• Title/Summary/Keyword: Submersed Body

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Numerical Calculation of the free-Surface Flows around a Submerged Body (잠수체 주위 자유표면 유동의 수치계산)

  • 김용직;하영록;홍사영
    • Journal of the Society of Naval Architects of Korea
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    • v.40 no.2
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    • pp.11-20
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    • 2003
  • In this paper, the high-order spectral/boundary-element method is developed to calculate the 3-dimensional water waves generated by a submerged body. This method is one of the most efficient numerical methods by which the nonlinear gravity waves can be simulated Tn time-domain. Three-dimensional free-surface flows generated by a submerged sphere which is moving under the free-surface are calculated. Through example calculations, nonlinear effects on free-surface profiles and hydrodynamic forces are shown. Comparisons with others' results show good agreements.

Performance Enhancement of Auto-Depth Control System for Submersed Body in Near Surface Environment (자유표면에서의 수중함 심도제어 시스템 성능 개선)

  • 이석필;윤형식;박상희
    • 제어로봇시스템학회:학술대회논문집
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    • pp.637-641
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    • 1991
  • One of the most difficult problems in depth control for underwater vehicle is the effect of seaway disturbance. When a underwater vehicle operates in a near surface environment, the seaway generates essentially two types of stochastic disturbances that influence the boat notion. One component of the seaway forces is of large magnitude with a relatively narrow-band, first order component. The other component is generally of somewhat smaller magnitude, second order component. Since the magnitude of the first order component is generally such greater than the compensating force that can be generating by the planes, it is undesirable for the controller to generate a control command. In this paper, we used LPC(Linear Predictive Coding) processing to uncontrollable seaway disturbance. This method can be used extensively in sensor signal processing of underwater vehicles.

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PIV Applications for Flow Analysis of Tetrapod and Artificial Reef (소파블록과 인공어초 주위의 유동 해석을 위한 PIV 적용)

  • Lee Gyoung-Woo;Jo Dae-Hwan;Kim Ho;Lee Seung-Keon
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • pp.141-146
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    • 2005
  • This paper an application example of PIV system for analyzing the flow of submerged structure. In this paper, we introduce an analysis method to predict the characteristics of flow around the neighboring fields of tetrapod and fishing reef in order to develop a high performance model. Flowing phenomenon according to velocity distribution and flow separation around the submersed body were obtained by PIV system. Flow visualization has conducted in a circulating water channel by a high speed camera and etc.

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