Entity

Time filter

Source Type


Yuan L.-R.,Sun Yat Sen University | Chen R.-L.,Pearl River Hydraulic Scientific Research Institute | Lu C.,Pearl River Hydraulic Scientific Research Institute
Applied Mechanics and Materials | Year: 2012

The mechanisms driving the salt flux in the Modaomen estuary were investigated using measurements from along-channel shipboard surveys over a spring-neap tide cycle. During the investigation, river discharge was controlled to increase sharply and then decrease gently. The measurement data were analyzed with composition method. The results show that exchange flow varied significantly over the spring-neap cycle, being weakest during middle tides and strongest during neap tides. It could be concluded that sub-tidal vertical shear dispersion, resulting from the estuarine exchange flow, is the dominant mechanism driving the salt flux since the salt flux resulting from vertical shear dispersion varies in amplitude by over an order of magnitude, which is close to two times as large as the variation of advective salt flux. Source


Lu C.,Changsha University of Science and Technology | Lu C.,Pearl River Hydraulic Scientific Research Institute | Yuan L.,Sun Yat Sen University | Gao S.,Pearl River Hydraulic Scientific Research Institute | And 2 more authors.
Shuikexue Jinzhan/Advances in Water Science | Year: 2013

A series of channel experiments were carried out to investigate salt intrusion lengths with different tide ranges. The experiments show that there is a critical tide range value, with which the salt intrusion length reaches its minimum. Tide range increasing results in rapidly decreasing salt intrusion length if tide range is smaller than the critical value, while salt intrusion length slowly increases with increasing tide range if tide range is higher than critical value. Analyses of fresh and salt water mixing based on the experiments data uncovered the essence of the phenomena: (1) The stratification is broken during the tide range changing, which changes the forces resulting in salt intrusion; (2) Gain of salt is mainly due to the exchange flow if fresh water and salt water is stratified, stronger tide strength could damp the stratification and reduce the exchange flow salt flux, causes smaller salt intrusion length; (3) While if fresh water and salt water is mixing well, gain of salt is mainly due to diffusion, stronger tide strength could provide stronger diffusion, causes longer salt intrusion length. Source


Lu C.,Changsha University of Science and Technology | Lu C.,Pearl River Hydraulic Scientific Research Institute | Liu X.-P.,Changsha University of Science and Technology | Lin J.-D.,Changsha University of Science and Technology | Chen Y.-J.,Changsha University of Science and Technology
2011 International Conference on Electric Technology and Civil Engineering, ICETCE 2011 - Proceedings | Year: 2011

In view of the poor characteristic of conventional all-vertical-piled wharf's ability of resisting horizontal loads,the paper put forward a new type of structure named mudsill all-vertical-piled and high-piled wharf. In order to study it's longitudinal and transverse transfer regulation of horizontal force under horizontal loads,The FEM software ANSYS is employed to analysis the interaction of pile and soil model in this paper. The paper put up the simulations of single frame structure model and jointed structures model. By analysing the lateral displacement, bending moment and shear force of piles, the text analyses the rule of force transmission and deformation mechanism of the mudisll all-vertical-piled and high-piled wharf under the horizontal force. © 2011 IEEE. Source


Yuan L.-R.,Sun Yat Sen University | Yang Q.-S.,Sun Yat Sen University | Chen R.-L.,Pearl River Hydraulic Scientific Research Institute | Guo Z.-R.,South China Institute of Environmental Sciences
Sichuan Daxue Xuebao (Gongcheng Kexue Ban)/Journal of Sichuan University (Engineering Science Edition) | Year: 2012

Based on momentum and salt conservation, a tidally averaged salt flux budget model, which is suitable for partially mixing estuary, was deduced and applied to analyze the relationship between sub-tidal salt intrusion length and tidal amplitude in the Modaomen Estuary. This model contains the loss of salt due to the river flow, gain of salt due to the exchange flow and diffusion. The model was proved by comparison the simulated results and investigation data. A group of numerical simulating experiments were carried out with the model. The results showed that the salt reached most far away from the estuary mouth with constant neap tides, while nearest with constant spring tides. The analytical results showed that salt flux gain was predominantly due to tidal diffusion during spring time, but diffusion flux degenerated fast from the estuary mouth to upstream and it was far smaller than river flux at the upstream station. While during neap time the exchange flow was the main mechanics to gain salt and although the salt flux by exchange flow degenerated also from the estuary mouth to upstream, but even at the most upstream station it was still lager than the loss due to river flow. So salt intruded much longer with small tide amplitude in Modaomen Estuary. Source


Lu C.,Changsha University of Science and Technology | Lu C.,Pearl River Hydraulic Scientific Research Institute | Liu X.-P.,Changsha University of Science and Technology | Chen R.-L.,Pearl River Hydraulic Scientific Research Institute | Gao S.-Y.,Pearl River Hydraulic Scientific Research Institute
Shuidonglixue Yanjiu yu Jinzhan/Chinese Journal of Hydrodynamics Ser. A | Year: 2014

Estuarine complex dynamic mechanism, eco-environmental fragility and the increasing of Pearl River Delta salt intrusion length year by year have caused tremendous impacts on the ecological environment. Salt intrusion length significantly is affected by runoff and tidal. This paper uses physical model test to analyze salt intrusion length under interaction between runoff and tidal. The results show that: 1) Increasing upstream runoff can increase hydraulic gradient to make hydraulic gradient down. 2) There is a critical tidal range, the salt intrusion length is shortest when the flood slack. 3) When the upstream increases the same runoff, the smaller tidal range the lower fresh-salt water interface. Finally, Fischer's layered-circulation figure illustrates the mechanism of the deviation generating. On the one hand when closing the small tidal range, it causes coefficient of layering change and us/uf variation amplitude greater, on the other hand, increasing runoff increases the density circulation transport proportion and reduces the turbulent diffusion transport proportion. When the tide range is small, the density circulation is the dominant factor. Increasing the transport proportion of the dominant factor causes the positive effect of superposition, on the contrary, large tidal range reduces this effect. Source

Discover hidden collaborations