Journal of Navigation and Port Research (한국항해항만학회지)

Korean Institute of Navigation and Port Research (한국항해항만학회)
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An Experimental Study on the Slamming impact around Wedged type structure in accordance with the Weight and Height of the change

중량 및 높이변화에 따른 쐐기형 구조물 주위의 슬래밍 충격에 관한 실험적 연구

  • Oh, Seung-Jin (Saenuri, Training Ship, Mokpo National Maritime University) ;
  • Jo, Dae-Hawn (Division of Marine Engineering, Mokpo National Maritime University)
  • 오승진 (목포해양대학교 실습선 새누리호) ;
  • 조대환 (목포해양대학교 기관공학부)
  • Received : 2014.12.31
  • Accepted : 2015.02.24
  • Published : 2015.02.28
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Abstract

Slamming means that the hull hits the waves and receives impact pressure. This slamming effect may cause harm to people and when you put the hull at risk. so it is very harmful for cargo safety. Therefor slamming impact pressure should be fully considered in ship designing. In this study the model of wedged type structure are produced aimed to simulate a free fall that the experiments were carried out on different weight and free fall height. The flow field has been obtained by 2-frame grey level cross correlation PIV(Particle Image Velocimetry) method and experiment was divided into water entry and water exit. The impact pressure of free fall structure by a pressure acquisition system apply to dewetron system. The angles between a model and the water surface are adapted $15^{\circ}$ respectively. The weight change of models was given as 1.5, 1.8 and 2.0kg. To study slamming phenomenon for free fall height the experiments were carried out by the free fall height of 100, 200 and 300mm. The experimental value of the impact pressure according to the changes in weight was increase impact pressure in proportion to the increase in weight and higher free falling height has also influenced the increase in impact pressures.

슬래밍은 선체가 파도와 부딪히며 선수, 선미에서 강한 충격압력을 받아 급격한 진동이 발생되는 현상이다. 이러한 슬래밍은 사람에게는 승선감의 불쾌감을 주고, 선체에는 구조적인 위험을 주며 화물의 안전과도 깊은 관계가 있다. 따라서 선박 설계기준에는 슬래밍에 의한 충격압력을 충분히 고려한 구조설계를 해야 한다. 본 연구에서는 자유낙하 하는 쐐기형 구조물의 중량 및 낙하높이의 변화에 따른 슬래밍 충격 압력 및 유동장의 유동특성을 알아보고자 실험을 수행하였다. 유동장의 계측은 2-프레임 그레이레벨 상호상관 PIV기법을 이용해 접수와 이수로 구분하여 실험하였으며, 충격압력의 계측은 압력계측장비인 Dewetron System을 이용하였다. 실험에서 모델과 자유수면간 이루는 각도는 $15^{\circ}$를 적용하였으며 이때, 중량의 변화는 1.5, 1.8 및 2.0kg이고 자유낙하높이는 100, 200 및 300mm로 하여 실험하였다. 실험값을 통한 중량의 변화에 따른 충격압력은 중량의 증가하는 것에 비례하여 충격압력 또한 증가했으며, 이러한 경향은 자유낙하 높이가 높을수록 영향을 많이 받았다.

Keywords

References

  1. Baker, G. S. and Keary, E. M.(1920). Experiments with Full-Sized Machines, British A.R.C. Reports and Memoranda No 683, pp. 1-10.
  2. Kang, Oh and Kwon(2009), An Experimental study on shallow water effect in slamming, Journal of the Society of Naval Architects of Korea , Vol. 23, No. 1, pp. 60-66.
  3. Lee and Cho(2009), "A study on PIV measurement of unsteady flow around disk caused by slide type valve quick closing", Journal of the Korean Society of Marine Environment & Safety Vol. 15, No. 3, pp. 251-256.
  4. Lee, Rim, Kim, Heo and Kim(2007), "A study on measurement of flare slamming of large container vessel (II) Characteristic analysis of measured slamming pressure", Journal of the Society of Naval Archetects of Korea, Vol. 44, No. 3, pp. 279-284. https://doi.org/10.3744/SNAK.2007.44.3.279
  5. Lee J. and Philip A. W.(2010), Experimental study of the hydro-impact of slamming in a modern racing sailboat, Journal of Sailboat Technology, article 2010-01, pp. 1-29.
  6. Manganelli, P. Wagemakers B. and Wilson P.(2003), Investigation of slamming loads using slam patches on a scaled model of an Open 60' class yacht, International Journal of Small Craft Technology, 145, pp. 47-62.
  7. Park, Oh, Kwon and Chung(2009), A study on slamming impact pressure, Journal of the Society of Naval Architects of Korea Vol. 23, No. 1, pp. 67-73.
  8. Park, Lee and Rim(2000), Whipping analysis of hull girders considering slamming impact loads, Journal of the Society of Naval Architects of Korea Vol. 37, No. 3, pp. 99-109.
  9. Von Karman T.(1929), The Impact of Seaplane Floats during Landing, N.A.C.A. TN321 Washington, pp. 1-8.
  10. Yum and Yoon(2008), "Numerical simulation of slamming phenomena for 2-D wedges, Journal of the Society of Naval Architects of Korea", Vol. 45, No. 5, pp. 477-484. https://doi.org/10.3744/SNAK.2008.45.5.477