Zhejiang Institute of Hydraulics and Estuary
Zhejiang Institute of Hydraulics and Estuary
Mu J.,Zhejiang Institute of Hydraulics and Estuary |
Yin C.,Zhejiang Institute of Hydraulics and Estuary
River Sedimentation - Proceedings of the 13th International Symposium on River Sedimentation, ISRS 2016 | Year: 2017
The wave and tidal current are the important factors for the sediment transport of silt coast. United the third generation wave model SWAN for shallow water, this paper approximated the wave motion as time-averaged wave flow distribution field. And based on the wave flow radiation stress, a 2D mathematical model for sediment transport by wave and tidal current has been established. Based on triangle grid and finite volume method, The Roe scheme based on Riemann solver is used to compute the flux in the paper. The result shows that the wave is the main dynamics factor for the bedload movement. Wave-current interaction has a significant impact of sediment transport. The suspended sediment concentration increased more than 5 times when the typhoon land falling. And it the main cause of scour for the shoal area during typhoon. The model has been verified by the topographical data of trial dredging area at Cangnan thermal power plant. And it replayed the sudden sedimentation caused by typhoon. The research is very significance for the sediment transport of silt coast. © 2017 Taylor & Francis Group, London.
Li G.,Zhejiang Institute of Hydraulics and Estuary
IOP Conference Series: Earth and Environmental Science | Year: 2017
Two vegetation buffer zones (tree-shrub-grass pattern and tree-grass pattern) were selected as test objects around Siming reservoir in Yuyao City of China. The effect of the storm runoff intensity (low and high intensity) and the buffer zone width (1 m, 3 m, 5 m, 7 m, 9 m, 12 m, 16 m) on pollutants (suspended solids, ammonium nitrogen and total phosphorus) was studied by the artificial simulation runoff. The results showed that with the increase of the width of buffer zone, the pollutant concentration was decreased. The purification effect of the two buffer zones on suspended solids and total phosphorus was basically stable at 52-55% and 34-37%, respectively. But the purification effect on ammonium nitrogen was the tree-shrub-grass pattern (69.7%) significantly better than that of tree-grass pattern (52.1%). The purification rate at the low runoff intensity was 1.8-2.0 times that at the high runoff intensity. The relationship between the purification rate and buffer zone width can be expressed by the natural logarithm equation, and the model adjustment coefficient was greater than 0.92. © Published under licence by IOP Publishing Ltd.
Li Y.,Zhejiang University |
Pan D.-Z.,Zhejiang Institute of Hydraulics and Estuary
Renewable and Sustainable Energy Reviews | Year: 2017
China's major development and construction in utilization of tidal energy resources are concentrated in the area of Zhejiang Province. The development of tidal barrage in Zhejiang Province presented the ebb and flow trends. This paper introduced the resource status of tidal energy in Zhejiang Province. The five development stages of tidal barrage technology and the profiles of tidal power plant (TPP) in operation were reviewed, and problems and experiences were discussed. Some available future works for the development of tidal barrage were also proposed. The direction of utilizing tidal potential energy in the future is to update the generating units, improve construction skills and run optimization of operation in order to reduce costs and mitigate the impact on the environment. Actively exploring construction methods of medium to large-scale of TPPs are helpful to accelerate the utilization of tidal energy resources in Zhejiang Province and coastal areas in China. © 2017 Elsevier Ltd
Fu L.,Zhejiang Institute of Hydraulics and Estuary |
Jin Y.-C.,University of Regina
Engineering Applications of Computational Fluid Mechanics | Year: 2017
This paper presents a new macroscopic mesh-free particle method in which Darcy’s and Forchheimer’s terms are introduced into the governing equation to ensure the capacity of the particle method in simulating laminar and turbulent porous medium flows. A developed interfacial condition and inflow boundary condition are implemented in the macroscopic particle method to improve the stability of the Particle-based model. The comparisons of channel flow over and within porous bed among the present method, previous mesh-based method, and experimental data show that the macroscopic particle method is capable of simulating flows in both the clear flow region and porous flow region. Finally, two cases of flow over a rigid box and a cylinder lying on porous bed are simulated, and the numerical results are in good agreement with the measured data. The analysis and comparisons indicate that the newly developed particle-based method is reliable and has been successfully extended to macroscopic porous medium simulation. © 2017 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group
