Output characteristics of explosively-driven ferromagnetic generators

Output characteristics of explosively-driven ferromagnetic generators based on NdFeB magnets were investigated by varying design features. The length of magnets was changed from 20 to 60 mm, and the pitch of pulse generating coils was varied from 0.5 to 3 mm. In each test, a magnet was impacted by a conical aluminum flyer plate with an average thickness of 2.83 mm at a velocity of 2.1 m d p . The open and load voltages were nearly constant for the same pitch, -460 V (open) and -205 V (load) at 1.0 mm pitch, respectively. The current varied from 90 to 250 A. The energy output was the highest when the inductance of the load was matched to that of the coil. Results from twodimensional hydrodynamic calculations agreed qualitatively well with experimental results, and demonstrated that the two-dimensional effects could not neglected in analysis of experimental results.