摘要:

A method for analysing supercritical flow in a channel fitted with a side weir has been developed and tested against experimental data. Results of the experimental programme have established the conditions under which supercritical flow occurs along a side weir, and showed that in cases where the flow upstream of the weir is subcritical the draw-down to supercritical flow produces sufficient curvature of the streamlines to affect the vertical pressure distribution. Modification of the differential equation to allow for curvature effects has significantly improved the accuracy of computation of depths and discharges. The depth at the upstream end of the weir is shown to be a function of the upstream critical depth, the weir crest height and the slope of the channel, and the rate of change of surface curvature along the upstream portion of the weir is found to depend on the upstream critical depth. Apart from these relationships little use is made of empirical formulae in analysis, so that the method may be applied to any side weir where supercritical flow occurs.

ISSN:0022-1686    

DOI:10.1080/00221688309499455

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Many of the materials used in pipe manufacturing, particularly plastics, prove to be visco-elastic. As the propagation velocity of pressure waves primarily depends on the fluid bulk modulus and the elasticity of the pipe wall the above material property is of great influence in unsteady pipe flow. Furthermore the damping of the waves is caused by frictional losses in the flow as well as by the non-elasticity of the pipe material. The applicability of the method of characteristics - although being a powerful tool for the analysis of a wide range of problems - is limited in the sense that purely elastic strain behaviour has to be assumed. In order to take into account the special properties of visco-elastic pipes two methods for the computation of various types of unsteady flow were developed. By means of the impedance method it is possible to calculate a stable periodic pipe flow and, in particular, the resonance behaviour of conduits. The impulse-responsemethod based on the theory of linear systems is used for the computation of non-periodic flow, for example waterhammer analysis.

ISSN:0022-1686    

DOI:10.1080/00221688309499456

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221688309499463

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Diffusion equation is used to describe degradation of channel beds below dams and in rectangular channels whose base level is abruptly lowered. Analytical solutions are presented for computations at large and small values of time.

ISSN:0022-1686    

DOI:10.1080/00221688309499458

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

A method for calibrating the hot-film anemometer is presented. The turbulent boundary layer in a recirculating water tunnel was investigated. Both mean velocity and turbulence intensivity were measured. The results are compared with the theory and the agreement is satisfactory.

ISSN:0022-1686    

DOI:10.1080/00221688309499459

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221688309499460

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221688309499461

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221688309499462

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221688309499464

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221688309499465

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor