Influence Pattern Of Navigation Channel And Breakwater Gap Upon Wave Propagation

Wave diffractions and refractions occur when the waves meet structures and variational landform, which has remarkable influence on wave propagation. Especially when the waves go through deep navigation channel with different incident angles, the diffractions and refractions are serious and will probably improve the wave factors of the structures. To the questions of engineering, numerical simulation and experiment are used to investigate the pattern of influence of breakwater gap and navigation channels upon wave propagation.1) The result of experiment on Da yaowan engineering indicates that the navigation channelhas great effect on wave propagation. In this experiment, the change of wave height up to 20 to 30 percent in 5 to 6 wave length.2) A wave numerical model is developed, based on the typical Boussinesq equation, andexamed through the simulation of diffraction only compared with physical experiment. The wave distribution in harbor is calculated with and without navigation channels. The compared results show that wave transmutation is greatly effected by the navigation channels and can't replace by diffraction condition only. For example, in the condition of relative water depth of channel h/d=1.2, wave height in navigation channel is 16 percent3) The simulation is carried out in order to study the relative wave height in differentconditions. These factors include the width of breakwater gap, wave incident angle and angle distribution, the water depth of channel, the channel width and slope, etc. The results show that the different factors have different influence, in which wave incident angle has a significant effect and channel slope has little.·As far as the wave incident angle( θ), it has notable influence when θ is in the range of 10 degree and 20 degree.·As far as the relative water depth of channel(h/d), its influence can be ignored when the extent of wave propagation less than 4 wave length, while the extent larger than 4 wave length, it has notable influence and can not be ignored.4) It researches the effect of channel different scale and wave incident angle on the structurenear the channel. The effect of channel scale on the wave parameter in breakwater design has a similar rule with the research in harbor. But in contract to wave incident angel, when wave propagate in little angle, the wave height in head-on side of the channel in front of the breakwater is much larger than the wave height in back-side,.5) Da yaowan engineering is modeled by numerical method. And the results of the researchprovide reference for the planning and designing of port and navigation channel works.