State Key Laboratory of Water Resources and Hydropower Engineering Science

Wuhan, China

State Key Laboratory of Water Resources and Hydropower Engineering Science

Wuhan, China
SEARCH FILTERS
Time filter
Source Type

Yu X.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Yu X.,Hohai University | Zhang J.,Hohai University
Shuili Xuebao/Journal of Hydraulic Engineering | Year: 2016

Based on the one-dimensional hydraulic transients and the method of characteristics (MOC), the mathematical model of the vent in the tail race tunnel is established by using the Discrete Free-Gas Cavity Model (DGCM), and the thermodynamic properties of the gas is taking into account as well. A corresponding numerical model has been developed using the data of a real hydropower station, and the phenomenon of air inlet-two phase flow-air releases is investigated during transient process. The results show that air inlet can effectively relieve the negative pressure in the tunnel, but air releases can lead to a large impact pressure, which comes from the water column rejoin after the separation by the air, resulting in the direct water hammer. When the area of the vent is large, the impact pressure decreases with the increase of the area, when the area of the vent is small, the impact pressure increases with the increase of the area. According to its characteristics, the structure of a new type of vent is presented, i.e., the vent is fully open when the air flows in, and the vent is partly open when the air flows out. When the air releases area is about 10% of the air inlet area, the pressure oscillation is small. © 2016, China Water Power Press. All right reserved.


Chen Z.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Chen Z.,Wuhan University of Technology | Cui Y.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Liu F.,Jiang Xi Province Irrigation Experiment Station
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2013

Farmland soil is often in alternating wet and dry state, which seriously affected the change of soil composition and properties, and thus changed soil hydraulic properties. During the course of alternation of wetting and drying, along with the change of water content, soil bulk density would change accordingly. The experimental investigations of this paper were carried out in irrigation field of Jiangxi province irrigation experiment station. The rice planting field trials were launched by employing experimental treatment with two irrigation modes including flooding, intermittent irrigation and four fertilization mode including no nitrogen fertilizer, nitrogen-containing compound fertilizer, controlled-release nitrogen fertilizer, organic and inorganic nitrogen fertilizer. Through analyzing change of soil specific volume with water content of all the tested soil undisturbed soil, the method of statistical analysis was used to fit the soil quality index curve model of water content and soil specific volume relationship. And main influence factors of soil wetting expansion and drying shrinkage were obtained by gray correlation analysis. The results showed that the index model can be used to describe the soil expansion process and shrinkage process under different irrigation and fertilization modes. a (dry soil, reciprocal of dry soil volume mass) and b (the natural logarithm unit value of soil specific volume change when unit water content change) values in soil shrinkage characteristics curve index models of different irrigation and fertilization mode were not the same with responding expansion curve index models. Soil shrinkage curve and expansion curve were two mutually non-coincident curves, b values and their differences in two curves were also different and lag phenomenon was existed. Soil wet expansion and dry shrinkage characteristics were affected by a variety of soil properties, which was mainly reflected through the effect of pore structure in soil and water holding properties.


Li Y.Y.,Chinese Ministry of Water Resources | Cao J.T.,Chinese Ministry of Water Resources | Shen F.X.,Chinese Ministry of Water Resources | Xia J.,State Key Laboratory of Water Resources and Hydropower Engineering science | Xia J.,Chinese Academy of Sciences
Science China Earth Sciences | Year: 2014

