• Title, Summary, Keyword: Korean Wave

Search Result 13,763, Processing Time 0.07 seconds

An Experimental Study on Wave Focusing Efficiency in the Generation of Directional Extreme Waves (파랑집중에 의한 다방향 극한파 생성의 효율성에 관한 실험적 연구)

  • 홍기용;류슈쉐;양찬규
    • Journal of Ocean Engineering and Technology
    • /
    • v.16 no.5
    • /
    • pp.1-6
    • /
    • 2002
  • Extreme waves are generated in a model basin based on directional wave focusing. The targeted wave field is described by double summation method and it is applied to serpent-type wavemaker system. The extreme crest amplitude at a designed location is obtained by syncronizing the phases and focusing the directions of wave components. Two distinguished spectrums of constant wave amplitude and constant wave steepness are adapted to describe the frequency distribution of component waves. The surface profile of generated wave packets is measured by wave guage array and the effects of dominant spectral parameters governing extreme wave characteristics are investigated. It is found that frequency bandwidth, center frequency, shape of frequency spectrum and directional range play a significant role in the wave focusing. In particular, the directional effect significantly enhances the wave focusing efficiency.

Research on Wave Kinematics & Wave Loads in Breaking Wave (쇄파의 유동구조 및 쇄파력에 대한 연구)

  • LEE BYEONG-SEONG;JO HYO-JAE;GOO JA-SAM;KANG BYUNG-YOON
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
    • /
    • /
    • pp.96-101
    • /
    • 2004
  • When the wind blows hard, most waves are breaking in sea. Breaking waves occur, exceeding limitation of wave steepness(wave height/wave length=l/7). Because a wave of single angular frequency couldn't generate the breaking phenomena at two dimensional ocean engineering basin, the breaking wave can be generated by the superposition of waves with various angular frequencies. We research how are the particle kinematics in the breaking wave and the magnitude of the breaking wave exciting force. We compare the force in a regular wave which has same specifications(wave height, period and length) as the breaking wave. Also the experimental results of wave exciting force and particle velocity are investigated by comparison on the analytic results using the potential theory.

  • PDF

Research on Wave Kinematics and Wave Loads in Breaking Wave (쇄파의 유동구조 및 쇄파력에 관한 연구)

  • Lee, Soo-Lyong;Kang, Byung-Yoon;Lee, Byeong-Seong
    • Journal of Ocean Engineering and Technology
    • /
    • v.21 no.1
    • /
    • pp.18-24
    • /
    • 2007
  • When the wind blows strong, most waves are breaking at sea. Breaking waves occur by exceeding the limitation of wave steepness (wave height/wave length = 1/7). Because a wave of single angular frequency couldn't generate the breaking phenomena at a two-dimensional ocean engineering basin, the breaking wave can be generated by the superposition of waves with various angular frequencies based on dispersion relation. This study investigates the particle kinematics in the breaking wave and the magnitude of the breaking wave exciting force at the breaking point and breaking region. We compare the regular wave load in a regular wave, which has same specifications (wave height, period and length), with the breaking waveload. Also, the experimental results of wave exciting force and particle velocity are investigated, by comparison with the analytic results using the potential theory.

Effect of Anisotropic Ratio for Rayleigh Wave of a Half-Infinite Composite Material (반 무한 복합체의 Rayleigh 표면파에 대한 이방성비의 영향)

  • Baek, Un-Cheol;Hwang, Jae-Seok;Song, Yong-Tae
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.25 no.3
    • /
    • pp.502-509
    • /
    • 2001
  • In this paper, when stress waves are propagated along the reinforced direction of the composite, the characteristic equation of Rayleigh wave is derived. The relationships between velocities of stress waves and Rayleigh wave are studied for anisotropic ratios(E(sub)11/E(sub)12 or E(sub)22/E(sub)11). The increments of anisotropic ratios is made by using known material properties and being constant of basic properties. When the anisotropic ratios are increased, Rayleigh wave velocities to the shear wave velocities are almost equal to 1 with any anisotropic ratios. Rayleigh wave velocities to the longitudinal wave velocities and Shear wave velocities ratio to the longitudinal wave velocities are almost identical each other, they are between 0.12 and 0.21. When the anisotropic ration is very high, that is, E(sub)11/E(sub)22=46.88, Rayleigh wave velocities and the shear wave velocities are almost constant with Poissons ratio, longitudinal wave velocities are very slowly increased with the increments of Poissons ratios. When E(sub)11(elastic modulus of the reinforced direction)and ν(sub)12 are constant, Rayleigh wave velocities and the shear wave velocities are steeply decreased with the increments of anisotropic ratios and the velocities of longitudinal wave are almost constant with them. When E(sub)22(elastic modulus of the normal direction to the fiber) and ν(sub)12 are constant, Rayeigh wave velocities is slowly increased with the increments of anisotropic ratios, the shear wave velocities are almost constant with them, the longitudinal wave velocities are steeply increased with them.

Study on the wave resonance-stimultion and receptionfor the BIO-KI (생체 기에 대한 피동공명적인 연구)

  • Ryu Gyeong Ho;Kim Gyeong Cheol;Lee Yong Tae
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.17 no.2
    • /
    • pp.263-274
    • /
    • 2003
  • The present condition of study on the wave-resonance for the bio-KI is observed. And the probroms of reception attendent on the stimulation of wave is observed centering around the sensory organ. The results is as follows: In the wave-resonant stand point, the tendency of studying on KI is showed in the several field all over the world. Because it is originated radionics, the wave-resonant tools of MRA insistenting minute-magnetism-resonance-apparatus need the more severe data in the side of electric circuit. The wave resonance apparatus according to the frequency occurance transmits low-frequency's vibration ratio to the electric stimulating aspect. The wave-water is considered on the application of wave-resonance transcription on the water, and needs the comprehension of torsion-field level. The wave-stimulation of the bio-KI and the reception of the sensory-organ is observed the connection of the sensory-organ and it's corresponding wave. The informations recorded in the wave are distinguished patternly. And the several shaping waves transmit the informations each other through the resonnance. The wave theory is explained the LEE(理) as the wave-pattern and the KI(氣) as the revelation of the patterned-wave in the LEE-KI theory(理氣論), moreover the SHIN(神) as the information of the wave-pattern and the KI as the energy of the wave and the JEUNG(精) as the material of the wave in the JEUNG-KI-SHIN theory(精氣神論). In this point, the study on the wave-resonance of bio-KI is thought that it is significantly in the study method for oriental medicine. The sum of the wave makes the moving body and forms the universe. It means that the several wave patterns gather and form new field. The pattern is a kind of the information and the information is not materially. The information of wave-pattern is the arrangement and the combination of the material source.

Study on Freak Wave Characteristics and Approximation of Wave Spectrum in Uljin Sea Area (울진해역의 Freak wave 특성과 스펙트럼 근사에 대한 연구)

  • Ryu, Hwang-Jin;Hong, Sa-Young
    • Journal of Ocean Engineering and Technology
    • /
    • v.26 no.2
    • /
    • pp.8-13
    • /
    • 2012
  • This paper investigates the statistical properties of waves in the sea area of Uljin, which is located in the East Sea area of Korea. The wave data were measured using AWAC (Acoustic Wave and Current Meter), which was installed at a 16-m water depth from November 2010 to March 2011. The wave data acquisition rate, Hmax, monthly mean Hs, Tz, Tp, and wave direction are summarized. The distributions of Hs and Tz were analyzed using the Hs-Tz scatter diagrams. The measurement wave data were analyzed to investigate freak wave characteristics. By comparing the wave spectrum using the measurement wave data with the wave spectrum obtained by varying the JONSWAP wave spectrum, it was possible to approximate the wave spectrum shape at the Uljin Sea area.

Effects of interfacial shear stress on laminar-wavy film flow (층류-파동 액막 유동에 대한 계면 전단응력의 영향)

  • Kim, Byeong-Ju;Jeong, Eun-Su;Kim, Jeong-Heon
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.22 no.7
    • /
    • pp.992-1000
    • /
    • 1998
  • In the present study the behavior of laminar-wavy film flowing down a vertical plate was studied analytically. The effects of film Reynolds number and interfacial shear stress on the mean film thickness, wave amplitude, wave length, and wave celerity were analysed. The anayltical results on the periodic-wave falling film showed good agreements with experimental data for Re < 100. As the film Reynolds number increased, mean film thickness, wave amplitude, and wave celerity increased, but wave length decreased. Depending on the direction of interfacial shear stress, the shape of wavy interface was disturbed significantly, especially for the intermediate-wave. As the interfacial shear stress increased, for the periodic-wave film, wave amplitude and wave celerity increased, but mean film thickness and wave length decreased.

On the Statistical Characteristics of the New Year Wave (New Year Wave의 통계적 특성에 대하여)

  • Kim, Do Young
    • Journal of Ocean Engineering and Technology
    • /
    • v.27 no.1
    • /
    • pp.102-108
    • /
    • 2013
  • In this paper time series wave data, which were measured at the Draupner platform in the North Sea on 1995, are used to investigate statistical characteristics of nonlinear wave. Various statistical properties based on time and frequency domain are examined. The Gram-Chalier distribution fits the probability of wave elevation better than the Gaussian distribution. The skewness of wave profile is 0.393 and the kurtosis is 4.037 when the freak wave is occurred. The nonlinearity of D1520 data is higher than two adjacent wave data. AI index of the New Year Wave is 2.11 and the wave height is 25.6m. The zero crossing wave period of the New Year Wave is 12.5s which is compared to the average zero up-crossing period 11.3s. The significant steepness of wave data is 0.077 when the freak wave was occurred. H1/3/${\eta}_s$ does not increases as the kurtosis increases and the values is close to 4. The New Year Wave belongs to highly nonlinear wave data packet but the AI index is within linear focusing range.

A Practical Application of Multiple Wave Models to the Small Fishery Harbor Entrance

  • Jung, Jae-Hyun;Lee, Joong-Woo;Jeon, Min-Su;Kang, Seok-Jin
    • Journal of Navigation and Port Research
    • /
    • v.31 no.7
    • /
    • pp.579-587
    • /
    • 2007
  • Samchunpo(Sin Hyang) Harbor is located in the bay of Sa Chun, the central south coast of Korean peninsula. The harbor and coastal boundaries have been protecting by natural coastal islands and shoals. Currently, The Sin Hyang harbor needs maintenance and renovation of the sheltered structures against the weather deterioration and typhoon damages. Consequently to support this, the calculation of accurate design wave through the typhoon wave attack is necessary. In this study, calculation of incident wave condition is simulated using steady state spectrum energy wave model(wide area wave model) from 50 years return wave condition. And this simulation results in wide offshore area were used for the input of the extended mild slope wave model at the narrow coastal area. Finally, the calculation of design wave at Sin Hyang harbor entrance was induced by Boussinesq wave model(detail area wave model) simulation. The numerical model system was able to simulate wave transformations from generation scale to shoreline or harbor impact. We hope these results will be helpful to the engineers doing placement, design, orientation, and evaluation of a wide range of potential solutions in this area.

Comparison of Edge Wave Normal Modes (Edge Wave 고유파형의 비교)

  • Seo, Seung Nam
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.25 no.5
    • /
    • pp.285-290
    • /
    • 2013
  • Both full linear and shallow water edge waves are compared to get a better understanding of edge wave behavior. By using method of separation of variables, we are able to get solution of full linear edge wave presented by Ursell (1952) without derivation. The shallow water edge waves show dispersive features despite being derived from shallow water equations. When bottom slope is mild enough, shallow water edge wave tends to linear edge wave and has some advantages of manipulation. Solution of edge wave generated by a moving landslide of Gaussian shape is constructed by an expansion of shallow water normal modes. Numerical results are presented and discussed on their main features.