Sediment transport capacity is a fundamental parameter in sediment transport theory and its accurate calculation is important from both theoretical and engineering viewpoints. The capacity of sediment transport has be...Sediment transport capacity is a fundamental parameter in sediment transport theory and its accurate calculation is important from both theoretical and engineering viewpoints. The capacity of sediment transport has been studied extensively by many researchers in the last decades. Nevertheless, the underlying mechanism behind sediment transport capacity in estuaries remains poorly understood. The current study aims to explore the impact of the river–tide interaction on sediment transport and establish a formula of sediment transport capacity under the river–tide interaction. The impact of the river–tide interaction on the hydrodynamics and sediment dynamics in the Changjiang Estuary was analyzed, a practical method for describing the variation in tide-runoff ratio was established,and a formula of sediment transport capacity considering the impact of river–tide interaction was proposed by introducing the tide-runoff ratio. The new method bridged the gap between two well-known sediment transport capacity methods by considering the variation in the index a for the gravitational term and overcomes the drawback of distinguishing flood/dry season or spring/ebb tide in the calculation of estuarine sediment transport. A large amount of flow and sediment data obtained from the Changjiang Estuary were collected to verify the proposed formula. The effect of salt-fresh water mixture and the morphological evolution on sediment transport capacity of the Changjiang Estuary were discussed.展开更多
The erosion process of a cohesive sediment after consolidation was studied experimentally in a closed conduit system. The test samples investigated in this study are mixtures of sand and clay with variable composition...The erosion process of a cohesive sediment after consolidation was studied experimentally in a closed conduit system. The test samples investigated in this study are mixtures of sand and clay with variable compositions and different consolidation times. The main concern of this study is the effects of the dry density of the consolidated sediment on scour rate. A scour rate formula is derived and further interpreted based on the experimental results.展开更多
The near field stahility and mixing characteristics of buoyant jets produced by thermal diffuse in quiescent shallow water are inw.stigated numerically to predict under what combinations of discharge and ambient chara...The near field stahility and mixing characteristics of buoyant jets produced by thermal diffuse in quiescent shallow water are inw.stigated numerically to predict under what combinations of discharge and ambient characteristics the near field will be stable or unstable, Analyses for different discharging types show that the discharge stability is purely dependent on the near-field hehavior of the jets, or the dynam ic interaction of the buoyant jet region, the surface impinge ment region and the internal hydraulic jump region, and is independent of the far-field geometry of the receiving water. The stability criterion is a function of the relative submerged depth, and source densimetrie Froude number.展开更多
A set of new 2-D equations of interchange between suspended sediment and bed materials was serived by theoretical deduction based on the systematic summarization and assessment the previous studies of simulating the i...A set of new 2-D equations of interchange between suspended sediment and bed materials was serived by theoretical deduction based on the systematic summarization and assessment the previous studies of simulating the interchange between suspended sediment and bed materials in the Lower Yellow River. This model was used to simulate the erosion and deposition processes caused by the interchange between suspended sediment and bed materials in a sketch channel. The results show that these equations are well consistent with the laws of interchange between suspended sediment and bed materials. Furthermore, compared with previous models, it has important practical value not only because of strong theoretical foundation, but also for smaller amount of calculating work and convenient application in practice.展开更多
基金financially supported by the Program of the National Key Research and Development Plan(Grant No.2017YFC0405501)the National Natural Science Foundation of China(Grant Nos.51725902 and 51579186)
文摘Sediment transport capacity is a fundamental parameter in sediment transport theory and its accurate calculation is important from both theoretical and engineering viewpoints. The capacity of sediment transport has been studied extensively by many researchers in the last decades. Nevertheless, the underlying mechanism behind sediment transport capacity in estuaries remains poorly understood. The current study aims to explore the impact of the river–tide interaction on sediment transport and establish a formula of sediment transport capacity under the river–tide interaction. The impact of the river–tide interaction on the hydrodynamics and sediment dynamics in the Changjiang Estuary was analyzed, a practical method for describing the variation in tide-runoff ratio was established,and a formula of sediment transport capacity considering the impact of river–tide interaction was proposed by introducing the tide-runoff ratio. The new method bridged the gap between two well-known sediment transport capacity methods by considering the variation in the index a for the gravitational term and overcomes the drawback of distinguishing flood/dry season or spring/ebb tide in the calculation of estuarine sediment transport. A large amount of flow and sediment data obtained from the Changjiang Estuary were collected to verify the proposed formula. The effect of salt-fresh water mixture and the morphological evolution on sediment transport capacity of the Changjiang Estuary were discussed.
基金supported by the National Natural Science Foundation of China (Grant No.50679064)
文摘The erosion process of a cohesive sediment after consolidation was studied experimentally in a closed conduit system. The test samples investigated in this study are mixtures of sand and clay with variable compositions and different consolidation times. The main concern of this study is the effects of the dry density of the consolidated sediment on scour rate. A scour rate formula is derived and further interpreted based on the experimental results.
文摘The near field stahility and mixing characteristics of buoyant jets produced by thermal diffuse in quiescent shallow water are inw.stigated numerically to predict under what combinations of discharge and ambient characteristics the near field will be stable or unstable, Analyses for different discharging types show that the discharge stability is purely dependent on the near-field hehavior of the jets, or the dynam ic interaction of the buoyant jet region, the surface impinge ment region and the internal hydraulic jump region, and is independent of the far-field geometry of the receiving water. The stability criterion is a function of the relative submerged depth, and source densimetrie Froude number.
基金the National Natural Science Foundation of Chinathe Yellow River Conservancy Commission (Grant No. 50339020).
文摘A set of new 2-D equations of interchange between suspended sediment and bed materials was serived by theoretical deduction based on the systematic summarization and assessment the previous studies of simulating the interchange between suspended sediment and bed materials in the Lower Yellow River. This model was used to simulate the erosion and deposition processes caused by the interchange between suspended sediment and bed materials in a sketch channel. The results show that these equations are well consistent with the laws of interchange between suspended sediment and bed materials. Furthermore, compared with previous models, it has important practical value not only because of strong theoretical foundation, but also for smaller amount of calculating work and convenient application in practice.
