摘要:

This paper describes the application of a 2-D nested model in rectangular coordinates and an orthogonal boundary fitted grid (BFG) model to tidal motions in Singapore coastal waters. The basic mathematical model for shallow water waves in the BFG model is derived from the transformation of corresponding depthaveraged equations in rectangular coordinates. The curvilinear coordinate system is obtained from the solution of a grid generator based on the elliptic generation technique.

ISSN:0022-1686    

DOI:10.1080/00221689709498641

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

This study uses a two-dimensional eddy viscosity model to investigate the wind-induced entrainment in a twolayer stably stratified water basin. By changing the background stratification and surface shear stress, the calculated entrainment coefficientsEshow that when Richardson numberRi*is less than a critical Richardson numberRic, entrainment law is in the form ofE∝Ri*-1, WhenRi*>Ric, molecular diffusion can not be neglected. The value ofRicis around the order ofPe1/2, wherePeis the Peclet number. Furthermore, three different mechanisms (upwelling, longitudinal dispersion and vertical mixing) are observed in the numerical simulation. By analyzing the time scales of these mechanisms, the interaction among them can be explained. The interaction and the resulted entrainment coefficient are found to be dependent on the aspect ratio of stratified basin.

ISSN:0022-1686    

DOI:10.1080/00221689709498642

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The removal by turbulent convection of a denser, miscible liquid in an abrupt depression that forms a basin at the bottom of a watercourse by this flowing stream has been studied experimentally. Different cavity shapes were examined with various end wall slopes. The effect of these geometric features and the cavity aspect ratio can be summarized effectively by normalizing a non-dimensional purging velocity with the square of the densimetrie Froude number.

ISSN:0022-1686    

DOI:10.1080/00221689709498643

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The paper treats looped networks wich have concentrated outflows or uniform outflow along the length of each pipe. An improved model is presented for optimal desing of new or partially extended water distribution networks, which operate either by means of gravity or a pump system.The model is based on the method of linear programming and allows the determination of an optimal distribution of commercial diameters for each pipe in the network and the length of the pipes which correspond to these diameters. Also, it is possible to take into account the various functional situations characteristic found during exploitation.

ISSN:0022-1686    

DOI:10.1080/00221689709498644

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The nature of three-dimensional turbulent boundary layers (3DTBL) are discussed with the intention of applying them to the problems encountered in hydraulic engineering. After introducing the basic concepts of 3DTBL, various cross-flow and near-wall similarity models are described. A comparison between the flow situations commonly encountered in hydraulic engineering and in some other branches of fluid mechanics (which initially prompted the development of 3DTBL theories) is made to explore the possibilities of utilizing the 3DTBL theories in hydraulic engineering. There appears to be numerous opportunities to fruitfully apply 3DTBL theories in hydraulic engineering. One such application is presented in a companion paper.

ISSN:0022-1686    

DOI:10.1080/00221689709498645

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

A mathematical model of suspended solids discharge from impervious surfaces during storm events has been developed. The model continuously simulates two major processes of different time scales; solids build-up at impervious surfaces between two storm events, and solids wash-off from the surfaces during storm events. Buildup is modelled using the Sartor and Boyd equation (21) in which the amount of' solids available on the surface is an exponential function of antecedent dry weather period duration. The spatial distribution of solid particles over the street surface is also modelled, which is an innovation. The wash-off process is divided into three subprocesses that are modelled consecutively. A kinematic wave model is used for overland flow modelling. The particle entrainment into suspension is estimated by two methods. In one, the rainfall and overland flow effects are not separated and the total shear stress is used to predict entrainment. In the other, the rainfall and overland flow effects are treated separately and then summed. An original equation was developed for this method. The model is applied on two small experimental catchments, one at Miljakovac-Belgrade, Yugoslavia and the other in Lund, Sweden. The description and verification of the model are presented and discussed in the paper.

ISSN:0022-1686    

DOI:10.1080/00221689709498646

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Four governing equations are derived to describe the fluid transients and induced structural responses of a fluid-filled pipe system. The equations include the coupling terms related through Poisson's coefficient, friction, and fluid-conveying in the pipeline. The method of characteristics (for fluid transients) and finite element method (for structural analysis) are used. A feedback-loop-iteration approach is adopted to solve the coupled problem. A numerical example problem is presented to investigate the fluid-structural interaction responses. The characteristics of a secondary pressure waves riding on the principal transient waves are presented.

ISSN:0022-1686    

DOI:10.1080/00221689709498647

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221689709498648

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221689709498649

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221689709498650

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor