摘要:

The results of an experimental investigation on the damping action of impermeable, submerged breakwaters of various shapes are presented and discussed. The effectiveness of the breakwater in damping the incident wave energy is measured in terms of coefficient of transmission. The results are plotted in relevant non-dimensional parameters and comparisons are made with wellknown semi-empirical theories and other available experimental results wherever applicable. The results show that the damping action of the waves increases with the height of the barrier, and rectangular-shaped barriers are found to be the best among the various shapes tested.

ISSN:0022-1686    

DOI:10.1080/00221688009499555

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

A laboratory study was undertaken to measure variables responsible for the formation of air-entraining vortices with a slender air core extending from the free surface to the entry of a vertically inverted intake. The measured data indicate unique relations between radial and vertical scale for air-entraining vortices of the above description. From the measured data non-dimensional parameters governing the formation of such vortices were determined. The results, of this approach give universal curves which are independent of the intake geometry and the intake diameter. On this basis the measured data for horizontal intake, given in the previous paper [2], were re-evaluated and the results for both types of intake were compared. It has been found that the effect of the kinematic viscosity and the surface tension on the measured values become negligibly important when nondimensional parameters describing these effects is larger than 3 x 104. A value which is independent of the intake geometry and the intake diameter, but not on the type of intake. The bellmouth entry did not improve critical submergence heads for both types of intake as compared to those obtained for the simple pipe intake, but it, however, did improve entry flow conditions.

ISSN:0022-1686    

DOI:10.1080/00221688009499556

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Parshall flumes are commonly used devices for the measurement of flow rates in open channels such as sewers and irrigation ditches. The operation of these flumes in "nonstandard" situations, such as when faced with distorted upstream velocity profiles or when placed in sloping channel beds, is poorly understood. This paper presents numerical solutions for the flow through Parshall flumes utilizing a three-dimensional, free-surface finite difference code. The effects on flume operation of channel slope, upstream velocity profile distortions, and flume geometry changes are assessed. Experimental results are obtained for a Parshall flume with a 15.2 cm (6 in.) throat width. Experimental and numerical data on important features of the flume flowfield are seen to compare well.

ISSN:0022-1686    

DOI:10.1080/00221688009499557

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Due to the fact that almost every ice research group uses different testing methods, the results of nominally similar tests can vary greatly. This is of course, a hinderance to the Ice Engineering field. In order to improve the quality, comparability and usefulness of the test data resulting from mechanical property investigations, the IAHR Section on Ice Problems considers i t necessary to standardize ice testing methods. Herewith the Working Group of the IAHR Section on Ice Problems proposes i t s recommendations for the "Standardization of Testing Methods for Ice Properties". It should be noted that the suggested recommendations remain open to revision as the development of ice testing methods progresses.

ISSN:0022-1686    

DOI:10.1080/00221688009499558

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

NUMERICAL MODELLING OF MARINE HYDRODYNAMICSby H. G. RAMMING and Z. KOWALIK Elsevier Scientific Publishing Company, P.O. Box 330, Amsterdam, The Netherlands and in New York. 368 pp, 97 figures. Price US$ 63.50, Dfl. 130.–. Handcoverclothbound, 16 cm x 24 cm offset. ISBN 0-444-41849-0.

ISSN:0022-1686    

DOI:10.1080/00221688009499559

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

In a previous paper, an entirely different method was proposed for the study of the problems investigated by Messrs. KAZEMIPOUR and APELT. The note hereafter exposes shortly the similarities and the differences between the two methods.

ISSN:0022-1686    

DOI:10.1080/00221688009499560

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221688009499554

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor