ISSN:0022-1686    

DOI:10.1080/00221689009499080

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221689009499081

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221689009499082

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Preliminary results from the Flood Channel Facility sponsored by the British Science and Engineering Research Council and Hydraulics Research Ltd. are presented. The Facility takes the form of a large compound channel and the first series of experiments have been analysed to assess flow resistance characteristics of simple and compound channels having smooth boundaries. The effects of momentum transfer from main channel to flood plains on the capacity of the compound and main channel sections have been demonstrated. Flow resistance relationships for the compound section, main channel and flood plains have been presented in terms of Manning's and Darcy-Weisbach resistance coefficients, and compared with simple channel shapes. This has emphasised the complexity of compound channel flow resistance, while also pointing out the likely errors involved in applying simple channel methods of analysis and design to rivers and channels of compound geometry.

ISSN:0022-1686    

DOI:10.1080/00221689009499083

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Some experimental results are presented from the SERC Flood Channel Facility at Hydraulics Research, Wallingford, for discharge and boundary shear stress distribution in symmetrical compound channel/flood plain sections of varying flood plain width and roughness. These are used to assess the performance of several standard discharge calculation methods, which assume different locations of the interface between main channel and flood plain sub-areas. It is shown that these methods can produce large errors in total and, more particularly, component discharges, which increase significantly with flood plain width and roughness. A modified form of the above methods is discussed, which makes a more realistic allowance for interaction at the main channel/flood plain interface. It achieves this by incorporating the 0-indices, first suggested by Radojkovic to characterise momentum transfer between adjacent sub-areas, into the calculation. This modified method is shown to be considerably more accurate than the standard methods in calculating total and component discharges. A tentative regression equation is presented for calculating 0-indices from easily identifiable cross-section characteristics.

ISSN:0022-1686    

DOI:10.1080/00221689009499084

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The paper describes some turbulence measurements carried out in the SERC Flood Channel Facility at Hydraulics Research Ltd., Wallingford, U.K. The facility represents a large scale model of a river system with floodplains, and is designed to produce fully developed boundary layer flows with transverse shear. This article presents some of the open channel flow data, including measurements of the primary velocity,Ū/u*, the distribution of turbulent intensities,u1/u*,v1/u*, andw1/u*, the kinetic energy,k/u2*, and the Reynolds stresses τzxand τyxin the region of strong lateral shear induced by transverse variation in depth. Attention is focussed on the non linear nature of the Reynolds stresses in the shear layer, flow structures and the lateral variations in eddy viscosity and local friction factor.

ISSN:0022-1686    

DOI:10.1080/00221689009499085

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

This article describes experiments carried out on a skewed compound channel in the SERC Flood Channel Facility operated at Hydraulics Research Ltd, Wallingford, England. The project is one of a co-ordinated group of four being run simultaneously by U.K. University research groups into the hydraulics of overbank river flow. The other three projects in the group deal with parallel flow in a prismatic compound channel but this one examines the interactive cross-flows that occur between floodplain and main channel when the two are not parallel. The project was designed to prepare the way for a later examination of overbank flow in meandering channels.

ISSN:0022-1686    

DOI:10.1080/00221689009499086

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The flow regimes for three-layer unidirectional flow over a bottom hump are classified using a graduallyvarying flow model. For the particular case of three-layer flow with fixed flowrates in each layer, there are ten possible flow regimes, each representing a different set of locations for the hydraulic controls. Unidirectional three-layer flow has one control for each of the three wave speeds: first- and second-mode internal wave and free-surface wave. A solution for three-layer flow through a contraction is also presented. Transitions between flow regimes are determined by comparing local maxima and minima in the variation of lower layer energy with layer thickness at key cross-sections. Experimental data show that the graduallyvarying (low model is able to successfully predict the actual interface and free-surface profiles except when the main control at the hump is an approach control. Solutions for three-layer flow at a first-mode crest control are used to illustrate the expected behaviour of multi-layered or continuously-stratified flow at a first-mode control.

ISSN:0022-1686    

DOI:10.1080/00221689009499087

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Drop structures involve, among other phenomena, the wave type flow. Using extensive observational data, correlations between the basic inflow parameters and quantities of interest are presented. The latter involve the sequent depths, the coordinates of the wave maximum, the plunging point, the lengths of both the surface roller and the jump, and the longitudinal extension of the bottom separation zone. All quantities are presented in terms of inflow parameters, such that immediate application to design is ensured.

ISSN:0022-1686    

DOI:10.1080/00221689009499088

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221689009499089

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor