Design of Y‐Frame Floating Breakwater

Existing floating breakwaters of different types are examined and the performance of each studied. An important parameter identified with the performance characteristics of floating breakwaters is the width to wave length ratio $(W/L)\text{.}$ Earlier studies revealed that to achieve a transmission coefficient $\left(K_t\right)$ less than 0.5, $W/L$ ratio should invariably be greater than 0.3 for any type of floating breakwater. Hydraulic model tests reported herein suggest that fixing a row of pipes with certain length and interval at the bottom of a trapezoidal float reduces $W/L$ ratio to around 0.15 to achieve a transmission coefficient less than 0.5. This essentially brings down the width requirement of the floating breakwater by half, reducing the cost. Nondimensional graphs indicating the variation of transmission and reflection coefficients with respect to relative depth $(d/h)$ relative width $(W/L)\text{,}$ wave parameter $(H_i/g{T}^2)\text{,}$ and gap to diameter ratio $(b/D)$ are presented in this paper. The experimental results for $K_t$ are compared with the results already reported by past investigators on similar studies.