摘要:

Hydraulic engineers conduct experiments based on which empirical laws are developed for the physical processes involved. However, during the design and analysis stage, the step often falls short of recognizing the inherent uncertainty associated with the developed empirical laws. This paper discusses the presence of various uncertainties in the empirical equations derived from hydraulic experiments and illustrates how to incorporate such uncertainties in probabilistic design of hydraulic structures.

ISSN:0022-1686    

DOI:10.1080/00221689409498736

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Undular bores, sometimes called Favre Waves, occur in channels for navigation, irrigation, power production. They are investigated for rectangular and trapezoidal cross-sections by comparing analytical and numerical models with experimental data. Undular bores in trapezoidal channels are shown to differ significantly from those in rectangular channels; waves are higher above the embankments than in the center. An extension of the Boussinesq wave theory has been used succesfully to describe these phenomena.

ISSN:0022-1686    

DOI:10.1080/00221689409498737

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

New, detailed investigations of the formation of surge waves in open channels are presented in this paper.

ISSN:0022-1686    

DOI:10.1080/00221689409498738

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

An eigenfunction expansion method is used to analyze the generation and propagation of linear water waves down a wave flume consisting of a wavemaker, an abrupt expansion, (possibly) a finite width vertical porous breakwater spanning the channel, and a fully absorbing ending wall.

ISSN:0022-1686    

DOI:10.1080/00221689409498739

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

HYDROSYSTEMES FLUVIAUX (FLUVIAL HYDROSYSTEMS)by C. Amoros and G. E. Petts Collection d'ccologie 24, Masson, Paris, France, S.B. 320 pp., F.FR. 290,-, ISBN 2-225-84246-9.

ISSN:0022-1686    

DOI:10.1080/00221689409498740

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The Ploeg and Funke TYPE E double-actuated wavemaker has been calibrated at the CEPYC-CEDEX Laboratory in Madrid, Spain. TYPE E double-actuated wavemakers are capable of operating as piston-only, hinged-only, or simultaneously as both piston and hinged wavemakers. An eigenfunction expansion for the fluid motion generated by a generic planar wavemaker of variable-draft is used to describe the motion of double-actuated wavemakers. This generic solution appears to be more robust and easier to apply in numerical codes than the ones that require the amplitude of the wavemaker stroke be specified at the still-water-level and that require the draft of the hinge to be forced to minus infinity in order to recover a piston wavemaker. The dimensionless transfer functions for the ratio of the wavemaker stroke to the wave amplitude are derived by equating the total average power generated by both actuators to the energy flux in the propagating wave. The solution is not unique because both the ratio of the amplitude of the piston actuator to the amplitude of the hinge actuator and the relative phase angle between the motion of the two actuators are arbitrary. Experimental verifications of the theory are given for each actuator operating independently as well as for three ratios of the piston amplitude to hinge amplitude when the relative phase angle is zero. These calibrations indicate that TYPE E double-actuated wavemakers are perhaps the optimum wavemakers for simulating double-peaked spectra such as the six parameter Ochi-Hubble spectra where the hinge actuator is optimum for generating the higher frequency components.

ISSN:0022-1686    

DOI:10.1080/00221689409498741

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A finite-differnece scheme is presented to calculate for nonlinear conditions the hydrodynamic pressures acting on the rigid dam faces during earthquakes. The two dimensional geometry of the dam face may be non-vertical and the reservoir bottom non-horizontal. Nonlinearity of free surface flow and convective acceleration are included in the analysis. The numerical results of the onset hydrodynamic pressures acting on a constant-slope dam face and reservoir bottom due to a constant ground acceleration compare very well with those of the exact solutions. Small variations reflect the minor difference of the reservoir geometry between those two cases. Numerical results are for dam faces and compared with experimental and alternative numerical solutions. The rises of the water surface and the increases of hydrodynamic pressure on dam faces are also reported.

ISSN:0022-1686    

DOI:10.1080/00221689409498742

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

USE OF MODELS FOR RIVER PROBLEMS.Studies and reports in Hydrology 51 by M. de Vries UNESCO, Paris, 1993.

ISSN:0022-1686    

DOI:10.1080/00221689409498743

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A numerical model to compute the free-surface flow by solving the depth-averaged, two-dimensional, unsteady flow equations is presented. The turbulence stresses are closed by using a depth-averagedmodel. However, viscous stresses and momentum dispersion stresses are neglected. The governing equations are first transformed into a general curvilinear coordinate system and then solved by the Beam and Warming Alternating Direction Implicit (ADI) scheme. To verify the model and illustrate its applications in hydraulic engineering, it is used to analyze (i) the developed uniform flow in a straight rectangular channel, (ii) hydraulic jump in a diverging channel, (iii) supercritical flow in a diverging channel, and (iv) circular hydraulic jump. The computed results are compared with the available measured data. The comparison of results with and without effective stresses shows that in many cases the effective stresses do not significantly affect the solution. However, it was observed that the computation of supercritical flow in a diverging channel and the simulation of radial hydraulic jump was improved when the depth-averagedmodel was applied.

ISSN:0022-1686    

DOI:10.1080/00221689409498744

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Stepped chutes have become recently a popular method for discharging flood waters. The steps increase significantly the rate of energy dissipation taking place on the spillway face and reduce the size of the required downstream energy dissipation basin. This paper reviews the hydraulic characteristics of skimming flows. The onset of skimming flows is discussed. New results are presented to estimate the flow resistance along stepped chutes. The study indicates some major difference between the flow patterns on steep and flat stepped chutes. An analogy with flow over large roughness is developed. Then the calculations of the start of air entrainment are detailed. The results indicate that free surface aeration occurs much more upstream than on smooth spillways. The effects of flow aeration are later discussed.

ISSN:0022-1686    

DOI:10.1080/00221689409498745

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor