Simulation based study of magnetic velocity induction system by using Analysis System Electromagnetics Suite

Rev Sci Instrum. 2021 Sep 1;92(9):094708. doi: 10.1063/5.0050383.

Abstract

The magnetic velocity induction system (MAVIS) is commonly used for velocimetry in shock compression experiment. Due to some discrepancies, the variation in induced voltage amplitude is ambiguous, which makes the simulation of this experiment particularly significant. In this work, we have designed a MAVIS, which was used to determine the induced voltage amplitude and flyer velocity. We built a three-dimensional model of MAVIS and performed the simulations using the Analysis System Electromagnetics Suite. Additionally, we performed some experiments and compared the results of both studies on the basis of flyer thickness, radius, and velocity. It was established that the flyer velocity influenced the induced electromotive force (EMF) in the pick-up coils. The increase in flyer radius led to the increase in the induced EMF. The cut-off radius for flyers was also discussed in detail by computing the lowest induced EMFs at discrete flyer velocities and radii. Due to the eddy current loss, experimental data laid slightly lower than simulations. The simulation data have proved its accuracy within the experimental error range. Thus, it can be applied as an economical framework to calculate projectile velocity precisely, regardless of its geometry, and to estimate the trigger level of the oscilloscope before performing the experiments. In order to enhance the quality of induced voltage, we also proposed a new design consisting of three pick-up coils. This redesigned MAVIS contributed significantly in signal narrowing as well as controlled the loss in amplitude peaks that reduced the experimental uncertainty in flyer velocity <0.4%.