ISSN:0022-1686    

DOI:10.1080/00221688009499547

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Using dimensional analysis, the flow resistance for the case of two-dimensionaluniform flow in the dune regime was expressed in terms of bed-form geometry,sand size and flow condition. Experiments were conducted in a rectangular flumeusing artificial bed forms. The results showed that the flow resistance is affectedby the sand-grain roughness only when the dunes are flat. When dunes aresteep, the flow resistance is due mainly to the form drag and is relativelyconstant. The results also showed that the friction factor obtained by addingthe friction factor due to a plane sand bed and that due to form drag is likelyto be too large if the dunes are steep. It has also been demonstrated that thedune length to depth ratio has a significant effect on the friction factor whenthe dunes are steep. The experimental data were compared with results from otherinvestigators.

ISSN:0022-1686    

DOI:10.1080/00221688009499548

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221688009499549

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

The Birkbeck bedload sampler is described and evaluated under field conditions. A submergedpressure-pillow responds to changes in both stream-stage and bedload sediment accumulating in apit-trap sunk into the stream-bed. Simultaneous changes in both pillow pressure and water-stageare continuously recorded. Subtraction of synchronous values gives a linear response in pressurehead proportional to the changing submerged mass of trapped sediment. Under both controlledlaboratory conditions and field installation, prototypes yield reproducible estimates of bedloadwith a standard error as small as 0.34 kg. The sampler is designed principally for installation insmall streams with flashy flood hydrographs.

ISSN:0022-1686    

DOI:10.1080/00221688009499550

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

A one-dimensional numerical model incorporating the k-ε turbulence model is used to studythe flow in an ice-covered lake dominated by through-flow. The effects of the rotation ofthe earth and vertical heat flux on the dimensionless velocity and eddy viscosity profilesare shown and characteristic length scales are presented.

ISSN:0022-1686    

DOI:10.1080/00221688009499551

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

This paper presents the report of the panel discussion as held at the XVIIIth IAHR Congress at Cagliari, Italy (1979). The topics of the discussion were:

ISSN:0022-1686    

DOI:10.1080/00221688009499552

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221688009499546

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor