Effect of Electromagnetic Fields on the Stability of a Perfectly Conducting, Axisymmetric Shaped-Charge Jet
Final rept. Jan-Sep 1989
ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD
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The stability characteristics of a shaped-charge jet which carries an electrical current are investigated. The jet is assumed to be perfectly plastic, perfectly conducting, and axisymmetric. The equations which govern the behavior of the jet are solved numerically using first-order perturbation theory, after the surface of the jet has been subjected to some arbitrary disturbance. The solution of these equations indicates that the jet is unstable. The growth rate of the instability depends upon the relative importance of inertial, electrical, and plastic forces, and upon the size of the disturbance wavelength relative to the jet radius. It is argued and demonstrated from the numerical solutions that the electromagnetic forces always make the jet more unstable than it would be in their absence. Application of the theory suggests that electromagnetic fields may be capable of enhancing jet breakup on a time scale of practical interest, but more work, both theoretical and experimental, needs to be done before definite conclusions can be drawn. Keywords Shaped charge jet Metal jet Jet Stability MHD Stability Electromagnetic disruption.
- Electricity and Magnetism