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HYDRODYNAMIC CHARACTERISTICS OF CHINESE STURGEON SPAWNING GROUND IN yangTZE RIVER

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Journal of Hydrodynamics 2008年第2期20卷 225-230页

作者： yang Yu YAN Zhong--min CHANG jian-bo nanjing hydraulic research institute Nanjing 210029 China State Key Laboratory of Hydrology-Water Resources and hydraulic Engineering Nanjing 210029 China College of Water Conservancy and Hydropower Engineering Hohai University Nanjing 210098 China institute of Hydro-ecology Wuhan 430072 China

Since the construction of the Gezhouba Dam on the yangtze River in 1981, it has been found that the Chinese Sturgeon, Acipensor sinensis, performs natural propagation annually in a narrow reach downstream close to the Gezhouba Dam site. This might allow one to better investigate the river hydrodynamic conditions of the Chinese Sturgeon spawning ground. In this article, spatial Kinetic Energy Gradient （KEG） and absolute value of vorticity were computed along the river sections from measured data. The relation between Spawn Density per Unit Area （SDUA） and vorticity strength and between SDUA and KEG were worked out. The Results showed that the vorticity and KEG were both effective parameters for describing the hydrodynamic characteristics of Chinese Sturgeon spawning ground. The Chinese Sturgeons prefer to spawn in the river sections where the value of vorticity strength is larger than 0.4 s^-1 and KEG is larger than 0.029 Jkg^-1m^-1.

关键词： hydrodynamic characteristics Chinese Sturgeon spawning ground vorticity kinetic energy gradient Spawn Densityper Unit Area (SDUA)

COUPLING EFFECT OF SEEPAGE FLOW AND RIVER FLOW ON THE BANK FAILURE

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Journal of Hydrodynamics 2011年第6期23卷 834-840页

作者： NING Bo wu- Shi-qiang TAN Ye-fei XIE Xing-hua YAN Jun YAN Zhong-min GENG Yan-qiong College of Water Conservancy and Hydropower Engineering Hohai University Nanjing 210098 China nanjing hydraulic research institute Nanjing 2100-29 China nanjing hydraulic research institute.nanjing 210029 China Lian Yungang Technical College Lian Yungang 222000 China

On the basis of the generalized physical model of the riverbank, the experiments were conducted to study the mechanisms of riverbank failure under the coupling effect of seepage flow and river flow. The experimental setup was specially designed, as well as test point location, parameters and procedures, and the main influencing factors were analyzed affecting riverbank failure based on the failure types, the variations of pore water pressure and soil displacement. The results indicated that the coupling effect has different influences on the bank failure in three aspects： the failure type, the process and the extent. In addition, the river flow played a more important role than the seepage flow in the coupling effect on the bank failure.

关键词： bank failure seepage flow river flow physical model test

Transmission of THz wave by liquid dielectric waveguide

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Science china(Technological Sciences) 2010年第6期53卷 1594-1597页

作者： ZHOU Lei,XU WeiWei,hua Tao,LU XueHui,CHEN jian,JIN BiaoBing,KANG Lin & wu PeiHeng research institute of Superconductor Electronics (RISE),nanjing University,nanjing 210093,china research institute of Superconductor Electronics (RISE) Nanjing University Nanjing China

The absorption and dispersion of several non-polar organic solvents from 0.2 to 2.5 THz are measured with the method of time-domain *** on the result,we believe that liquid paraffin might be a proper choice for liquid... 详细信息

关键词： THz liquid dielectric waveguide

EFFECTS OF ENTRAINED AIR MANNER ON CAVITATION DAMAGE

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Journal of Hydrodynamics 2011年第3期23卷 333-338页

作者： wu jian-hua LUO Chao College of Water Conservancy and Hydropwer Engineering Hohai University Nanjing 210098 China

Early in 1953 the experiments by Peterka proved that air entrainment has effects on decreasing cavitation damage. This technology has been widely used in the release works of high dams since the inception of air entrainment in the Grand Goulee Dam in 1960. Behavior, mechanism and application of air entrainment for cavitation damage control have been investigated for over half century. However, severe cavitation damage happened due to complex mechanism of air entrainment. The effects of air entrainment are related to many factors, including geometric parameters, hydraulic parameters and entrained air manners. In the present work an experimental set-up for air entrainment was specially designed, the behavior of reducing cavitation damage was experimentally investigated in the three aspects of entrained air pressure, air tube aera and air tube number. The results show that magnitude of reduction of cavitation damage is closely related to the entrained air tube number as well as entrained air pressure, air tube aera, and that the effect through three air tubes is larger than that through single air tube although the entrained air tubes have the same sum of tube aera, that is, 1 ＋ 1 ＋ 1 〉 3. Therefore, it is important to design an effective manner of air entrainment.

关键词： air entrainment air pressure air tube area cavitation damage entrained air manner

hydraulic CHARACTERISTICS OF PARTIAL OPENING OF THE WORKING GATE FOR A DISCHARGE TUNNEL

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Journal of Hydrodynamics 2007年第4期19卷 488-493页

作者： wu jian-hua FENG Shu-rong wu Wei-wei RUAN Shi-ping College of Water Conservancy and Hydropower Engineering Hohai University Nanjing 210098 China china Hydro Mid-South Design and research institute Changsha 410014 China

The partial opening of the working gate for a discharge tunnel is used more and more widely in the various conditions, such as releasing discharge to meet the needs of the various stages under construction, or of the operations at low reservoir levels. In this article the hydraulic characteristics were investigated of the partial opening of the working gate based on the physical model experiments of the discharge tunnel for the Longtan Hydropower Project, including the discharge coefficient, the surface profile of the free flow section, the bottom pressure distribution of the tunnel with an aerator, the cavity length just from the ramp, and the wall pressure of the curve section of the outlet. Some new issues were discussed and the properties were presented of the partial opening of the gate.

关键词： partial opening hydraulic characteristics working gate discharge tunnel

hydraulic CHARACTERISTICS OF BOTTOM UNDERLAY-TYPE PIER FOR WATER-WING CONTROL

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Journal of Hydrodynamics 2008年第6期20卷 735-740页

作者： wu jian-hua YAN Zhong-min College of Water Conservancy and Hydropower Engineering Hohai University Nanjing 210098 China

The pier, placed at the outlet of the pressure flow section, is an effective design to deal with the problems of the manufacture and operation of the gates fbr a discharge tunnel with high water head. It is crucial to control the water-wing, induced by this type of the pier. Through observing the phenomena of the water-wing, the reason of the water-wing inception, i.e., the concave of the flow surface, was presented, and a type of the new pier with bottom underlay was designed. The hydraulic characteristics of the pier, including the variations of the water-wing features, both length and height, with the water head, as well as with the concave depth, and with the height of the bottom underlay, and the variations of the concave depth with the height of the bottom underlay, were investigated by physical model experiments. The results show that the approach of the modification of the concave through the structures with the bottom underlay-type pier is remarkably effective in the water-wing control.

关键词： bottom underlay-type pier concave of flow surface discharge tunnel water-wing

EMERGENCE ANGLE OF FLOW OVER AN AERATOR

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Journal of Hydrodynamics 2007年第5期19卷 601-606页

作者： wu jian-hua RUAN Shi-ping College of Water Conservancy and Hydropower Engineering Hohai University Nanjing 210098 China

Aerator is an important device for release works of hydraulic structures with high-speed flow in order to protect them from cavitation damage. This kind of protecting effect is related closely to cavity length below the aerator, while the cavity length is dominated by the emergence angle over the aerator. Therefore it is crucial to determine this angle accurately. In the present paper the affecting intensities of flow depth and the fluctuating velocity on this angle were analyzed through two introduced parameters. Furthermore, the improved expressions of emergence angle estimation, for both ramp-type and step-type aerators, were presented by means of 68 sets of experimental data from 6 projects based on error theory. The results showed that the present method has higher accuracy than the previously reported methods.

关键词： aerator cavitation damage cavity length,emergence angle flow depth fluctuating velocity

FLOWS THROUGH ENERGY DISSIPATERS WITH SUDDEN REDUCTION AND SUDDEN ENLARGEMENT FORMS

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Journal of Hydrodynamics 2010年第3期22卷 360-365页

作者： wu jian-hua AI Wan-zheng College of Water Conservancy and Hydropower Engineering Hohai University Nanjing 210098 China

The energy dissipation of flood discharges has been one of important problems that affect directly the safety of hydropower projects. The energy dissipater with sudden reduction and sudden enlargement forms, used widely in large-scale projects has been a kind of effective structure for energy dissipation. The concept of critical thickness was defined, which is related to both the geometric parameters and the hydraulic parameters of the energy dissipater, and the factors affecting the critical thickness, were analzsed by means of dimensional analysis. The empirical expression about the critical thickness was obtained and could be used as the criterion to distinguish the flows through the energy dissipater, i.e., the plug flow and the orifice plate flow. The error analysis showed that the critical thickness calculated by the expression has the errors of smaller than 10% in the estimation of the flows for the energy dissipater mentioned above.

关键词： critical thickness energy dissipater orifice plate plug reduction ratio sudden reduction sudden enlargement

ANALYSIS OF WATER QUALITY IN SHALLOW LAKES WITH A TWO-DIMENSIONAL FLOW-SEDIMENT MODEL

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Journal of Hydrodynamics 2007年第4期19卷 501-508页

作者： JI Yong ZhANG Jie YAO ei ZHAO Di-hua Nanchang institute of Technology Nanchang 330099 China College of Environmental Science and Engineering Hohai University Nanjing 210098 China nanjing hydraulic research institute Nanjing 210098 China

The governing equation for sediment pollutions was derived based on the turbulent diffusion of pollutants in shallow lakes. Coupled with shallow water equations, a depth-averaged 2-D flow and water quality model was developed. By means of the conservation law, a proposed differential equation for the change of sediment pollutants was linked to the 2-D equations. Under the framework of the finite volume method, the Osher approximate Riemann solver was employed to solve the equations. An analytical resolution was used to examine the model capabilities. Simulated results matched the exact solutions especially well. As an example, the simulation of CODMn in the wuli Lake, a part of the Taihu lake, was conducted, which led to reasonable results. This study provides a new approach and a practical tool for the simulation of flow and water quality in shallow lakes.

关键词： sediment falling velocity turbulence flow and water quality model finite volume method approximate Riemann solver shallow water equation advection-dispersion equation