An Experimental Study of Electromagnetic Lorentz Force and Rail Recoil

Abstract

Understanding whether recoil forces are seated in the rails of any electromagnetic launch technology, including railguns, is critical for efficient development and design. Several theoretical and experimental researchers have produced multiple published papers characterizing rail recoil. These papers are not definitive and often conflict. An experiment has been developed that allows for the simultaneous measurements of the quasistatic Lorentz force on the armature and rail recoil. The primary challenge in quantifying these forces is removing the mechanical coupling required to construct the necessary circuit while maintaining electrical connectivity. Liquid metal Ga/In eutectic was used to conduct electricity while mechanically decoupling the rails from the rest of the circuit. Force measurements show that the force on the armature increases as the square of the current while the indicated reaction force on the rails is an artifact of the experiment. These recoil forces measured <1% of the force on the armature. We conclude that the recoil, or corresponding equal and opposite reaction force to the force on the armature, is not seated in the rails.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 2009
Accession Number
ADA514371

Entities

People

  • Michael J. Putnam

Organizations

  • Naval Postgraduate School

Tags

Communities of Interest

  • Energy and Power Technologies
  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Armatures
  • Artifacts
  • Charged Particles
  • Electricity
  • Electromagnetic Fields
  • Instrumentation
  • Liquid Metals
  • Liquids
  • Load Cells
  • Lorentz Force
  • Magnetic Fields
  • Measurement
  • Military Research
  • New Mexico
  • Resistance
  • Steady State
  • Three Dimensional

Fields of Study

  • Physics

Readers

  • Plasma Physics / Magnetohydrodynamics
  • Systems Analysis and Design
  • ballistics.