摘要:

This literature review presents the state-of-the-art concerning sediment sewer transport modelling. After a description of solid particles found in domestic sewage and in storm water, the different steps taken into account in models are described: build-up over the catchment, washoff by rainfall, transfer through gully pots, transport, deposition and erosion in sewer pipes. For each step, several modelling approaches are presented with their basic equations. The paper ends with a short presentation of some models, and with some remarks about the comparison between models and field experimental data.

ISSN:0022-1686    

DOI:10.1080/00221689309498869

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A numerical model for an idealized circular tank with no baffle is used to investigate the relative importance of inlet solids concentration and inlet flow on the removal of solids field. Effluent concentration is very sensitive to the velocities in the withdrawal zone. The densimetric Froude number relates hydraulic and solids loading. It was found that the upward velocities in the withdrawal zone increase with decreasing densimetric Froude number for a constant discharge. Under constant solids loading there is an optimum densimetric Froude number for minimum effluent concentration. The performance of the clarifier is a function of the densimetric Froude number and the return activated sludge ratio. For the clarifier considered here, the minimum effluent concentration for a constant solids loading, occurred at a densimetric Froude number of about 0.5. The Reynolds number, when in the turbulent regime, did not significantly affect the tank hydrodynamics. The predicted solids distribution was in good agreement with the field data. The flow pattern was verified by comparison with thermal density current in a scale model.

ISSN:0022-1686    

DOI:10.1080/00221689309498870

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The transition from supercritical to subcritical flow observed in a laboratory flume is characterized in the presence of a single large bed element (LBE). The present description is both qualitative and quantitative. Three types of jets are identified as a result of water striking the LBE. Transitional tumbling flow around the LBE follows one of three possible surface profiles:

ISSN:0022-1686    

DOI:10.1080/00221689309498871

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The dispersion function for the movement of a cloud of tagged sediments with identical hydraulic characteristics under the action of a steady uniform flow may be expressed in terms of some pertinent correlation statistics that can be obtained from the results of single radio-active tracer experiments. These statistics were derived in terms of the auto and cross serial correlations of step lengths and rest durations of single particle motions. The long term dispersion function was examined taking into account the auto and cross serial correlations of the step lengths and rest durations. Comparisons were also made for the case with independent step lengths, independent rest durations and with the step lengths independent of the rest durations.

ISSN:0022-1686    

DOI:10.1080/00221689309498872

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

REVIEW “SLURRY TRANSPORT USING CENTRIFUGAL PUMPS” Elsevier Science PublishersLtd., Crown House, Linton Rd., Barking, Essex, IG11 8JU U.K., 1992, 355 pp. ISBN 1-85166-745-8 HB £ 52,-

ISSN:0022-1686    

DOI:10.1080/00221689309498873

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Recent research has shown that conventional methods for the hydraulic design of two-stage channels are incorrect as they fail to allow for the loss in conveyance arising from the interaction between the main channel and flood plains. Recent research at large scale has been reviewed and interpretted in the context of the need for practical design procedures. Flow may lie in one of several regions of performance depending largely on the relative depths of flow on the flood plains and in the main channel, and a suite of functions has been derived for assessing overall conveyance, allowing also for a wide range of geometries and different roughness between flood plain and main channel. The new information has wide implications for openchannel hydraulics, river engineering and flood management.

ISSN:0022-1686    

DOI:10.1080/00221689309498874

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

GLOSSARY OF HYDROLOGY, 1992 by Shuh-shiaw Lo Printed and bound by Sheng Te Printers Ltd, Taipei, Taiwan, China. Distributed by Water Resources Publications, P.O. Box 2841, Littleton, Colorado 80161, USA. ISBN Number 0-918334-74-8

ISSN:0022-1686    

DOI:10.1080/00221689309498875

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A weighting function model of transient turbulent pipe friction at moderate Reynolds Numbers is developed in a similar manner to Zielke's equivalent expression for laminar flow (1968). It is shown that a family of weighting function curves exists and that Zielke's curve is an upper bound asymptote that is valid for low Reynolds numbers, not only for laminar flow.

ISSN:0022-1686    

DOI:10.1080/00221689309498876

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The purpose of this paper is to show how small, submerged vortex generators can be used for adjusting the flow pattern in open-channel flows. The vortex generators are vanes or foils installed on the channel bottom in certain configurations. Their height is typically 0.2 to 0.5 times flow depth, their length is about 2 to 3 times their height, and their angle with the flow between 15° and 30°. Described are the adjustments of the flow field effected by a single vane, a vane pair, and several vanes arranged in arrays along one side of the channel. Experimental data are used to develop formulas for calculating the flow adjustments across a channel having vane arrays along one side.

ISSN:0022-1686    

DOI:10.1080/00221689309498877

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Dynamic coupling between a steady state boundary layer flow over a fluid-saturated porous bed with the Darcy flow occurring in the bed is analyzed by employing an appropriate boundary condition to account for the tangential slip at the permeable interface separating the two flows. Numerical solutions of the resulting nonlinear boundary value problem, obtained by the shooting method, are presented for different values of the permeability parameter A" of the bed and the characteristic Reynolds number R of the potential flow impinging on the bed. It is shown that under experimental conditions for whichK2R<1, there exists a sublayer attached to the bed, in which the normal velocity of the fluid is directed upwards, that is, opposite to that of the potential flow.

ISSN:0022-1686    

DOI:10.1080/00221689309498878

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor