Eddy-Current Reaction with Magnetic Field Produced by Helical Rotor

The use of the expression E = B X v has been shown by experiment to produce erroneous results when applied to the analysis of a system consisting of a hollow conducting cylinder coaxial with a helical rotor which carries windings producing a radial magnetic field. The expression predicts that no axial force can be produced on the cylinder. Tests with a helical-rotor electro-magnetic pump show this prediction to be false.