazzle.com/orionworks
