摘要:

The roughness of movable beds, which are deformed by the formation of sand dunes, is not constant since bed topography is dependent on flow characteristics. The relationship between the energy dissipated by the flow and its average velocity deviates, therefore, from the quadratic form generally used to express hydraulically rough flow; it is nevertheless possible to describe the general form of this relationship and then determine its exact terms using the Einstein and Engelund methods.

ISSN:0022-1686    

DOI:10.1080/00221687909499596

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

A constant flow down a circular bend in a rotating open channel of rectangular cross section is considered. By using the eddy viscosity concept combined with a finite slip velocity at the bed, simple analytical solutions of the problem are obtained. They show a helical motion induced by the combined effects of channel curvature and Coriolis force. For values of the inverse Rossby number close to zero we have the well known secondary flow away from the centre of curvature near the surface and towards it near the bottom. As the inverse Rossby number increases the secondary flow is strengthened or weakened depending on the relative direction of rotation of the basic flow. The basic flow is also shown to be strongly influenced by the inverse Rossby number.

ISSN:0022-1686    

DOI:10.1080/00221687909499597

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

An implicit finite difference method is described for solving the equations of motion of a two-layer stably stratified fluid in one dimension. The computational scheme is applicable to smoothly varying subcritical flows and is formulated in terms of layer transport and thickness in order to optimize computer efficiency. Stability analyses of the method show that waves forming at the grid scale are undamped and two approaches for controlling this wave growth are discussed. Comparisons with experimental data show the method to be accurate provided that the natural long wave motions are well resolved and the grid scale waves are filtered from the solutions. Numerical tests indicate a minimum of 20 points per wave length or period can be considered as a lower limit for resolution.

ISSN:0022-1686    

DOI:10.1080/00221687909499598

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

An analysis of the selective withdrawal features of a two-dimensional skimmer wall is developed based on the concept of a double critical flow section in the two-layered stratified fluid system. The theory predicts the withdrawal ratio as a function of two governing parameters, a densimetric Froude number and a layer depth ratio. The skimmer wall design condition of incipient withdrawal as derived by HARLEMAN and ELDER (1965) is included as a special case. Good qualitative agreement with available experimental data is found. An “effectiveness” diagram displaying the fully effective, partially effective and non-effective regimes of skimmer wall operation is developed.

ISSN:0022-1686    

DOI:10.1080/00221687909499599

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

An experimental study is made of the selective withdrawal characteristics of a round horizontal axis pipe intake located in a vertical wall. The ambient fluid system has a two-layer stratification with a diffuse interface. The results for incipient withdrawal indicate considerably lower critical Froude numbers than that obtained by earlier studies by CRAYA (1949) and GARIEL (1949). Geometry effects due to the intake diameter and the pycnocline thickness appear to cause this discrepancy. The supercritical withdrawal ratio from both fluid layers exhibits a unique dependence on the densimetric Froude number normalized by its critical value.

ISSN:0022-1686    

DOI:10.1080/00221687909499600

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

MODELLING HYDROELASTIC VIBRATIONSby OTTO HASZPRA, Published by Akadémiai Kiadó, Alkotmany u. 21, Budapest V, Hungary

ISSN:0022-1686    

DOI:10.1080/00221687909499601

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221687909499602

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221687909499603

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221687909499604

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221687909499605

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor