摘要:

The radial hydraulic jump has been simulated using a strip integral mathematical model. The model is calibrated against the writers' experimental data. The strip integral method uses velocity shape functions to permit the partial integration of the equations of motion. A Gaussian velocity distribution is used in the mixing zone and the power law is used in the inner layer. The mathematical model includes the bed shear, turbulent shear, the potential core, entrained air, centrifugal force and turbulence pressure. The strip integral method has been applied to obtain a set of first order ordinary differential equations to describe the internal velocity distribution and water surface profile for a diverging radial hydraulic jump. These differential equations are solved by a fifth order Runge-Kutta method.

ISSN:0022-1686    

DOI:10.1080/00221689209498931

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The effect of a continuous, transverse sill on the hydraulic jump in a rectangular channel is analysed. Based on the results pertaining to the classical jump, the sill-controlled jump may be shown to correspond to a perturbed classical jump, particularly as regards the overall jump pattern. A novel normalisation procedure is introduced by referring to the roller length of classical jump. Further, the two- and three-dimensional flow patterns are discussed. The design procedure involves both the hydraulics and the erosion sensitivity of tailwater bed.

ISSN:0022-1686    

DOI:10.1080/00221689209498932

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The classification of rapidly varied unsteady flow is reviewed from continuity and momentum equations. Non-dimensional equations are proposed for analysing the combinations of sub- or supercritical regimes in the up- and downstream flow in a surge. A continuous profile or an alternative surge combination is found whenFr>2. It is shown that a simpler approach of the roll wave phenomenon can be obtained from a finite momentum equation.

ISSN:0022-1686    

DOI:10.1080/00221689209498933

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The calculations of transient hydrodynamic forces acting on dams subjected to arbitrary earthquakes are considered. A simple computational method based on the unit force hydrograph and the principle of linear superposition is proposed. The unit force hydrograph is calculated from analytic solution of a unit earthquake with a unit duration. Two test examples of earthquakes, one a linear earthquake with a finite duration and the other the EL Centro earthquake, are considered. The present results are compared with other analytic hydrodynamic solutions, and the comparisons show that the present computational method can predict very well the hydrodynamic forces acting on dams.

ISSN:0022-1686    

DOI:10.1080/00221689209498934

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

An implicit numerical method has been developed to solve the complete one dimensional shallow water equations. The principal advantage of the scheme is that for computations involving an advancing or receding wave front on a dry bed, it automatically guards against values of the water depth becoming unrealistically negative. Without any ad hoc assumption on the flow condition near a water-land boundary, it avoids difficulties in the computation of the flow field when zero water depths are involved. The algorithm has been tested by the computation of surge waves following a dam break, propagating on wet and dry channel beds. Exact solutions and some recently published numerical algorithms pertaining to this problem as well as available experimental data have been used for purposes of verification of the present scheme. Satisfactory comparisons have been obtained.

ISSN:0022-1686    

DOI:10.1080/00221689209498935

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Experimental data obtained on a laboratory test facility for unsteady flows in straight and curved channels and on the transient reservoir depths following a simulated dam failure are presented. The water level variation was recorded at five stations in the downstream channel and at six locations in the reservoir. In addition, plan views of the wave fronts were recorded at three stations in the downstream channel. Capacitance probes were used to measure water levels in the reservoir and a procedure using video cameras was developed to record water levels in the channel. Using this procedure, the flow was not disturbed. Video images of the waves were electronically converted into digital information based on their shading density. Tests were conducted for a wide range of initial conditions by varying the upstream reservoir depth, the channel depth, and the channel roughness. Complete test data for two tests are presented.

ISSN:0022-1686    

DOI:10.1080/00221689209498936

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The results of model experiments are described on the effect of an air-core vortex on pressure fluctuations within the tunnel of a hydroelectric river diversion installation. Data from sets of pressure transducers within the tunnel have been analyzed and it is shown that the presence of an air-core vortex leads to significant increases in (i) the dominant frequency of the pressure fluctuations and (ii) the strength of the pressure fluctuations within the tunnel. The implications of the results for the cavitation characteristics of the system are discussed.

ISSN:0022-1686    

DOI:10.1080/00221689209498937

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The statistical properties of the downstream propagation speed of the alluvial bedforms and the associated progression speeds of the individual sediments were evaluated on the basis of a series of radio-active tracer sxperiments conducted in a laboratory flume over a fairly broad range of flow conditions in which dunes were observed. The probability density functions for the progression speeds of the sediment motion were derived and found to fit well with the tracer results.

ISSN:0022-1686    

DOI:10.1080/00221689209498938

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

DRAG ON VERTICAL SILL OF FORCED JUMP EFFORT DE TRAINEE SUR UN SEUIL VERTICAL SOUMIS À UN RESSAUT FORCÉI. Ohtsu, Y. Yasuda and Y. Yamanaka, Vol. 29, No, 1, 1991, pp. 29-47

ISSN:0022-1686    

DOI:10.1080/00221689209498939

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

DRAG ON VERTICAL SILL OF FORCED JUMP EFFORT DE TRAÎNÉE SUR UN SEUIL VERTICAL SOUMIS A UN RESSAUT FORCÉI. Ohtsu, Y. Yasuda and Y. Yamanaka, Vol. 29, No. 1, 1991, pp. 29-47

ISSN:0022-1686    

DOI:10.1080/00221689209498940

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor