A THIRD-ORDER BOUSSINESQ MODEL APPLIED TO NONLINEAR EVOLUTION OF SHALLOW-WATER WAVES

1.　INTRODUCTIONIncoastalandoceanengineering,thepredictionofwaverun-upwithadesirableaccuracyisoftenofparamountinterest.Previously,thesecond-orderBoussinesqmodel,whichassumesthatnonlinearanddispersiveeffectsarebothweakandofthesameorderofmagnitude,hasbeenextensivelyusedtostudytheevolutionofwavesinshallowwater(Peregrine,1967;MeiandUnliiata,1972etc.).Recently,theconventionalBoussinesqmodelhasalsobeenextendedtomodelwavesoveranintermediateorevenlargedepth,withinthescopeofasecond-ordertheory(wi…     

A HYBRID MODEL FOR THE MERGING OF JETS IN A COFLOWING AMBIENT FLUID

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＧｅｎｅｒａｌｌｙｔｈｅｄｉｓｐｅｒｓｉｏｎｏｆｊｅｔｓａｎｄｐｌｕｍｅｓｉｎａｍｏｖｉｎｇｅｎｖｉｒｏｎｍｅｎｔｃａｎｂｅｒｅｌａｔｅｄｔｏｔｈｅｄｉｓｐｏｓ ａｌｏｆｕｒｂａｎａｎｄｉｎｄｕｓｔｒｉａｌｗａｓｔｅｗａｔｅｒ     

NUMERICAL SIMULATION OF A MATHEMATICAL MODEL FOR WAVE PROPAGATION ON NON-UNIFORM CURRENT AND DEPTH

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＢｅｒｋｈｏｆｆ( 1 972 )ｄｅｒｉｖｅｄｔｈｅｗｅｌｌ ｋｎｏｗｎｃｏｍ ｂｉｎｅｄｒｅｆｒａｃｔｉｏｎ ｄｉｆｆｒａｃｔｉｏｎｅｑｕａｔｉｏｎｗｈｉｃｈｗａｓａｌｓｏｎａｍｅｄａｓｍｉｌｄ ｓｌｏｐｅｅｑｕａｔｉｏｎ .Ｔｈｅｅｑｕａｔｉｏｎｏｖｅｒ ｃｏｍｅｓｔｈｅｓｈｏｒｔｃｏｍｉｎｇｓｏｆｏｎｌｙｄｉｓｃｕｓｓｉｎｇｒｅｆｒａｃｔｉｏｎｐｈｅｎｏｍｅｎｏｎｆｏｒｔｈｅｒｅｆｒａｃｔｉｏｎｍｏｄｅｌａｎｄｏｎｌｙｓｔｕｄｙ ｉｎｇｄｉｆｆｒａｃｔｉｏｎｐｒｏｂｌｅｍｆｏ…     

COUPLING EFFECTS FOR CELL-TRUSS SPAR PLATFORM: COMPARISON OF FREQUENCY- AND TIME-DOMAIN ANALYSES WITH MODEL TESTS

For the floating structures in deepwater, the coupling effects of the mooring lines and risers on the motion responses of the structures become increasingly significant. Viscous damping, inertial mass, current loading and restoring, etc. from these slender structures should be carefully handled to accurately predict the motion responses and line tensions. For the spar platforms, coupling the mooring system and riser with the vessel motion typically results in a reduction in extreme motion responses. This article presents numerical simulations and model tests on a new cell-truss spar platform in the State Key Laboratory of Ocean Engineering in Shanghai Jiaotong University. Results from three calculation methods, including frequency-domain analysis, time-domain semi-coupled and fully-coupled analyses, were compared with the experimental data to find the applicability of different approaches. Proposals for the improvement of numerical calculations and experimental technique were tabled as well.     

