The Effects Of Distortion Ratios On Tidal Currents,Waves And Sediment Models

In this paper, the effects of distorted ratios on physical models of tidal currents, waves and sediment transport have been studied by a series of generalized physical models and numerical models. The main contents are as follows:(1) The research situation of physical models for estuary and the effects of distortion ratios on physical models are reviewed. The theories and the methods for distortion ratio research are commented.(2) The basic equations of tidal currents, waves, sediment transport and the similarity theory of total sediment transport modeling for estuarine and coastal regions are given.(3) According to the conditions of North Passage in Yangtze Estuary, five generalized physical models, with distortion ratios 2.5, 4, 6, 8.33, 12.8, are designed. The horizontal scales are 200, 400, 660, 1000, 1600 and vertical scales are 80, 100, 110, 120, 125 respectively.(4) The tidal levels, velocities, wave heights and sediment concentrations in five models are verified. The similarity is satified for each model in tidal currents, waves and sedimentation respectively.(5) The experiments of sediment transport under the actions of tidal currents and waves are carried out. The effects of distortion ratios on the tidal currents, the depths of scour and deposit and the discharge of bed loads in the channel are discussed.(6) The experiments of sediment transport under the conditions of a pair of groins and slant groins and two pair of groins are carried out. The effects of distortion ratios on the tidal currents, the depths of scour and deposit in the channel and the local scour in the groin heads are discussed.(7) The relationship of local scour depth between distortion models and the normal model is obtained.(8) The effects of distortion ratios on distribution of velocities and sediment concentrations in the vertical direction are analyzed. The numerical models of tidal currents and sediment transport for three generalized physical models are established. From the numerical models, the effects of distortion ratios on tidal currents and sediment scour and silt in the channel are given.