NUMERICAL MODELING OF WAVE EVOLUTION AND RUNUP IN SHALLOW WATER

Based on the Navier-Stokes (N-S) equations for viscous, incompressible fluid and the VOF method, 2-D and 3-D Numerical Wave Tanks (NWT) for nonlinear shallow water waves are built. The dynamic mesh technique is applied, which can save computational resources dramatically for the simulation of solitary wave propagating at a constant depth. Higher order approximation for cnoidal wave is employed to generate high quality waves. Shoaling and breaking of solitary waves over different slopes are simulated and analyzed systematically. Wave runup on structures is also investigated. The results agree very well with experimental data or analytical solutions.     

AN INVERSE PROBLEM OF WATER WAVE GENERATION IN A WAVE TANK

ＡＮＩＮＶＥＲＳＥＰＲＯＢＬＥＭＯＦＷＡＴＥＲＷＡＶＥＧＥＮＥＲＡＴＩＯＮＩＮＡＷＡＶＥＴＡＮＫＭｉａｏＧｕｏ－ｐｉｎｇ；ＹｏｕＹｕｎ－ｘｉａｎｇ；ＬｉｕＹｉｎｇ－ｚｈｏｎｇ（ＳｈａｎｇｈａｉＪａｏＴｏｎｇＵｎｉｖｅｒｓｉｔｙＳｈａｎｇｈａｉ２０００...     

NUMERICAL SIMULATIONS OF WATER WAVE DYNAMICS BASED ON SPH METHODS

A numerical model was established for simulating water wave dynamic problems by adopting the Smoothed Particle Hydrodynamics (SPH) methods of iterative solution of Poisson's equation for pressure field, and meanwhile the sub-grid turbulence model was applied in the simulation so as to more accurately describe the turbulence characteristics at the time of wave breaking. In this article, simulation of the problem of the dam collapsing verifies the compoting accuracy of this method, and its results can be identical with the results of VOF method and the experimental results by comparison. Numerical simulations of the course of solitary wave and cnoidal wave run-up breaking on beaches were conducted, and the results are basically consistent with experimental results. This indicates that the SPH method is effective for the numerical simulation of the complex problems of water wave dynamics.     

WAVE FORCES ON INCLINED CYLINDER IN REGULAR WAVES

Through a series of model tests,the wave forces on horizontal and inclined circularcylinders are measured and analyzed.Based on Morison Equation and Stokes second order wavetheory,the relationship between the hydrodynamic force coefficients with KC number and sub-merged water depth as well for horizontal cylinders are analyzed,also the relationship betweenthe hydrodynamic force coefficients with KC number,inclined angle and the effect of water freesurface as well for the inclined cylinders are investigated.     

DEFORMATION AND BREAKINC OF NONLINEAR WAVE IN WATER OF GRADUALLY VARYING DEPTH

Based upon the perturbation method,this paper used the method of conformalmapping to solve the deformation and breaking of nonlinear waves in water of gradually varyingdepth.The wave characteristics,such as wave deformation,velocity field,breaker type andbreaker height are discussed by the third order approximation.Results obtained are comparedwith experimental data.     

HYDRODYNAMICS THEORY AND CALCULATION IN WATER WAVE PUMP DESIGN

This paper introduces the hydrodynamics theory related to water wave pump. Water wave pump is a new type pump, which uses the particular quality of water wave and re-divides the inflow energy to increase the pressure of one part of the inflow water with the rest water flowing away freely. The research and development of such a pump is of importance and significant value and profitable social interest in that it can fully utilize the residual energy of natural source in industrial and civil water circle systems. Through hydrodynamies research and calculation, a series of valid design parameters were obtained and the predicted results achieved.     

WATER WAVE SIMULATION IN CURVILINEAR COORDINATES USING A TIME-DEPENDENT MILD SLOPE EQUATION

The purpose of this article is to model the detailed progress of wave propagation in curvilinear coordinates with an effective time-dependent mild slope equation. This was achieved in the following approach, firstly deriving the numerical model of the equation, i.e., Copeland's hyperbolic mild-slope equation, in orthogonal curvilinear coordinates based on principal of coordinate transformation, and then finding the numerical solution of the transformed model by use of the Alternative Directions Implicit (ADI) method with a space-staggered grid. To test the curvilinear model, two cases of a channel with varying cross section and a semi-circular channel were studied with corresponding analytical solutions. The model was further investigated through a numerical simulation in Ponce de Leon Inlet, USA. Good agreement is reached and therefore, the use of the present model is valid to calculate the progress of wave propagation in areas with curved shorelines, nearshore breakwaters and other complicated geometries.     

