Author(s): S. Onodera; K. Miyaoka; M. Taniguchi; M. Saito; T. Ishitobi; J. Chen; G. Liu; Y. Fukushima
Linked Author(s): Jianquan Chen, Guangyu Liu
Keywords: Seawater exchange breakwater; Resonance; Hydrodynamic prediction; Hydraulic experiment; Regular and irregular waves
Abstract: The resonance period of an L-shaped channel in a caisson was analytically predicted for the seawater exchange breakwater of Lee et al. (1999). Hydraulic experiments were conducted for a composite breakwater with a rear reservoir, which was one of the seawater exchange breakwaters developed by Lee et al. For regular waves, the water surface elevation in the channel and the flow rate through the breakwater were measured. For irregular waves, the flow rate through the breakwater and the reflection coefficient on the breakwater were measured. The resonant maximum values for both the surface elevation, and the flow rate and the resonant minimum values in the reflection coefficient, were all at wave periods slightly longer than those predicted analytically. The measured resonance period for irregular waves was closer to the predicted value than that for regular waves. If the resonance period of the L- shaped channel was fitted to the dominant period of incident waves, there would be high efficiency of seawater exchange between the inside and outside of the harbor.
Year: 2005