Journal of the Korea Institute of Military Science and Technology (한국군사과학기술학회지)

The Korea Institute of Military Science and Technology (한국군사과학기술학회)
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Prediction and Verification of Water-entry Traces Size of Small Falling Objects into the Sea

해상 소형 낙하물 입수흔적의 크기 예측 및 검증

  • Min, Anki (The 1st Research and Development Institute, Agency for Defense Development) ;
  • Hwang, Tae-Won (The 1st Research and Development Institute, Agency for Defense Development)
  • 민안기 (국방과학연구소 제1기술연구본부) ;
  • 황태원 (국방과학연구소 제1기술연구본부)
  • Received : 2014.07.25
  • Accepted : 2015.02.27
  • Published : 2015.04.05
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Abstract

An unmanned aerial photography method by using an unmanned helicopter is useful method for measuring of the water-entry traces of small falling objects into the sea. Pixel sizes on the aerial photograph may be too large due to a limit of camcorder resolution and a wide shooting area. If the pixel size is too large, identification of water-entry trace is impossible. Thus an accurate prediction of water-entry trace size is required. The traces of water-entry could be classified into three types such as splash, water column, and bubble. Diameters of each trace are predicted by water-entry impact pressure theories, cavity theories, and trial test results. The results are verified by drop tests using an unmanned helicopter at two water-entry speeds. As a result, prediction and test results showed sufficient similarity to evaluate the identifiability of water-entry trace.

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References

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