Pan C.,Zhejiang Institute of Hydraulics and Estuary |
Huang W.,Florida State University |
Huang W.,Tongji University
Journal of Coastal Research | Year: 2010
Study of suspended sediment transport in an estuary affected by tidal bore is important for coastal engineering and management because the tidal bore can cause strong sediment resuspension and scour in shallow waters. Numerical modeling of suspended sediment transport in a natural estuary affected by tidal bore is such a challenging research topic that there are few articles on the subject available in the literature. In this study, a two-dimensional, numerical model was developed to investigate suspended sediment transport induced by a tidal bore. The hydrodynamic component of the model employs the Godunov-type scheme with second-order accuracy in space, which effectively describes the rapid supercritical flow and sharp horizontal pressure gradients of the tidal bore. To preserve balance between the source terms and the internal forces, both the water levelbottom topography formulation (WLTF) method and a special technique for triangular mesh have been applied to solve the source term in the model equations to account for the irregular bottom topography. The wet/dry boundary issue was solved by using the improved exact-Riemann solver on the dry bed. The coupled sediment transport model incorporates more reliable equations from recent publications to characterize the rapid increase of sediment resuspension in the water column. The model test against an analytical solution of convection transport shows that the sharp gradient of scalar transport is satisfactorily estimated in the model simulations. The model in the application has been validated to simulate hydrodynamics and suspended sediment transport affected by a tidal bore in the Qiantang River of China. The results compare well with a time series of observations to characterize the rapid increases of surface elevation, currents, and suspended sediment concentration resulting from the tidal bore. Results of spatial distributions of water levels and currents indicate that the model adequately describes the sharp horizontal gradients of the surface elevation and the tidal currents during the passage of the tidal bore and characterizes the suspended concentrations in the estuary. © 2010 the Coastal Education & Research Foundation (CERF).
Qu L.,Zhejiang Institute of Hydraulics and Estuary |
Qu L.,Tsinghua University
Shuikexue Jinzhan/Advances in Water Science | Year: 2011
In order to resolve the issue concerning the relation of total dissolved gas(TDG) supersaturation and suspended sediment concentration of high-dams, a practical abatement measure for TDG supersaturation is put forward in this study. Based on a series of experiments, the production and release of TDG supersaturation in sediment laden flow are studied. The result shows that the production of TDG supersaturation remains almost the same level in either sediment laden flow or clear water for the same initial conditions. The rate of release of TDG supersaturation in sediment laden flow is significantly faster than that in clear water. The suspended sediment concentration can be increased through the use of bottom intakes, speeding up the release of TDG supersaturation. Such a measure can minimize the effect of TDG supersaturation on fish species in the downstream region of high-dams.
Xu C.,Hohai University |
Xu C.,Zhejiang Water Conservancy and Hydropower College |
Yue D.,Hohai University |
Deng C.,Zhejiang Institute of Hydraulics and Estuary
Engineering Applications of Artificial Intelligence | Year: 2012
Multicollinearity and difficulty of interpreting the coefficients of dam regression models pose two problems: (1) selection of informative variables for analysing dam deformation behaviour, and (2) mitigation of the multicollinearity among the variables. Resolving these two problems necessitates the application of genetic algorithm-based partial least square (GA-PLS) and statistically inspired modification of PLS algorithm (SIMPLS). A SIMPLS regression with the predictor variables selected by GA-PLS (hybrid GA/SIMPLS regression) is put forward to interpret the results obtained from periodic monitoring surveys of hydraulic structures. The hybrid model is employed for analysing the crack behaviour of an earth-rock dam in China. The results show the proposed model is superior to an ordinary SIMPLS and stepwise regression, especially when multicollinearity and influential outliers exist among the variables. Crown Copyright © 2011 Published by Elsevier Ltd. All rights reserved.
Xiong L.-H.,Zhejiang Institute of Hydraulics and Estuary |
Lu J.-J.,East China Normal University
Wilson Journal of Ornithology | Year: 2013
We studied exploitation of reedbeds by two specialist passerines, Reed Parrotbill (Paradoxornis heudei, listed as Near Threatened by the IUCN) and Oriental Reed Warbler (Acrocephalus orientalis), nesting in a tidal reedbed in the Changjiang River Estuary. Reed Parrotbills have significantly shorter, wider, and deeper bills than Oriental Reed Warblers. We distinguished >12 nest material categories in four groups (Phragmites, Zizania, artificial, and other) in nests of the two species. Reed Parrotbills used significantly fewer nest material categories, and had lower nest material diversity and a narrower nest material niche than Oriental Reed Warblers. More than 89% of the nest mass of Reed Parrotbills was Phragmites and was obtained from within the nesting habitat. More than 71% of the nest mass of Oriental Reed Warblers was Zizania from outside the nesting habitat. Most Phragmites material used by Reed Parrotbills was living tissue from reed leaf sheathes and stems. The large bill of the Reed Parrotbill facilitates exploitation of tissues from living reed shoots for nest materials, while the relatively long and slender bill of the Oriental Reed Warbler constrains it to use living reed shoots and exploit nest material from outside of nesting habitats. This is similar to their exploitation of food resources in reedbeds: Reed Parrotbills extract concealed insects within reed shoots while Oriental Reed Warblers glean exposed arthropods on a variety of plants. We confirm that food resource exploitation by Reed Parrotbills and Oriental Reed Warblers demonstrates a relationship between bill morphology and feeding as well as nest building. © 2013 by the Wilson Ornithological Society.
Xie D.-F.,Zhejiang Institute of Hydraulics and Estuary |
Pan C.-H.,Zhejiang Institute of Hydraulics and Estuary
Journal of Hydrodynamics | Year: 2013
In this paper, the turbulence characteristics of the tidal flow in the Qiantang River, China, the world-famous Qiantang bore, are studied. A detailed field observation at the Yanguan section of the Qiantang River was carried out during the spring tide in October 2010 with a continuous collection of high frequency turbulence data. The data analysis shows that the hydrodynamic processes are characterized by a strong tidal bore. Statistics of the turbulence such as the probability distributions of the turbulent components, the variance terms and the covariance terms are found consistent with those of previous studies of estuaries without the tidal bore. However, along the vertical profile, the distributions of all variables become more scattered downwards. The horizontal turbulence fluctuations are of a similar magnitude while the vertical turbulence has a fluctuation magnitude about 1/3 of that of the horizontal turbulences. The fluctuation strengths and the Reynolds stresses are much larger than those of other estuaries when the bore arrives. The bottom shear stress varies periodically with the tides, less than 0.44 N/m2 during the ebb but is increased drastically at the bore arrival, with the maximum being 0.92 N/m2. A good linear relationship is found between the bottom shear stress and the bottom suspended sediment concentration. © 2013 Publishing House for Journal of Hydrodynamics.
Sun M.-M.,Zhejiang Institute of Hydraulics and Estuary |
Sun M.-M.,Zhejiang Provincial Key Laboratory of Hydraulics Disaster Prevention and Mitigation
Yantu Lixue/Rock and Soil Mechanics | Year: 2014
A theoretical methodology which can calculate multiple scattering of plane SH waves by arbitrarily arranged and configuration of multi-row tubular piles is achieved. It can be considered the commonly so-called single scattering as the first order of multiple scattering. The second order of scattering of certain tubular pile is derived from incident waves which are excited from the first order of scattering by all tubular piles, which are also be regarded as the secondary waves by the first scattering. The rest scattering process of multiple order can be considered in the same manner. Assuming that every scattering order at pile-soil interface and interior of tubular pile are satisfied the elastic boundary conditions, the incident, scattering and transmitted waves are expanded in wave functions with Graf's addition theorem so that the undetermined scattering (transmitted) complex coefficients are obtained. Theoretical solutions of total scattering and transmitted wave fields inside the tubular piles are achieved. The influences of multiple scattering orders, ratios of the pile radius and distance between piles (or pile rows), shear modulus ratios of pile and soil, ratios of internal and external radius of tubular piles, geometric parameters of multi-row tubular piles etc. on screening effectiveness is discussed with numerical examples. The results show that tubular piles can achieve better screening effects than solid piles do. Several valuable reference bases of engineering design with discontinuous barriers made by tubular piles are delivered consequently.