The Study Of Wave-dissipating Performance Of Twin-plate Penetrating Breakwater

In allusion to a concept of penetrating breakwater—twin-plate breakwater, wave interaction with this type of breakwater and its effectivity in wave-dissipating performance are studied in this dissertation through physical model tests and numerical simulation.Based on a series of physical model tests of regular and irregular waves, wave-dissipating effects of twin-plate breakwater are studied. Four main factors which influence wave- dissipating performances of twin-plate breakwater are took into account including relative plate width (B/L), relative spacing(s/d). relative water depth (d/L) and wave steepness (H/L).A numerical flume with absorbing layer and zero reflection is set up using boundary element method. Wave-dissipating performances of the twin-plate breakwater model and its hydrodynamic characteristics are studied for different incident waves through numerical calculations.From integrating physical model tests with numerical calculations, results are as follows: Relative plate width (B/L), relative spacing(s/d), relative water depth (d/L) and wave steepness (H/L) etc have some influence on wave-dissipating performance of the breakwater. Twin-plate breakwater is certainly effective in wave-dissipating performance according to the transmission coefficient less than 0.5(for irregular waves):For effluent dike:· relative spacing s/d =0.36, relative water depth (d/L)= 0.21 ～0.33, wave steepness (H/L) =0.02～0.06, relative plate width (B/L)>0.31;For surface dike:· relative spacing s/d=0.25, relative water depth (d/L)=0.32～0.39, wave steepness (H/L)=0.03～0.05, relative plate width (B/L) >0.40;· relative spacing s/d=0.30, relative water depth (d/L)=0.24～0.39, wave steepness (H/L)=0.02～0.05, relative plate width (B/L) >0.30;· relative spacing s/d is 0.38, relative water depth (d/L)=0.21～0.33, wave steepness(H/L)=0.03～0.05, relative plate width (B/L) >0.40. Based on the theory of wave interaction with twin-plate breakwater, time-domain calculation model of nonlinear wave interaction with breakwater is put forward by boundary element method. Wave-dissipating performances of twin-plate breakwater and its hydrodynamic characteristics are analyzed through concrete examples for different incident waves.