Mathematical model of wave diffraction for partially reflecting breakwaters

Abstract

This study derived analytical solutions for wave diffraction by a semi-infinite breakwater or collinear, symmetrical, and asymmetrical double breakwaters with partial reflection. The diagrams of the diffraction coefficient distribution for double breakwaters are presented. The analytical results of this study are compared to those of other analytical diffraction solutions in detail, and the effects of the reflection coefficient and layout of the breakwaters on the wave heights are analyzed. The results reveal that the reflection coefficient of the breakwaters mainly affects the wave heights in the reflection area in front of the breakwaters, and somewhat affects the wave heights in the shielding area behind the breakwaters. The reflection coefficients’ effect on the shielding area is closely related to the breakwater layout. In addition, the layouts of asymmetrically diverging double breakwaters are closely related to their shielding effects. The main factors that affect the wave heights in the shielding area are the inclination angles of breakwaters, the ratio of gap width to wavelength and the position of right breakwater head. The impact of those factors is not independent, but interrelated; the above factors, rather than just one of them, should be considered comprehensively when the breakwater layout is designed.