Water is a critical natural resource upon which all social and economic activities and ecosystem functions depend. With a surprising social and economic development in the past decades, water has become an important constraint for China's sustainable development, and a matter concerning economic security, ecological security and national security of the country. Understanding the changes of water resources is greatly helpful in analyzing the impacts of climatic change, formulating plans for utilization and protection of water resources, and making water resource decisions. Based on China's national water resources assessment, the Mann-Kendall's test, and Morlet wavelet, we analyzed the changing trends and periods of China's renewable water resources during 1956-2010. The results as following: (1) There is no significant change trend of water resources on the countrywide scale during the period 1956-2010, the total water resources show a slight increasing trend, and the national annual average water resources during the period 1991-2010 increased by 1% relative to that of the period 1961-1990. (2) The changes of water resources in different level-I water resource regions vary significantly. Annual average water resources of the Haihe River and Yellow River regions in the northern China decreased 19% and 17% respectively in the past 20 years. Water resource increased in Southern and Northwestern rivers regions, particularly in the Northwest rivers region, with the increasing amplitude by nearly 10% in the past 20 years. (3) The inter-annual variation of national water resource became larger in the past 20 years, as compared with that of the period 1961-1990. The coefficients of water resource variation increased in Northwestern and Southwestern rivers regions, while the inter-annual variation tended to decrease in the Haihe and the Yellow River regions where significant decline of water resources happened. (4) A 14-year quasi-periodicity of the national water resource variation was detected, overlapping with various periodicities of water resources of different level-I water resource regions. Remarkable uniformity exists between the first or secondary primary periodicity of water resource variation in adjacent level-I water resource regions. © 2014 Science China Press and Springer-Verlag Berlin Heidelberg.


Fu L.,Hunan Electrical Science Research Institute | Kou P.G.,Hunan Electrical Science Research Institute | Cheng Y.G.,State Key Laboratory of Water Resources and Hydropower Engineering Science
Advances in Power and Energy Engineering - Proceedings of the 8th Asia-Pacific Power and Energy Engineering Conference, APPEEC 2016 | Year: 2016

The hydraulic turbine vibration is the most important factor influencing the safe operation of hydropower station. Because of the relatively wide vibration area, the regulating capacity of the Francis turbine has been greatly limited in the grid. In order to analyze the mechanisms of inducing vibration of the Francis turbine, the 3-D CFD model of Francis turbine has been established and analyzed using numerical simulation in this paper. And the results of CFD numerical simulation are compared with the data of field testing. Through the numerical simulation, the mechanisms of inducing vibration and the variation of the pressure fluctuation have been identified. And in this paper, the pressure fluctuation contours of Francis turbine has been drawn out by the calculation in 25 conditions and the study can guarantee the hydropower station’s safe and stable operation. © 2016 Taylor & Francis Group, London.


Cai X.,State Key Laboratory of Water Resources and Hydropower Engineering Science | He Z.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Tang S.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Chen X.,State Key Laboratory of Water Resources and Hydropower Engineering Science
Construction and Building Materials | Year: 2016

The abrasion erosion characteristics of concrete made from moderate heat Portland cement, fly ash, and silica fume were investigated via sandblasting test. In this study, the influences of fly ash, silica fume, impinging velocity and impinging angle on abrasion erosion resistance were taken into account. The test results indicated that the concrete fabricated with moderate heat Portland cement, fly ash and silica fume was applicable to the mass construction in need of either low hydration heat or high abrasion erosion resistance. The abrasion mass loss rate of concrete increased with the increasing of the impinging angle, and showed an exponential relation with the impinging velocity. Furthermore, the proposed method by Bitter and Neilson et al. was applied to analyze the abrasion erosion characteristics of concrete. The characteristics of each concrete mixture could be featured by four parameters (ε,φ,K, and n) according to this method, and they could be used for preliminarily predicting the abrasion erosion resistance of concrete. © 2016 Elsevier Ltd


Chen S.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Wang J.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Chen L.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Luo B.,State Key Laboratory of Water Resources and Hydropower Engineering Science
Shuili Fadian Xuebao/Journal of Hydroelectric Engineering | Year: 2013

In this model test, a micro acoustic doppler velocimeter was used as the main method for measurements of the structure of hydraulic jumps at Froude numbers of 1.49, 2.51 and 3.35. Turbulence energy dissipation rate is estimated with the inertial dissipation method, and hence the distribution of Kolmogorov's length scale both inside and outside the jump is obtained. It is shown that eddies in the lower range of Kolmogorov's length scale assemble more closely in the developing boundary layer, the recirculation region and the air-water turbulent shear layer, but then they gradually level off along with the jump moving towards downstream. Under this circumstance, Reynolds number, instead of Froude number, is a dominant factor. On the other hand, the Kolmogorov's length scale within the jump decreases nonlinearly with the growth of Froude numbers, and at the same time, these eddies increase in size more rapidly within a certain distance after the jump. Finally, the scale becomes nearly the same over a cross section at a distance of 2.5 times the jump length from the toe. © right.


Yang H.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Fang K.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Tu S.,State Key Laboratory of Water Resources and Hydropower Engineering Science
Advanced Materials Research | Year: 2011

An experimental program has been conducted to investigate the influence of limestone powder (LP) on fluidity, strength, and hydration of cement mortar. Four laboratory grinds were prepared using a ball mill. The relationship between roundness of the LP and water requirement of paste, fluidity and strength of mortar was studied. The influence of LP on hydration of cement was investigated. Hydration products were determined by X-ray diffraction (XRD) analysis. Test results show that the roundness of LP significantly affected the water requirement of paste, fluidity and strength of mortar. In addition, the sites for the nucleation and growth of hydration products, provided by LP, accelerate the hydration of cement at early ages. While the enhancement of cement hydration at later ages mainly due to the formation of calcium aluminate monocarbonate.


Liu X.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Xu H.,Yangtze River Scientific Research Institute
Applied Mechanics and Materials | Year: 2012

The river reach in the center of Chongqing City lied in the fluctuant backwater of the Three Gorges Reservoir, and it was also the junction reach of the Jialing River to the Yangtze River. It's flow conditions and sediment movement was very complex. In the Three Gorges Reservoir 175m experimental operation period, the inherent laws of flow and sediment transport of river reach was changing under reservoir regulation. Prototype measured data for 20 years was analyzed at Jiulongpo, Zhuerqi, Jinshaqi and Cuntan sections. The results show that the association with the local flow were strong for the average sedimentation intensity in Flood season and the average erosion intensity later Flood season at the four sections. Different sediment erosion and deposition intensity corresponding to the flow was presented. According to the curve of discharge and cross-section mean velocity at Cuntan hydrologic section, the cross-section mean velocity corresponding to each flow is determined. On this basis, Sediment erosion and deposition change of river reach is analyzed at Three Gorges Project 175m operation periods. © (2012) Trans Tech Publications, Switzerland.


Yang H.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Fang K.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Tu S.,State Key Laboratory of Water Resources and Hydropower Engineering Science
Advanced Materials Research | Year: 2011

The present study aims to investigate the opportunity to largely substitute low heat Portland cement of mass concrete with supplementary cementitious materials. The pozzolanic reaction of two types of supplementary cementitious materials, phosphorous slag powder and fly ash, were determined by X-ray diffraction, differential thermal analysis-thermogravimetry and scanning electron microscopy from 28 to 90 days. The properties of mortar and mass concrete containing 30% of supplementary cementitious materials were also investigated. Results showed that supplementary cementitious materials could decrease the amount of calcium hydroxide, fill the capillary pores, thus making the mortar and mass concrete more compact and durable. Long-term strength of mass concrete containing 30% of supplementary cementitious materials were comparable (or even better) than the control concrete (without supplementary cementitious materials) at constant workability, while the Young's modulus was lower than the control concrete.


Ma G.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Ma G.,Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering | Zhou W.,State Key Laboratory of Water Resources and Hydropower Engineering Science | Zhou W.,Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering | And 4 more authors.
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2011

A stochastic granule model is developed at mesomechanical level. A random distribution model for rockfill granule is generated by means of random simulation technique. In addition, the nonlinear contact algorithm is presented based on modified augmented Lagrangian algorithm. A simple linear softening damage model is employed to describe the stress and strain relationship of mesoscopic element, and the mechanical properties are distributed with a certain statistical function. The stochastic granule model of Maokou rockfill of Shuibuya rockfill dam is established. The simulated results show that the movement and deformation processes of rockfill granule agree well with the present experiments.

Loading State Key Laboratory of Water Resources and Hydropower Engineering Science collaborators
Loading State Key Laboratory of Water Resources and Hydropower Engineering Science collaborators