摘要:

Summary In accordance with experiments on a horizontal rectangular channel supplied steadily from a reservoir through a contraction, the boundary layer on the bottom is taken as laminar and two-dimensional, and the main stream above it is supposed at every cross-section to possess uniform velocity. Simple alternative shapes are assumed for the boundary layer, as in well-known aeronautical theory. With the aid of the continuity and momentum equations, convergent numerical results are obtained; and it is found that, as the boundary-layer thickens downstream, the free surface falls very slightly and the velocity of the main stream increases. The energy equation is also examined and provides a check on the previous work. The calculated boundary-layer thickness is not inconsistent with measurements made in a channel 14 in. wide and 6 ft long.

ISSN:0022-1686    

DOI:10.1080/00221687709499644

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

A “state of the art“ report on the subject of local scour around cylindrical piers is given here. After a description of the scouring process, a critical review of literature on model and field data is presented, and the empirical data are compared with theoretical considerations. The final result is a set of design suggestions together with possibilities for protection against scour.

ISSN:0022-1686    

DOI:10.1080/00221687709499645

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Abstract An analytical solution is obtained for the two-dimensional problem of a narrow horizontal slot in a deeply driven sheet pile which separates a water pool from a dry foundation. It is shown that the presence of even a small gap allows enough How through it to cause considerable wetting on the protected side of the foundation.

ISSN:0022-1686    

DOI:10.1080/00221687709499646

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Summary This paper presents an experimental study on the behaviour of bluff turbulent surface jets discharged into a stagnant ambient for moderate and large source Richardson numbers. Based on fairly extensive observations, the velocity and temperature profiles in the Lateral and vertical directions have been found to be similar. Using the results of an earlier theoretical analysis (by the authors) and the present experimental results, the variation of the velocity, temperature excess and length scales have been correlated with the nondimensional longitudinal distance from the outlet (made dimensionless with the square root of the surface jet at source), and the source Richardson number.

ISSN:0022-1686    

DOI:10.1080/00221687709499647

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Summary This paper presents an experimental study on the erosion of loose beds of sand and polystyrene by circular turbulent wall jets ol" air and water. Characteristics of the scour hole have been observed during its growth and also in the final asymptotic state. These profiles have in general been found to be similar when expressed in dimensionless forms with some dispersion near the ridge which forms at the downstream end of the hole. The length scales (made dimensionless with the jet diameter) and the dimensionless characteristic time have been found to be functions of mainly the densimetric Froude number. Some observations have also been made on the behaviour ol'the jet in the asymptotic erosion state.

ISSN:0022-1686    

DOI:10.1080/00221687709499648

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

BOTTOM TURBULENCEby J. C. J. NIHOUL (ed) Elsevier Scientific Publishing Company, Amsterdam, 1977, XIV+306 pp.

ISSN:0022-1686    

DOI:10.1080/00221687709499649

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221687709499643

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor