• Title/Summary/Keyword: Long wave

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A Study on Operation Rate and Output of Wave Power Generator by Waves Condition (파랑 조건에 따른 파력발전장치의 가동률과 발전량 산정에 대한 연구)

  • Ryu, Hwang-Jin;Hong, Key-Yong;Shin, Seung-Ho;Kim, Sang-Ho
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.615-619
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    • 2009
  • This paper is investigated to variation of wave power generation operation rate, operating capacity and output with the wave conditions represented by wave height-period window. By the use of the long-term wave data from 1979 to 2002 which is provided by Korea Ocean Research & Development Institute(KORDI), we calculated the monthly variation of significant wave height(Hs), zero-up crossing period(Tz) and distribution of wave appearance rate. And using the same wave data, it was charted the Hs-Tz and wave-energy scatter diagrams.

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Investigation of Characteristics of Waves Generated in Two-Dimensional Wave Channel (2차원 조파수조에서의 파 생성 특성 조사)

  • Ahn, Jae-Youl;Choi, Jung-Kyu;Kim, Hyoung-Tae
    • Journal of Ocean Engineering and Technology
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    • v.27 no.4
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    • pp.68-75
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    • 2013
  • This paper investigates the characteristics of waves generated by a flap-type wave maker in a two-dimensional wave channel. Measurements are carried out for various water depths, wave heights, periods, and lengths capacitance-type wave height gages. The experimental results are shown to satisfy the dispersion relation of the linear wave theory. For waves with a small height and long period, the wave profiles agree well with those of the linear wave theory. However, as the wave height and period become higher and shorter, respectively, it is shown that the wave profiles measured in the present experiments are different from the linear wave profiles, and the measured wave heights are smaller than the target wave heights, which may be due to the non-linearity of the waves. As the wave progresses toward the channel end, the wave height gradually decreases. This reduction in the wave height along the wave channel is explained by the wave energy dissipation due to the friction of the side walls of the channel. The performance of the wave absorber in the channel is found to be acceptable from the results of the wave reflection tests.

Characteristics of Spread Parameter of the Extreme Wave Height Distribution around Korean Marginal Seas (한국 연안 극치 파고 분포의 확산모수 특성)

  • Jeong, Shin-Taek;Kim, Jeong-Dae;Ko, Dong-Hui;Kim, Tae-Heon
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.21 no.6
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    • pp.480-494
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    • 2009
  • Long term extreme wave data are essential for planning and designing coastal structures. Since the availability of the field data for the waters around Korean peninsula is limited to provide a reliable wave statistics, the wave climate information has been generated by means of long-term wave hindcasting using available meteorological data. KORDI(2005) has proposed extreme wave data at 106 stations off the Korean coast from 1979 to 2003. In this paper, extreme data sets of wave(KORDI, 2005) have been analyzed for best-fitting distribution functions, for which the spread parameter proposed by Goda(2004) is evaluated. The calculated values of the spread parameter are in good agreement with the values based on method of moment for parameter estimation. However, the spread parameter of extreme wave data has a representative value ranging from about 1.0 to 2.8 which is larger than some foreign coastal waters, it is necessary to review deep water design wave.

Heat Transfer of an Evaporating Liquid on a Horizontal Plate

  • Joo, Sang-Woo;Park, Min-Soo;Kim, Min-Suk
    • Journal of Mechanical Science and Technology
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    • v.19 no.8
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    • pp.1649-1661
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    • 2005
  • We consider. a horizontal static liquid layer on a planar solid boundary. The layer is evaporating when the plate is heated. Vapor recoil and thermo-capillary are discussed along with the effect of mass loss and vapor convection due to evaporating liquid and non-equilibrium thermodynamic effects. These coupled systems of equations are reduced to a single evolution equation for the local thickness of the liquid layer by using a long-wave asymptotics. The partial differential equation is solved numerically.

Analysis on the Characteristics of the group-bounded long wave (파군에 따른 장주기파의 거동특성 해석)

  • 이철응;이길성;편종근
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1993.07a
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    • pp.130-136
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    • 1993
  • 단주기파군에 의하여 발생되는 장주기파를 나타내는 용어로 surf-beats, edge파 그리고 평균수위강하(set-down 또는 group bounded long wave)등이 사용되어지고 있다. 이들의 발생성격에 대한 물리적 특성으로, surf-beats와 edge파는 일반적으로 천해역에서 발생하는 비선형간섭(쇄파특성) 및 해안선의 반사성과 관련있으며 평균수위강하는 단지 단주기파에 의하여 형성된 파군의 특성과 관련을 갖게 된다. (중략)

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The Comparison of the Bead Size Effect on the Two Wave Patterns Induced in One Reaction System

  • Heo, Do Seong;Kim, Min Seok;Jo, Sang Jun
    • Bulletin of the Korean Chemical Society
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    • v.22 no.8
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    • pp.867-871
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    • 2001
  • We have studied the characteristic wave propagation in 1,4-CHD-Bromate-Ferroin reaction system and we have examined the bead size effect on the wave propagation of the system by adopting a half-divided Petri dish which is separated into two parts by the size of cation-exchange resin. It has been done to understand the reaction process inducing the characteristic wave behavior in the system. The characteristic wave behavior of the system is in the spontaneous induction of a revival wave with a long time lag. We have obtained a result that the revival wave is not affected by the size of catalyst-doped beads while the initially induced wave is influenced by the size of beads. It means that the two waves are induced by different reaction processes each other and the revival wave is induced by an uncatalyzed reaction process.

Wave power extraction by multiple wave energy converters arrayed in a water channel resonator

  • Kim, Jeongrok;Cho, Il-Hyoung
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.13 no.1
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    • pp.178-186
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    • 2021
  • The wave power extraction by multiple Wave Energy Converters (WECs) deployed in a Y-shaped Water Channel Resonator (WCR) has been investigated. A WCR consists of a long water channel, and a V-shaped wave guider installed at the entrance of a water channel. If the period of the incident waves coincides with the natural periods of the fluid in a WCR, resonance occurs, as a result, the internal fluid in a WCR is greatly amplified. To estimate the wave power by multiple WECs placed at the antinodal points in a WCR, the heave motion response, time-averaged power, and capture width ratio were calculated for several design parameters. Also, the systematic model tests were conducted in a 2D wave tank. The numerical results are in good agreement with the experimental data. It was verified that a WCR helps the WECs to produce electricity more effectively by amplifying the wave energy in a WCR.

Smart passive control of buildings with higher redundancy and robustness using base-isolation and inter-connection

  • Murase, Mitsuru;Tsuji, Masaaki;Takewaki, Izuru
    • Earthquakes and Structures
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    • v.4 no.6
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    • pp.649-670
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    • 2013
  • It is known that a base-isolated building exhibits a large response to a long-duration, long-period wave and an inter-connected system without base-isolation shows a large response to a pulse-type wave. To compensate for each deficiency, a new hybrid passive control system is investigated in which a base-isolated building is connected to another building (free wall) with oil dampers. It is demonstrated that the present hybrid passive control system is effective both for pulse-type ground motions and long-duration and long-period ground motions and has high redundancy and robustness for a broad range of disturbances.

Generation of Long Water Waves by Moving Submerged Bodies (수중물체의 운동에 의한 장수파의 생성)

  • Seung-Joon,Lee
    • Bulletin of the Society of Naval Architects of Korea
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    • v.24 no.2
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    • pp.55-61
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    • 1987
  • The wave system due to a moving submerged body is investigated both theoretically and numerically. Boussinesq equation, which is derived under the assumption that the effects of nonlinearity and wave dispersion are of the same order, is generalized to take the forcing agency into account. Furthermore, under the more restrive assumption that the disturbance is of higher order, inhomogeneous Korteweg-de Vries equation is derived. These equations are solved numerically to obtain the generated wave system and the wave-making resistance. These results are compared with those given by the linear theory.

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