다방향 쇄파의 에너지 소산 및 전이 특성에 관한 연구

Abstract

Wave energy dissipation and energy transfer between wave components during the directional wave breakings are investigated experimentally. Directional incipient and plunging breakers were generated by focusing the multi-frequency and multi-directional wave components at a designed location based on constant wave amplitude and constant wave steepness frequency spectrum. The time series of surface wave elevation were measured at 9 different locations around the wave focusing point using a wave gauge array and the horizontal velocity of fluid motion was also measured to examine the variation of directional spreading function. By comparing energy spectrums before and after the breaking, the characteristics of energy dissipation and energy transfer caused by wave breaking are investigated and their dependences on directionality as well as frequency are analyzed. The breakings significantly dissipate wave energy in the upper region of peak-frequency band while enhance wave energy in the low-frequency band by energy transfer.