• Title/Summary/Keyword: Veering Error

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Error Analysis Study on the Veering of Marine Target and the Midcourse Guidance of Anti-ship Missile (해상표적의 변침과 대함유도탄의 중기유도 오차분석 연구)

  • Kim, In-Soo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.23 no.6
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    • pp.582-590
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    • 2020
  • This paper presents the results of new error analysis on the veering of marine target with the concept of frequency of occurrence, and shows how to apply the midcourse guidance errors of anti-ship missile. The veering error would be a dominant factor in the midcourse guidance errors with flight time increase. This study suggests the reasonable application method of the veering error based on the characteristics of abnormal error, and describes the tailoring method including trade-off between the midcourse guidance range of veering target and the value of frequency of occurrence on veering error.

Surface pressure measurements in translating tornado-like vortices

  • Kassab, Aya;Jubayer, Chowdhury;Ashrafi, Arash;Hangan, Horia
    • Wind and Structures
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    • v.33 no.6
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    • pp.447-462
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    • 2021
  • High spatial and temporal surface pressure measurements were carried out in the state-of-the-art tornado simulator, the Wind Engineering, Energy and Environment (WindEEE) Dome, to explore the characteristics of stationary and translating tornado-like vortices (TLV) for a wide range of swirl ratios (S=0.21 to 1.03). The translational speed of the TLV and the surface roughness were varied to examine their effects on tornado ground pressures, wandering, and vortex structure. It was found that wandering is more pronounced at low swirl ratios and has a substantial effect on the peak pressure magnitude for stationary TLV (error percentage ≤ 35%). A new method for removing wandering was proposed which is applicable for a wide range of swirl ratios. For translating TLV, the near-surface part lagged behind the top of the vortex, resulting in a tilt of the tornado vertical axis at higher translating speeds. Also, a veering motion of the tornado base towards the left of the direction of the translation was observed. Wandering was less pronounced for higher translation speeds. Increasing the surface roughness caused an analogous effect as lowering the swirl ratio.