Study On Aluminum - Based Combined Electromagnetic Particle Velocity Meter Matching With Impedance Impedance

A multiple electromagnetic particle velocity gauges package, well matched with the impedance of explosives, is manufactured. By using multiple electro-magnetic particle velocity gauges method, particle velocities of inert materials and energetic materials are obtained accurately together with the shockwave tra-jectory. The gauge package consists of three "shock tracker" and eight particle velocity gauges, whose lengths varies from 5 to 12 mm. The gauge package is made from 10μm aluminum foil covered with two 20μm polyimide films. The magnetic field is provided by a permanent magnet, avoiding the disturbance caused by large current. The design strength of the magnetic field is 7.50×10-2T, with a≤1% deviation of the magnetic field in the central cube.Particle velocities of PMMA and JOB-9003 under different initial shock loading are recorded by using the multiple electromagnetic particle velocity gauge method. The Hugoniot relation of PMMA is obtained by linear fitting the shock-wave velocity with particle velocity. The shock initiation of JOB-9003 is analysed qualitatively.The constrained least squares method is used to fit the shockwave trajecto-ry data of JOB-9003 with Hill’s function. The run distances of JOB-9003 under different initial pressure are calculated. The pressures and specific volumes at different lagrangian position are calculated by using lagrangian analysis method.The shock initiation process of JOB-9003 is simulated one-dimensionally by using DYNA2D program. The calculated particle velocity is compared with the experimental data. JWL equation of state(both the unreactive explosive and product) and Lee-Tarver reaction rate model are applied in simulation.