TURBULENT OPEN CHANNEL FLOW SUBJECTED TO THE CONTROL OF A SPANWISE TRAVELING WAVE

Turbulent open channel flows subjected to the control of a spanwise traveling wave have been investigated by means of Direct Numerical Simulation(DNS).The objective of this study is to reveal the response of the near-wall and surface-influenced turbulence to the spanwise traveling wave control.Three typical frequencies of the spanwise traveling wave,i.e.,high-,middle-and low-frequency,corresponding to the exciting periods at 25,50 and 100,are considered to study the turbulence dynamics in the wall and surface regions.To elucidate the behaviors of turbulence statistics,some typical quantities,including the mean velocity,velocity fluctuations and the structures of turbulence fluctuations,are exhibited and analyzed.     

三峡工程对库区水流水质影响预测

利用开发的三峡水库整体一维水流水质数学模型，对三峡水库建成前后的水流水质变化趋势进行预测分析。重点介绍三峡工程建成后，库区水流条件巨大变化对污染物输移转化特性和水质分布的影响。预测结果表明，三峡工程建成后，三斗坪水位175m条件下，回水区断面平均流速比建库前减小4倍左右，平均有机污染物自净降解速率和大气复氧速率比天然河道状况减小1倍。由于污染物在库区滞留时间成倍延长，有机污染物排入水库后的自净降解总量较天然河道状况增大，因而，建库后加水区内断面平均有机污染物浓度较天然河道状况明显下降，但是，断面平均溶解氧浓度与天然河道状况相比也明显降低，对于守恒类污染物，建库前后水质变化不大。因此，三峡工程对库区水质影响有利也有弊。     

NUMERICAL STUDY OF SQUARE-STERN SHIP WAVE IN SHALLOW WATER

This paper employed shallow water equations with moving pressure to calculate water waves generated by a square-stern ship in shallow water. The moving ship is considered as moving pressure on free surface. The finite element method with moving grids is used to solve the shallow water equations based on wave equation model [3]. A non-reflection boundary condition [5]is imposed on open boundaries surrounding the ship. 3-D surface elevations, depth-averaged horizontal velocities are presented. The numerical solutions are physically reasonable. It is found that wave resistance coefficients, draftchange and pitch angle vary rapidly in neighborhood of critical flow (Fh=u/ gh= 0. 9 -1. 1). The numerical results also indicate that the wave resistance coefficients, draft change and pitch angle of square-stern ship are larger than those of sharp-stern ship with the same hull structure at the same speed.     

THE EFFECTS OF RADIATION STRESS ON WAVE HEIGHTS AND SEA LEVEL IN THE INTERACTION OF COUPLED WAVE-TIDE-SURGE IN THE COASTAL AREA

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＷｉｎｄｇｅｎｅｒａｔｅｓｂｏｔｈｗａｖｅｓａｎｄｓｔｏｒｍｓｕｒｇｅｓ,ｓｏｔｈｅｉｒ ｇｅｎｅｒａｔｉｏｎｉｓｃｌｏｓｅｌｙｒｅｌａｔｅｄ .Ｆｕｒｔｈｅｒ ｍｏｒｅ ,ｓｔｒｏｎｇｌｙｎｏｎｌｉｎｅａｒｉｎｔｅｒａｃｔｉｏｎｓｂｅｔｗｅｅｎｔｉｄｅｓａｎｄｓｔｏｒｍｓｕｒｇｅｓｅｘｉｓｔｉｎｓｈａｌｌｏｗｗａｔｅｒ .Ｔｈｅｉｎｔｅｒａｃｔｉｏｎｓｂｅｔｗｅｅｎｗａｖｅａｎｄｔｉｄｅ ｓｕｒｇｅｍｏｔｉｏｎ ,ｂｅｔｗｅｅｎｗａｖｅａｎｄｔｈｅｍｅａｎｆｌｏｗｏｒｗａｔｅ…     

NUMERICAL SIMULATION OF THE VERTICAL IMPACT OF A SUPERSONIC FLAT-HEAD BODY ON A WATER SURFACE

By using PIC method ,the vertical impact on the water surface for a 2-D su-personic flat-head body with a detached shock wave is studied in this paper.Numerical resultsshow that various complicated flow phenomena such as the supersonic flow around the body,theair cushion effect,the propagation of the shock wave in water,the initial formation of the wa-ter-entry cavity and the pile-up of the water surface are simulated successfully.     

建设项目水资源论证应正确合理考虑生态需水

阐述了目前在建设项目水资源论证中,应该合理地考虑河流系统生态需水的必要性和重要性．结合实例介绍了河流系统生态需水的简单计算方法,并进行了综合分析,供同仁参考。     

EXPERIMENTAL STUDY ON THE VORTEX FORMATION AND ENTRAINMENT CHARACTERISTICS FOR A ROUND TRANSVERSE JET IN SHALLOW WATER

The vortex formation and entrainment characteristics for a round transverse jet in shallow water were experimentally investigated by means of a combination of LIF flow visualization and PIV measurement. A scarf vortex wrapped around the main body of the jet is formed in the near-wall region due to the interaction between the resulting wall jet and sufficiently shallow crossflow, with some more or less unsteady flow properties and with spreading ranges as functions of both the velocity ratio and the water depth within the near field. The entrainment of the ambient crossflow fluid into the jet main body is closely associated with the time-evolving features of the shear layer between the jet and surrounding fluid as well as the induced vortical structures near the wall. In the case of slight impingement upon the wall, the interaction between the jet shear layer and the weak, unstable scarf vortex gives rise to an appreciable local entrainment enhancement, confined in the near-wall region in the vicinity of the stagnation point. While in the case of intense impingement upon the wall, the well-organized and stable scarf vortex gives rise to a greatly enhanced entrainment and a greatly increased lateral spreading rate nearly throughout the overall near field as compared to the conventional wall jet. In addition, the entrainment of the ambient crossflow fluid by the scarf vortex in this case occurs largely on the surface of the unique spiral roller structure by itself due to the presence of smaller and unorganized eddies, and accordingly the scarf vortex is likely to keep its spiral roller structure steadily to a relatively great downstream distance within the near field.     

NUMERICAL STUDY ON EFFECT OF WAVING BED ON THE SURFACE WAVE

1. INTROUCTION There have been lot of researches on the effect of the bottom on the surface wave, in which, most of them involved the fixed bottom with concave, convex, or periodical shapes [1-3]. It seems that very few ones on waving bed are available up…     

ON BASIC EQUATIONS OF WATER HAMMER

ＯＮＢＡＳＩＣＥＱＵＡＴＩＯＮＳＯＦＷＡＴＥＲＨＡＭＭＥＲ￥ＹａｎｇＪｉａｎ－ｄｏｎｇ，ＷｕＲｏｎｇ－ｑｉａｏ（ＷｕｈａｎＵｎｉｖｅｒｓｉｔｙｏｆＨｙｄｒａｕｌｉｃａｎｄＥｌｅｃｔｒｉｃＥｎｇｉｎｅｅｒｉｎｇ，Ｗｕｈａｎ４３００７２，Ｐ．Ｒ．Ｃｈｉｎ...     

新干县蓄水工程灌溉水费征收探讨

对江西省新干县蓄水工程灌溉水费征收问题进行探讨，并提出了一些建议和对策。     

A HYBRID METHOD FOR THE SIMULATION OF WAVE SPECTRUM TRANSFORMATION AND BREAKING PHENOMENA ON A SLOPE

ＡＨＹＢＲＩＤＭＥＴＨＯＤＦＯＲＴＨＥＳＩＭＵＬＡＴＩＯＮＯＦＷＡＶＥＳＰＥＣＴＲＵＭＴＲＡＮＳＦＯＲＭＡＴＩＯＮＡＮＤＢＲＥＡＫＩＮＧＰＨＥＮＯＭＥＮＡＯＮＡＳＬＯＰＥＬｉＹｕ－ｃｈｅｎｇ；ＤｏｎｇＧｕｏ－ｈａｉ（ＤｅｐａｒｔｍｅｎｔｏｆＣｉｖｉｌ...     

SPECTRAL ANALYSIS OF RANDOM WAVE UPLIFT FORCE ON A HORIZONTAL DECK

This article presents a spectral analysis of wave uplift loads on a horizontal deck.The wave uplift force spectrum on the underside of the deck is obtained.It is shown that the wave uplift force spectral density decreases with the increase of the relative clearance1/3Δh /H.The influences of different incident wave parameters,including the relative wave height1/3H /d,the relativedeck width/sB L and the relative clearance1/3Δh /Hon the dimensionless zeroth spectral moment of the uplift forces arediscussed.It is found that the zeroth spectral moment of the uplift forces increases with the increase of the relative wave height1/3H /d,and decreases with the increase of the relative clearance1/3Δh /H.A new dimensionless prediction model for the zerothspectral moment of wave uplift loads on the deck is proposed and the relationship between the wave uplift forces and the zerothspectral moment of the uplift force are obtained.     

THE APPLICATION OF COKELET''''S WAVE THEORY IN THE CALCULATION OF WAVE-CURRENT FIELD

By using Cokelet's wave theory,the limiting wave height and the relative waveangular frequency in wave-current field were calculated in this paper.It is indicated by numeri-cal calculation that if the water depth is not too small,the result given by authors'calculationare very close to the results of limiting wave height by Dalrymple(1975)and to the data of rel-ative wave angular frequency by linear wave theory;but if water depth is rather small,thereare some discrepancy,