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CHARACTERISTICS OF FLOW RESISTANCE IN OPEN CHANNELS WITH NON-SUBMERGED RIGID VEGETATION

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Journal of Hydrodynamics 2008年第2期20卷 239-245页

作者： WU Fu-sheng Nanjing Hydraulic Research Institute Nanjing 210029 China State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Nanjing 210029 China

The flow resistance factors of non-submerged rigid vegetation in open channels were analyzed. The formulas of drag coefficient CD and equivalent Manning＇s roughness coefficient na were derived by analyzing the force of the flow of non-submerged rigid vegetation in open channel. The flow characteristics and mechanism of non-submerged rigid vegetation in open channel were studied through flume experiments.

关键词： characteristics of flow resistance non-submerged rigid vegetation drag coefficient equivalent Manning's roughness coefficient

The Optimum Dosage Regimen of Intravenous Infusion for Drugs Obeying Parallel First-order and Michaelis-Menten Elimination Kinetics

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生物数学学报 1996年第4期11卷 6-11页

作者： Ding Yong（Department of Biomathematics，Nanjing Medical University，Nanjing 210029）

For drugs obeying parallel first-order and Michaelis-Menten elimination kinetics,mathematical analysis concerning the optimum dosage regimen of intravenous infusion is conducted and following equations are derived:where Xo is the intravenous loading dose,Cb the plasma concentration level desired in clinical therapy,V the apparent distribution volume,k0 the rate constant of intravenouns infusion,K the first－order elimination rate constant,Vm the theoretical maximum rate of the Michaelis－Menten elimination process,Km the Michaelis *** this dosage regimen,plasma level maintains a constant Cb during the administration *** K=0 the dosage regimen above is also suitable for drugs obeying Michaelis-Menten elimination kinetics.

关键词： Intravenous infusion Optimum dosage regimen Michaelis-Menten elimination kinetics Mathematical analysis

Sediment Transport Investigation in the Yangtze Estuary with Radioactive Tracer

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China Ocean Engineering 1992年第4期7卷 471-482页

作者： Li Zhangsu Senior Engineer, Nanjing Hydraulic Research Institute, 210029, Nanjing

This paper describes a radioactive tracer experiment carried out at the landward spoil site of the North Passage in the Yangtze Estuary in June, 1991. Scandium -46 was selected as the tracer, the total activity released was 179.45 GBq and the amount of the Sandium-46 glass was 495 g. The purpose of the experiment was to determine the sediment movement direction, path, velocity and transport rate, and therefore, to provide direct evidence for using the landward spoil site in the future. The experimental results showed that the sediment movement was governed by the ebb tide current during the period of mean and neap tides when the radioactive tracer was injected both on the flood and ebb tides, and the sediment moved from the release point to the middle of the North Passage near navigation buoy No. 269. The direciton of the sediment movement was 110 ° , the particle velocity was 758 m/d, and the sediment transport rate per unit width was 47.8 m3 / md.

关键词： radioactive tracer sediment transport estuary injection centroid mobile layer thickness

NUMERICAL SIMULATION OF SCOURING PROCESS UNDER SPILLWAY

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Journal of Hydrodynamics 2001年第4期13卷 55-59页

作者： Yang Jian-ming, Wu Jian-hua Nanjing Hydraulic Research Institute, Nanjing 210029, China Nanjing Hydraulic Res. Inst. Nanjing 210029 China

The scour problem under spillway has received a lot of attention in the past decades. For such a complicated problem, most numerical modeling presented only dealt with the water flows in equilibrium scour pools without considering the changing topography of the riverbed. In this paper, the dynamic process is handled with moving grids, and the governing equations are solved using finite volume method with colocated variable arrangement on boundary-fitted non-orthogonal grids. The results show that the given method is efficient, with which the variation of flow parameters, such as mean velocity and mean pressure, etc., can be computed correctly.

关键词： scour pool numerical simulation space conservation law moving grids

Design of Distorted Wave Protection Armor Units

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China Ocean Engineering 1992年第4期7卷 445-454页

作者： Lou Hongen Senior Engineer, Nanjing Hydraulic Research Institute, 210029, Nanjing Nanjing Hydraulic Research Institute 210029 Nanjing China China

In consideration of the global optimization for engineering projects, a group of calculation formulas have been derived by means of theoretical derivation and model tests. On this basis, a design procedure for the distorted units is proposed, by means of which the distorted units of an anology shape and an identical porosity ratio with the original units can be obtained after conducting a distorted enlargement and a normal contraction. The stability waveheight and stability factor of the distorted unit can be calculated with the enlargement factor, a, of the horizontal dimension of the distorted unit, or with the contraction scale, A , of the contracted distorted unit. As a result, the stability of the armor unit can be significantly improved without increasing the quantity of concrete. For the same wave met by the original units, the thickness of placement of the contracted distorted unit can be obviously reduced, thus, a large quantity of concrete can be saved, consequently, economic benefit can be achieved.