COUPLING EFFECTS FOR CELL-TRUSS SPAR PLATFORM： COMPARISON OF FREQUENCY- AND TIME- DOMAIN ANALYSES WITH MODEL TESTS

For the floating structures in deepwater, the coupling effects of the mooring lines and risers on the motion responses of the structures become increasingly significant. Viscous damping, inertial mass, current loading and restoring, etc. from these slender structures should be carefully handled to accurately predict the motion responses and line tensions. For the spar platforms, coupling the mooring system and riser with the vessel motion typically results in a reduction in extreme motion responses. This article presents numerical simulations and model tests on a new cell-truss spar platform in the State Key Laboratory of Ocean Engineering in Shanghai Jiaotong University. Results from three calculation methods, including frequency-domain analysis, time-domain semi-coupled and fully-coupled analyses, were compared with the experimental data to find the applicability of different approaches. Proposals for the improvement of numerical calculations and experimental technique were tabled as well.     

NUMERICAL SIMULATION AND EXPERIMENTAL STUDY OF THE FLOW FIELD AROUND A CIRCULAR CYLINDRICAL ARTIFICIAL ISLAND UNDER THE ACTION OF WAVES AND VISCOUS CURRENT

ＮＵＭＥＲＩＣＡＬＳＩＭＵＬＡＴＩＯＮＡＮＤＥＸＰＥＲＩＭＥＮＴＡＬＳＴＵＤＹＯＦＴＨＥＦＬＯＷＦＩＥＬＤＡＲＯＵＮＤＡＣＩＲＣＵＬＡＲＣＹＬＩＮＤＲＩＣＡＬＡＲＴＩＦＩＣＩＡＬＩＳＬＡＮＤＵＮＤＥＲＴＨＥＡＣＴＩＯＮＯＦＷＡＶＥＳＡＮＤＶＩＳＣＯＵ...     

A COUPLED MORPHODYNAMIC MODEL FOR APPLICATIONS INVOLVING WETTING AND DRYING

This work presents a new finite volume Godunov-type model for predicting morphological changes under the rapidly varying flood conditions with wetting and drying.The model solves the coupled shallow water and Exner equations,with the interface fluxes evaluated by an Harten-Lax-van Leer-Contact(HLLC) approximate Riemann solver.Well-balanced solution is achieved using the surface gradient method and wetting and drying are handled by a non-negative reconstruction approach.The new model is validated against several theoretical benchmark tests and promising results are obtained.     

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

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.     

A LATTICE BOLTZMANN MODELING FOR THE WESTERN BOUNDARY CURRENT IN A LINEAR WIND-DRIVEN QUASI-GEOSTROPHIC MODEL

1 .　INTRODUCTIONLatticeBoltzmannMethod (LBM )isanewnumericalmethodforcomputationalfluid (ChenandDoolen 1998) ,whichisdevelopedfromLat ticeGasCellularAutomaton (LGCA )inthelate80satlastcentury .LBMusesthecontinuousdistri butionfunctiontoreplacetheBooleanvariablesusedinLGCA .Asaresult ,LBMovercomesmanyshortcomingsofitsancestor ,suchasnoise ,notconformingtoGalileoinvarianceetc .HeandLuo(1997)developedLBMasaself containedsystemconstructedtheamodelwithoutconnectiontoLGCA .LBMha…     

A COUPLED MODEL OF HYDRODYNAMICS AND WATER QUALITY FOR YUQIAO RESERVOIR IN HAIHE RIVER BASIN

In order to simulate the characteristics of hydrodynamic field and mass transport processes in the Yuqiao Reservoir （YQR）, a 2-D coupled model of hydrodynamics and water quality was developed, and the water-quality related state variables in this model included CODMn, TN and TP. The hydrodynamic model was driven by employing observed winds and daily measured flow data to simulate the seasonal water cycle of the reservoir. The simulation of the mass transport and transformation processes of CODMn, TN and TP was based on the unsteady diffusion equations, driven by observed meteorological forcing and external loadings, with the fluxes form the bottom of reservoir and the plant photosynthesis and respiration as internal sources and sinks. A finite volume method and Alternating Direction Implicit （ADI） scheme were used to solve these equations. The model was calibrated and verified by using the data observed from YQR in two different years. The results showed that in YQR, the wind-driven current was an important style of lake current, while the concentration of water quality item was decreasing from east to west because of the external pollutant loadings. There was a good agreement between the simulated and measured values, with the minimal calculation error percent of 0.1% and 2.6% and the mean error percent of 44.0% and 51.2% for TN and TP separately. The simulation also showed that, in YQR, the convection was the main process in estuaries of inflow river, and diffusion and biochemical processes dominate in center of reservoir. So it was necessary to build a pre-pond to reduce the external loadings into the reservoir.     

A NUMERICAL MODEL OF THE WEIS-FOGH MECHANISM WITH A SEPARATION VORTEX

ＡＮＵＭＥＲＩＣＡＬＭＯＤＥＬＯＦＴＨＥＷＥＩＳ－ＦＯＧＨＭＥＣＨＡＮＩＳＭＷＩＴＨＡＳＥＰＡＲＡＴＩＯＮＶＯＲＴＥＸＺｈａｎｇＳｈｅ－ｓｈｅｎｇ；ＷａｎｇＸｉａｎ－ｆｕ（ＷｕｈａｎＴｒａｎｓｐｏｒｔａｔｉｏｎＵｎｉｖｅｒｓｉｔｙ，Ｗｕｈａｎ４３００...     

THE APPLICATIONS AND STUDY OF NUMERICAL SIMULATION OF TURBULENCE FLOW WITH FREE SURFACE IN HYDRAULIC SPILL WAYS STRUCTURE

The turbulence flow Free Surface has important applications in hydraulic spillways structure,such as the hydraulic jump,energy dissipation flow etc.This is being considered as very complicated flow,and has not yet been solved quite well by numerical method. In this paper,a Large-scale computational software package are developed for numerical laboratory of hydraulic spillway structure.Some methods,such as turbulence model, free surface and irregular boundary treating techniques,scientific computer visualization are put forward and performed.     

A MATHEMATICAL MODEL OF MIGRATION AND EXPANSION OF MEANDER LOOPS

This article presents a mathematical model of the plane evolution of alluvial meandering streams,through downstream migration and lateral expansion of meander loops.Under the conditions prevailing in natural streams,the channel centerlines follow sine-generated curves,with an assumed steady-state turbulent and subcritical flow,of large width-to-depth ratio(≥ 15,for example) and small Froude number(Fr ).The plane deformation of the channel is caused by the action on the banks of the convective vertically-averaged meandering flow.The growth(migration and expansion) of meander loops is attributed to the regime-trend.The computational results of the model show that the obtained migration and expansion patterns of the meander loops are in good agreement with those of observations and measurements in similar meandering streams.     

THE SYSTEM OF MODEL CONTROL AND DATA ACQUISITION IN THE HUAIHE RIVER FLOOD CONTROL MODEL

ＴＨＥＳＹＳＴＥＭＯＦＭＯＤＥＬＣＯＮＴＲＯＬＡＮＤＤＡＴＡＡＣＱＵＩＳＩＴＩＯＮＩＮＴＨＥＨＵＡＩＨＥＲＩＶＥＲＦＬＯＯＤＣＯＮＴＲＯＬＭＯＤＥＬ￥ＣｈｅｎＸｉａｎ－ｐｕ；ＬｕＬｉｅ－ｍｉｎ；ＷｕＦｅｎｇ；ＬｉａｎｇＢｉｎ（Ａｎｈｕｉ＆Ｈｕａｉｈｅ...     

STUDY ON SIMILARITY LAWS OF A DISTORTED RIVER MODEL WITH A MOVABLE BED

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＩｔｉｓａｎｉｍｐｏｒｔａｎｔｓｕｂｊｅｃｔｉｎｒｉｖｅｒｍａｎａｇｅｍｅｎｔｔｏｐｒｅｄｉｃｔｔｈｅｂｅｄｄｅｆｏｒｍａｔｉｏｎｉｎａｌｌｕｖｉａｌｃｈａｎｎｅｌｓｉｎａｆｌｏｏｄ .Ｐｈｙｓｉｃａｌｍｏｄｅｌｓｈａｖｅｂｅｅｎｕｓｅｄｅｘｔｅｎｓｉｖｅｌｙａｓａｎｅｆｆｅｃｔｉｖｅｍｅｔｈｏｄ .Ｐｈｙｓｉｃａｌｍｏｄｅｌｓ ｐｅｒｍｉｔｔｈｅｐｒｅｄｉｃｔｉｏｎｏｆｔｈｅｃｏｒｒｅｓｐｏｎｄｉｎｇ ｐｒｏｔｏｔｙｐｅｆｌｏｗｓａｎｄｂｅｄｄｅｆｏｒｍａｔｉｏｎ ｑｕａ…     

模糊控制的预测模型及其应用

本文以青铜峡大坝变形观测资料为例 ,依据模糊控制理论 ,研究了用模糊聚类分析法建立复杂结构混凝土坝变形的预测模型。这对综合分析和评价复杂结构混凝土坝的变形性态具有较大的实用价值     

最优权组合模型与参数优化在安全监测分析中的应用

采用最优加权法配合参数优化建立组合预测模型 ,对某电站厂房机组平台作垂直位移分析。实例计算证实了所建模型的有效性 ,为一元或多元非线性建模提供了一条可行途径。     

A DYNAMIC MIXED MODEL WITH NITROGEN LEACHING LOSSES FROM THE PONDED PADDY RICE FIELD UNDER SITUATION OF BURIED PIPE DRAINAGE

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＤｕｒｉｎｇｔｈｅｇｒｏｗｔｈｏｆｒｉｃｅ ,ｔｈｅｐｏｎｄｅｄｐａｄｄｙｆｉｅｌｄｉｓｄｒｏｗｎｅｄｕｎｄｅｒｗａｔｅｒｓｕｒｆａｃｅｆｏｒａｌｏｎｇｐｅ ｒｉｏｄ .Ｄｕｅｔｏｔｈｅａｃｔｉｏｎｏｆｕｎｄｅｒｇｒｏｕｎｄｄｒａｉｎａｇｅｉｎｆｉｅｌｄｓ,ｔｈｅｓｅｅｐａｇｅｄｉｓｔａｎｃｅｉｓｓｈｏｒｔｅｎｅｄ ,ｔｈｅｐｅｒ ｃｏｌａｔｉｏｎｖｅｌｏｃｉｔｙ ,ｔｈｅｒｕｎｏｆｆ ｑｕａｎｔｉｔｙｏｆｕｎｄｅｒ ｇｒｏｕｎｄｄｒａｉｎａｇｅａｎｄｔｈｅｌｅａｃｈｉｎｇｌｏｓ…     

ON THE FILTRATION OF NON-NEWTONIAN FLUID IN POROUS MEDIA WITH A MULTIPLE PARAMETER MODEL

ＮＯＭＥＮＣＬＡＴＵＲＥＡＥｍｐｉｒｉｃａｌｃｏｅｆｆｉｃｉｅｎｔ ,ｋｇ/ (ｓｍ)ＢＥｍｐｉｒｉｃａｌｃｏｅｆｆｉｃｉｅｎｔ ,ｋｇｓｎ - 2 /ｍＣａｎｄＣ1ＩｎｔｅｇｒａｌｃｏｎｓｔａｎｔＣｔＴｏｔａｌｃｏｍｐｒｅｓｓｉｂｉｌｉｔｙ ,1/ＰａＣρＣｏｍｐｒｅｓｓｉｂｉｌｉｔｙｏｆｆｌｕｉｄ ,1/ＰａＣｒＣｏｍｐｒｅｓｓｉｂｉｌｉｔｙｏｆｒｏｃｋ ,1/ＰａｇＴｈｅｇｒａｖｉｔａｔｉｏｎａｌａｃｃｅｌｅｒａｔｉｏｎ ,ｍ/ｓ2ｈｅｆｆｅｃｔｉｖｅｔｈｉｃｋｎｅｓｓ ,ｍＨＣｏｎｓｉｓｔｅｎｃｙｏｆｐｏｗｅｒ ｌａｗｆ…