摘要:

The most powerful use of the SSARR model is in its flexibility which permits the user to model hydrologically any watershed. However, hydrologie experience and familiarity with the program are needed for the successful use of this model. The great flexibility of the model comes from the watershed parameters (sixteen) introduced in the model. The present studies give a basis understanding of these parameters and their effects on the streamflow computation. An attempt has been made to quantify these effects in giving in per cent the variations of discharge, runoff volume, etc. in relation with the variations of each parameter. Results of this studies could be used by anyone who applies the SSARR program to the model any particular watershed.

ISSN:0022-1686    

DOI:10.1080/00221687809499629

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

The erosion of visco-plastic cohesive soils under the action of a turbulent fluid flow is studied. The equations describing a sediment bed are discussed. To solve them, the density distribution in the bed must be known at some initial time. Experimental field studies and results from the ultracentrifuge provide a clear picture of the density distribution in sediment layers.

ISSN:0022-1686    

DOI:10.1080/00221687809499630

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

In this paper a simple method has been developed for solution of multigate systems often used in hydraulic engineering. While the problem cannot be rigorously analysed, the solution is based on a simplified theoretical approach of divided flow and experimental evidence obtained from laboratory study. In order to dispense with laborious iterative computations, a working diagram has been developed which enables speedy and simple solution of engineering problems. A few numerical examples were worked out and checked in the model, with remarkably good agreement.

ISSN:0022-1686    

DOI:10.1080/00221687809499631

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Particularly in its empiric part this report is based on model tests carried out by universities and manufacturers of hydraulic turbo-machines, who are members of Working Group 5 (WG 5) of the "Section on Hydraulic Machinery, Equipment and Cavitation" of the IAHR. The scale-up behaviour is dealt with on the basis of separate analyses of losses, whereby an important section refers to the influence of surface machining and depth of roughnessRtof separate machine components (full-size plant). Corresponding calculations result in figures which express the modifications in efficiency Δη(ri)due to the accepted roughness, size of the machine and specific energyYof the head. The figures forRtrefer to data supplied by leading manufacturers of hydraulic equipment for power stations. Apart from a differentiated insight into the scaling-up process, the report also provides indications and guide-lines for answering the question as to the economically acceptable amount of machining for which the losses caused by roughness remain within reasonable, predetermined limits. This corresponds with the ende avour to realize optimum machining of machine components in contact with the flow, namely in relation to the type of machine, its size (D) and specific energy (Y). The final result is a global efficiency scale-up Δη(tot), which takes into account, apart from the influence of the Reynolds number, also the increase in losses due to the roughness of the surfaces of the full-size machine. The method of calculation is explained with the aid of tables, taking as an example a Francis turbine (nq^≈ 45), whilst diagrams illustrate the influence of D, Y and Rt on Δη(ri)and Δη(tot).

ISSN:0022-1686    

DOI:10.1080/00221687809499632

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

DISCHARGE MEASUREMENT STRUCTURESby M. G. Boss (editor), International Institute for Land Reclamation and Improvement, P.O. Box 45, Wageningen, The Netherlands. Price DA 30,–.

ISSN:0022-1686    

DOI:10.1080/00221687809499633

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221687809499634

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221687809499628

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor