Is the Z force Vector Component the same thing as the Poynting vector? Sir James Jeans' remarks on the Poynting Vector, 1933This extract is from the classic text, "The Mathematical Theory of Electricity and Magnetism", by Sir James Jeans, published by Cambridge University Press in the fifth edition of 1933. Page 519. quote..
The Poynting Vector "points" (pun unavoidable) in the direction of the flow (another word for flux) of electromagnetic energy from point A in space to a point B at some finite distance away. In a rotating magnetic field motor, the rotor component moves in response to a sinusoidal magnetic flux produced by an electric field oscillating in and through the Stator components of the motor. The magnetic flux in the stator cores is reversing polar directions when evaluating a single core, but rotating polar directions when evaluating all the stator cores cumulatively over the time of a single rotation period. Therefore the Poynting vector, if it could be used at all in describing the full cycle situation, would amount to an arc through the cross section of the Stator beyond the outer diameter of the rotor component, with the AB points at either ends of the arc exchanging places over each half cycle. This would mean that any points along the circumference of the stator assembly designated as, for example, point A as source at one end of the arc and point B as sink 90 degrees away in the case of a two phase (x=sine, Y=cosine) stator, would be arbitrary and phase dependent, because both A(source) and B(sink) would have to exchange positions every half cycle in order to retain their definitions! Not only that, but the ZForce Vector value in our description is material or particle dependent as to it's magnitude and effect. Magnets primarily effect ferrous metal structures, but not other kinds. The Poynting Vector is not element dependent as it is ordinarily defined in physics literature. Therefore: The Z force Vector Component involved in the study of rotating field electric motor systems is not the same thing as the Poynting vector. If there is another name for the ZForce vector in the literature, we are not aware of it. Jim Ostrowski