关键词： armor unit breakwater design structure wave protection

STUDIES ON GREY MODEL DYNAMIC PREDICTION TO CAVITATION DAMAGE OF TURBINES

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Journal of Hydrodynamics 2003年第5期15卷 29-34页

作者： Wu Fu sheng, Tong Zhong shan, Li Yun hui Nanjing Hydraulic Research Institute, Nanjing 210029, China Nanjing Hydraulic Res. Inst. Nanjing 210029 China

In thus paper, cavitation damage of turbines is firstly analyzed andpredicated from the view point of system engineering by use of the grey system theory. A detaileddescription of modeling, dynamic prediction and accuracy test for the grey system of turbines wasgiven. Two special cases for grey dynamic prediction as well as its accuracy test were *** results fall into the grade I, the accuracy is satisfactory and its prediction requirements canbe met well. It shows that the grey system theory can be employed to predict the cavitation damageof turbines, and it can provide a scientific basis for timely investigation and maintenance ofturbines.

关键词： turbine cavitation damage grey prediction

Influence of Approach Channel on Wave Propagation with Varying Incident Angles

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China Ocean Engineering 1996年第3期11卷 323-331页

作者： Zuo Qihua and Yang Zhengji . Senior Engieer, River and Harbour Department, Nanjing Hydraulic Research Institute, Nanjing 210029 River and Harbour Department Nanjing Hydraulic Research Institute Nanjing 210029

The variation of the amplitude of waves with varying incident angles when waves propagate through a typical approach channel is discussed by a numerical calculation method, the result of which shows that the influence of the channel on wave propagation is obvious. When the wave propagation direction is in coincidence with the channel axis, the wave amplitude ratio will decrease with the increase of propagation distance. When the incident angle is 15 - 30 , there appears an area of larger wave amplitude ratio on the side slope facing the waves, but at the another side, the wave amplitude ratio is generally small, indicating that the channel has a shielding effect. When waves propagate across the channel perpendicularly, the wave amplitude ratio can be calculated with the shallow water coefficient.

关键词： approach channel water wave varying incident angles numerical computation

Quality Assessment of Concrete Blocks Exposed in Nature for Eighty Years

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China Ocean Engineering 1992年第4期7卷 455-470页

作者： Hu Yuchu , Wu Shaozhang Lu Liyun Senior Engineer, Nanjing Hydraulic Research Institute, 210029 Nanjing Professor and Senior Engineer, Nanjing Hydraulic Research Institute, 210029 Nanjing Assistant Engineer, Nanjing Hydraulic Research Institute, 210029 Nanjing Nanjing Hydraulic Research Institute 210029 Nanjing China China

The concrete blocks used on a jetty in Shanghai were made in 1909 and 1910. Having been exposed in nature for 80 years, now there are 4600 pieces of blocks left on the jetty. Comprehensive inspections, such as external appearance examination, core-drilling of concrete blocks, ultrasonic detection, nuclear densimeter inspection and in-door and out-door chemical analysis, show that 75% of the blocks are of the rebound number of 21 - 23, and the saturated limit compressive strength and dry limit compressive strength of 10MPa; the carbonized depth of concrete is 1 - 2 mm. Compared with the state of the jetty in 1968, already used for 60 years then, the jetty is expected to serve another 40 years or more after being repaired.

关键词： jetty concrete block damage inspection durability

Interaction Between Pile-Supported Pier and Bank Slope

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China Ocean Engineering 1992年第2期7卷 201-214页

作者： Wei Rulong , Wang Nianxiang Yang Shouhua Prof., Senior Engineer, Nanjing Hydraulic Research Institute, 210029 Nanjing Engineer, Nanjing Hydraulic Research Institute, 210029 Nanjing Nanjing Hydraulic Research Institute 210029 Nanjing China China

- Generally the toe of the bank slope in front of the pile- supported pier has to be dredged to meet the requirements of water depth for the berth of ships, while the top of the slope in rear of the pier must be backfilled and elevated to make connections with land transportation. Then the natural state of equilibrium of the slope is destroyed, and some deformation and displacement are unavoidably induced in the soil mass which will exert an undesirable influence on the pile foundation of the pier. This is a typical problem of the interaction between the so-called 'passive pile' and surrounding soil, and has been scarcely studied in the literature of geotechnical engineering. In this paper, field observation, model tests and numerical analysis conducted by the authors to study the interaction between pile-supported pier and bank slope are briefly described and some preliminary results are presented.

关键词： interaction passive pile pier slope