| Gravity Water Wave Refractions Using Group Velocity. |
AUG 1970 |
|
| Authors:
Kenneth C. Matson; NAVAL SHIP RESEARCH AND DEVELOPMENT LAB PANAMA CITY FL
|
 | The report documents the incorporation of group velocity into an existing digital computer program which uses phase velocity for calculating gravity water wave rays. Multiperiod rays are used instead of single-period rays. The original gravity water wave refraction program on which this report is based was written in FORTRAN II for the IBM 7094. Development of mathematical expressions that were used to incorporate group velocity into the original computer program ... |
|
| A MODIFIED STATIONARY PRINCIPLE FOR NONLINEAR WAVES. |
APR 1968 |
|
| Authors:
Frederic E. Bisshopp; BROWN UNIV PROVIDENCE R I DIV OF APPLIED MATHEMATICS
|
| Two theorems related to propagation of modulated, nonlinear waves which are governed by stationarity of the integral of a Lagrangian density are derived. They are then used in the analysis of asymptotic approximations which represent nearly uniform wave trains. A relatively detailed treatment of a simple case is followed by a summary of some results which apply to the propagation of capillary-gravity waves in a liquid. (Author) |
|
| NON-LINEAR WAVE EFFECTS ON TIDE GAGES. |
MAY 1967 |
|
| Authors:
Ralph H. Cross; CALIFORNIA UNIV BERKELEY HYDRAULIC ENGINEERING LAB
|
| For tide stations at locations subject to moderate or high waves, the damping device is not linear, since the flow through the orifice is approximately proportional to the square root of the differential head. The purpose of this paper is to investigate the non-linear interaction between this filter and second-order wave theory, specifically estimating the effect of this interaction on the water level inside the stilling well for a variety ... |
|
| COMPLIANT WATER WAVE ABSORBERS - PART 2. |
SEP 1966 |
|
| Authors:
Jerome H. Milgram; MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF NAVAL ARCHITECTURE AND MARINE ENGINEERING
|
| The report which is a continuation of 'Compliant Water Wave Absorbers' (AD-624 508) by the same author, is concerned mainly with theoretical and experimental investigations of a sliding wedge type water wave absorber at the end of a channel. A re-examination of the theory of the stability of linear active wave absorbers is carried out and some errors in symbols and signs appearing in the prior work are corrected. Also, ... |
|
| DETECTION OF PERIODIC DISTURBANCES IN RANDOMLY ROUGH SURFACES. |
27 MAY 1966 |
|
| Authors:
G. Hahn; D. J. Angelakos; CALIFORNIA UNIV BERKELEY ELECTRONICS RESEARCH LAB
|
| A method is presented by which the amplitude and periodicity of a rough water wave may be determined. The method hinges on the fact that electromagnetic waves reflected by a periodic surface are coherent, whereas the signal contributions of the random surface disturbances are incoherent. (Author) |
|
| SOLITARY WAVES IN COMPRESSIBLE, STRATIFIED FLUIDS. |
AUG 1965 |
|
| Authors:
ROBERT R. LONG; Jeffrey B. Morton; JOHNS HOPKINS UNIV BALTIMORE MD DEPT OF MECHANICS
|
| A solitary wave is found in a stratified, compressible fluid in a uniform gravity field. This wave depends for its existence on the compressibility of the medium no matter how small, although the speed of propagation is of the order of an internal gravity wave. The analytical discussion is carried out most fully for small compressibility. Another case, more appropriate for atmospheric problems, is solved by a numerical approach. (Author) ... |
|
| WATER WAVES AT THE SHORELINE. |
15 JUL 1965 |
|
| Authors:
Albion D. Taylor; WISCONSIN UNIV-MADISON DEPT OF MATHEMATICS
|
| The nonlinear equations of two-dimensional wave motion on a shallow beach are used to study motions starting from rest and developing so that the surface elevation, at a fixed distance from the initial shore position, approaches rapidly an approximately simple-harmonic function of time. The Laplace transform is applied to a related problem and is inverted to obtain the solution of the physical problem when the water motion is bore-free. It ... |
|
| SOLITARY WAVES IN RUNNING GASES, |
MAY 1965 |
|
| Authors:
M. C. Shen; NEW YORK UNIV NY COURANT INST OF MATHEMATICAL SCIENCES
|
| Solitary waves in running polytropic gases of finite or infinite height are studied. Explicit expressions for the critical speed and the solution of the solitary waves are obtained by a perturbation scheme applied to the nonlinear equations. It is found that internal waves may also be observed in a running gas, and change of wave type may occur in the medium. The results obtained are expressed in terms of simple ... |
|
| ON INTERNAL GRAVITY WAVES GENERATED BY LOCAL DISTURBANCES. |
FEB 1965 |
|
| Authors:
K. K. Wong; HYDRONAUTICS INC LAUREL MD
|
| The internal waves generated by a time dependent local disturbance in an incompressible continuously stratified fluid are examined. Following the Love theory of wave motion in heterogeneous liquids, the motion is regarded as a small perturbation about the state of hydrostatic equilibrium. For simplicity, the equilibrium density profile is taken to be exponential. It was found that, for a disturbance having a simple harmonic time dependency, the ratio of the ... |
|
| WAVE MEASUREMENTS OFF OXNARD, CALIFORNIA. |
AUG 1964 |
|
| Authors:
Wilber E. Hoffman; NAVAL CIVIL ENGINEERING LAB PORT HUENEME CA
|
| The intent is to furnish a description of a mainly water level (wave) measuring complex in about 18 feet of water behind and in the vicinity of an off-shore breakwater for a small craft harbor. The breakwater serves as a trap for sand which is by-passed periodically around the jetties of a major harbor about one mile downshore. Instruments and methods are discussed for the complex as progessively improved over ... |
|
| THE TABULATION OF MICHELL'S FUNCTION, |
APR 1958 |
|
| Authors:
Garrett Birkhoff; Rohit Parikh; HARVARD UNIV CAMBRIDGE MA
|
|
| Laboratory Study of Short-Crested Wind Waves. |
JUN 1955 |
|
| Authors:
G. C. Ralls Jr.; R. L. Wiegel; CALIFORNIA UNIV BERKELEY WAVE RESEARCH LAB
|
| A laboratory program was undertaken (1) to determine the variation of wavelength, crest length, and wave velocity with fetch, water depth, and wind velocity; (2) to compare measured wave velocity with theory; and (3) to compare the results with those of 2-dimensional laboratory studies. Water depths from 0.5 to 2.5 in., wind speeds from 17 to 30 fps, and fetches from 0.5 to 10 ft were used. The still-water depth ... |
|
| Wave-Velocity Method of Depth Determination by Aerial Photographs. |
07 OCT 1949 |
|
| Authors:
J. W. Johnson; CALIFORNIA UNIV BERKELEY INST OF ENGINEERING RESEARCH
|
| The report presents a procedure for analyzing aerial photos for depth determination by the wave-velocity method. An attempt is made to determine the accuracy of this method by the statistical approach. This latter analysis, however, is not conclusive in view of the fact that profiles by soundings were not available for the same days on which the aerial photos were obtained. Although the statistical analysis indicates that relatively large errors ... |
|
Reports by Keyword(s)
(WATER WAVES
