• Title/Summary/Keyword: Wave board stroke

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Linear Analysis of Water Surface Waves Generated by Submerged Wave Board Whose Upper and Lower Ends Oscillate Horizontally Freely (상하단이 자유롭게 수평동요하는 수중 조파판에 의해 생성된 수면파의 근사해석)

  • Kim, Hyochul;Oh, Jungkeun;Kwon, Jongoh;Lew, Jae-Moon
    • Journal of the Society of Naval Architects of Korea
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    • v.56 no.5
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    • pp.418-426
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    • 2019
  • To derive a simplified analytic solution which can be utilized as a fundamental solution for the wave maker design, a segment of the wave board has been idealized as a submerged line segment in a two dimensional domain of a wave flume. The lower end of the line segment could be located at arbitrary depth of the wave flume and the upper end of the board could be also submerged to any depth from the free surface. The freely oscillating motion of the wave board is assumed to be defined by determining the condition of horizontal oscillation on both ends differently. The submerged wave board oscillating in horizontal direction could be specified by selecting the amplitude, frequency and the phase lag differently on lower and upper ends of the board. The simplified two dimensional wave generated by the wave board segment has been obtained by the first order perturbation method. It is found that the general solution of the freely oscillating wave board in two dimensional domain could be decomposed into the solution of flap motion with lower end hinge and swing motion with upper end hinge. The case study of the analytic solutions has been carried out to evaluate the effect on the wave height due to the difference of oscillation frequency, phase difference and variation of stroke between for the motion of both ends. It is found that the solution of the freely oscillating wave board could be utilized for the development of high performance wavemaker especially for irregular waves.

A Parametric Study of the Wave-Generation Performance of a Piston-Type Wave Maker (피스톤 타입 조파기의 형상 매개변수에 대한 조파성능 연구)

  • Kwon, Do-Soo;Kim, Sung-Jae;Koo, Weoncheol
    • Journal of Ocean Engineering and Technology
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    • v.33 no.6
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    • pp.504-509
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    • 2019
  • The wave-generation performance of a piston-type wave maker was analyzed using the numerical wave tank technique, and the numerical results were compared with theoretical solutions. A two-dimensional frequency domain analysis was conducted based on the Rankine panel method. Various parameters were used to examine the wave-generation performance, such as the width and gap of the wave board. The effects of the thickness of the wave board and of the gap from the bottom of the tank were evaluated. The difference in the amplitude of the generated wave between the analytical solution and the numerical result was examined, and its causes were addressed due to the gap flow between the bottom of the tank and the wave board. This parametric analysis can be utilized to design an optimum wave make parametric analysis to design an optimum wave maker that can generate waves with amplitudes that can be predicted accurately.