摘要:

The stability of two-layer stratified flow is analyzed utilizing as a stability criterion the condition that the celerity of kinematic internal waves dominated by friction and/or exchange of mass, be less than the celerity of intertia-dominated internal waves. This criterion for stability on scales large with respect to the depth is related to the well-known Vedernikov criterion for open-channel flow. The influence of bottom and interface friction on stability is examined for underflow. overflow, exchange flow and the case of coflowing layers. Taking into account non-uniformity of the velocity profiles is shown to increase the stability. Non-uniformity of the density profiles produces the opposite effect. The influence of small-scale mixing (entrainment) on the stability of underflow is also analyzed.

ISSN:0022-1686    

DOI:10.1080/00221688309499433

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

This paper presents the results of an exploratory study on the development of clear-water scour near a simple groyne-like structure. The growth of the maximum depth of scour with time has been found to be similar. Further, the characteristics of the scour hole in the end state have also been found to be similar. Some simple correlations have also been developed for predicting the maximum depth of clear-water scour in the end state for a narrow range of the relative width parameter.

ISSN:0022-1686    

DOI:10.1080/00221688309499434

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Experiments concerning the drag force on circular cylinders placed in an open channel with a smooth boundary are reported. The studies were carried out under subcritical flow conditions using 31 mm diameter cylinders placed at various blockage ratios. A theoretical analysis has been carried out to obtain a relationship between the three interrelated quantities - energy loss, afflux and drag force. The experimental data on drag collected during this study as well as those collected earlier have been analysed to obtain an empirical relationship for the drag coefficient of circular cylinders placed in an open channel.

ISSN:0022-1686    

DOI:10.1080/00221688309499435

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

An analytical study is made of pressures on a spillway apron downstream from a partly raised gate, and the results compared with experiment.

ISSN:0022-1686    

DOI:10.1080/00221688309499436

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The above discussion of the ripple-dune problem in unidirectional flow is aimed at raising questions and challenging researchers not to accept the partial answers, known so far, as the truth. As a contribution, a hypothesis for the development of bed features is put forward which offers a chance to describe the bed features in concurrent deterministic and random forms.

ISSN:0022-1686    

DOI:10.1080/00221688309499437

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221688309499432

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor