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Shock Waves

, Volume 24, Issue 1, pp 69–78 | Cite as

Background-oriented schlieren with natural background for quantitative visualization of open-air explosions

  • T. Mizukaki
  • K. Wakabayashi
  • T. Matsumura
  • K. Nakayama
Original Article

Abstract

This study describes an attempt of quantitative visualization of open-air explosions via the background-oriented schlieren method (BOS). The shock wave propagation curve and overpressure distribution were extracted from the obtained images and compared with the results of the numerical analysis. The potential of extracting the density distribution behind the shock front is also demonstrated. Two open-air explosions were conducted; one with a \(36\)-kg emulsion explosive and the other with a \(7.89\)-kg composition C4 explosive. A high-speed digital video camera was used with a frame rate of \(10{,}000\,\mathrm{Hz}\) and a pixel size of \(800 \times 600\). A natural background, including trees and grass, was used for BOS measurements instead of the random dots used in a laboratory. The overpressure distribution given by the passing shock was estimated from the visualized images. The estimated overpressures agreed with the values recorded by pressure transducers in the test field. The background displacement caused by light diffraction inside the spherical shock waves was in good agreement, except at the shock front. The results shown here suggest that the BOS method for open-air experiments could provide increasingly better quantitative and conventional visualization results with increasing spatial resolution of high-speed cameras.

Keywords

Background-oriented schlieren Explosions Explosives 

Notes

Acknowledgments

The authors thank Dr. Atsushi Abe of ITOCHU Techno-Solutions Corporation for his help and for lending his experience with AUTODYN numerical solutions. The authors also thank Mr. Michel V. Hopson of the Naval Sea Systems Command, U.S. NAVY for his insightful comments on our manuscript.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • T. Mizukaki
    • 1
  • K. Wakabayashi
    • 2
  • T. Matsumura
    • 2
  • K. Nakayama
    • 2
  1. 1.HiratsukaJapan
  2. 2.TsukubaJapan

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