摘要:

Nonlinear solutions are given for the aggradation/degradation problem in open channels using the method of perturbation. Linear solutions previously published by the author appear as the first term of the series. Next higher term moves the solution in the right direction and diminishes the discrepancy between the theoretical and experimental results published previously by Soni et al.

ISSN:0022-1686    

DOI:10.1080/00221688709499254

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The hydraulic jump in the triangular channel is analysed using an elementary approach. The results regarding the sequent depth ratio are confirmed by model observations. Furthermore, the length characteristics, the surface profiles and typical velocity distributions are discussed. Finally, these results are compared with the hydraulic jump in the rectangular channel, and interesting conclusions end the paper.

ISSN:0022-1686    

DOI:10.1080/00221688709499255

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The flow induced pipe vibration problems have been studied experimentally. The emphasis of the present paper is placed on the pipe vibration during its sagging process. The bed scour below a pipeline is promoted notably by the pipe vibration. Provided the scour hole below the pipeline is large enough, gravity and the flexibility of the pipeline allow it to sag into the scour hole. Flow velocity is an important factor, but the eroded bed has some restrictive action on the pipe vibration. The gap ratioe0/Dbetween the pipe bottom and the initial plane bed is another important factor. With respect to the pipe vibration the pipe state can be classified as the pre-vibration stage, the lock-in stage and the lock-out stage. For different pipe states the amplitude response tendencies of the pipe are quite different during its sagging process. When the pipe is in the lock-in stage and very close to the bottom of the scour hole, the pipe may vibrate with such an amplitude that it may be damaged due to its impact on the scour hole.

ISSN:0022-1686    

DOI:10.1080/00221688709499256

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

A general formulation for surface deformation generated by a initial localized free surface disturbance is established in double integral form. The initial condition characterizing the localized disturbances can be 1) a movement of the free surface characterized by a velocity distribution, 2) a static departure of the free surface from the still water level, or 3) an impulse on the free surface. Solutions are obtained for a number of cases in which the initial disturbances are mathematically defined, allowing a first integration by Hankel transform. Closed form solutions are obtained in the nondispersive mode, while numerical solutions are obtained in the general cases. It is found that the initial disturbances result in nonoscillatory movements at the origin. Also, the wave motions are little affected by dispersion. The oscillations which are known to exist at a distance are only the results of linear dispersion in deep and intermediate water depth. Also the vertical rebound following the collapse of cavities (in the form of a spike, jet or drop) is explained by discontinuities in the original perturbations.

ISSN:0022-1686    

DOI:10.1080/00221688709499257

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

RIVER ENGINEERINGEdited by M. S. Petersen Prentice-Hall, Englewood Cliffs, N.J. 07632, U.S.A., 580 pages, 1986, hard cover, price US$ 62.05.

ISSN:0022-1686    

DOI:10.1080/00221688709499258

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221688709499253

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor