摘要:

Most of the methods used for the computation of uniform flow in channels with flood plains are based on a separate determination of the flow in the main channel and the flood plains. Here a single channel method is proposed which allow the direct determination for the stage-discharge relation in a channel with flood plain. The approach is empirical and gives satisfactory results.

ISSN:0022-1686    

DOI:10.1080/00221688709499296

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Water velocities in the centimeter or millimeter per second range are measurable by only a few instruments. Experimental laboratory studies frequently require such measurements. An inexpensive optical hydrogen bubble tracing device is described for velocity measurements in the range 0.5 to 8 cm/s. Modification to a thymol blue (pH) tracer method extends its applicability to the range 0.1 to 1.0 cm/s. Design and operational characteristics of the hydrogen bubble/thymol blue current meter are described. Analysis of low Reynolds number flow around a cylinder is used to explain meter calibration characteristics.

ISSN:0022-1686    

DOI:10.1080/00221688709499297

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Based on the results of a first study, the present investigation considers discharge characteristics of a local, discontinuous contraction in a rectangular channel for submerged flow conditions. The theoretical approach analyses the separation zone as well as the local head-loss along the contraction by accounting for the contraction ratio, the inlet angle and the relative contraction length. General solutions are obtained by a matching procedure, and design relations are established. The results are compared with observations, and a good agreement is found.

ISSN:0022-1686    

DOI:10.1080/00221688709499298

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221688709499299

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Singular perturbation techniques are used to obtain an approximate solution of the flood routing problem. The first-order outer solution is given by the kinematic-wave approximation. Singularities in this outer solution then lead to two inner solutions: one that follows a kinematic shock as it moves downstream and one either at the downstream boundary in subcritical flow or at the upstream boundary in supercritical flow. Solutions calculated in each of these subregions allow conclusions to be drawn about the relative importance of various terms in the momentum equation. The inner and outer solutions are combined to obtain composite solutions for flow depths and flow rates, and a numerical example is worked.

ISSN:0022-1686    

DOI:10.1080/00221688709499300

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

In aU-shaped pipe, are studied the density effects following a change in the inlet temperature. When the flow rate is small and the temperature difference high, thermal stratifications appear. The two-dimensional numerical modelling uses finite difference methods with a curvilinear grid, andk-εa models for turbulence. The computation allows to predict with good accuracy the phenomena which are observed from experiment.

ISSN:0022-1686    

DOI:10.1080/00221688709499301

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221688709499295

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor