Download or read book Surf Zone Wave Kinematics written by Frank Lee Bub and published by . This book was released on 1974 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: The experiment was designed to measure surface profiles and water velocities in the breaker zone and compare the results with present theory. As a secondary objective the accuracy and usefulness of capacitance wave gages and electromagnetic flow meters in the surf environment were evaluated.

Download or read book The Kinematics of Breaking Waves in the Surf Zone written by Alfred James Olsen and published by . This book was released on 1977 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Simultaneous measurements of sea surface elevation and onshore and alongshore water particle velocities were measured at three locations within the surf zone using two capacitance type penetrating wave staffs and three two-component electromagnetic flow meters. The probability density functions, pdf, for the sea surface elevation were always highly positively skewed, whereas the pdf's for the velocities were both negatively and positively skewed. Mean values of the onshore and alongshore components of flow reflected the influence of a rip current frequently observed just south of the instrument locations. Strong harmonics in the spectra of sea surface fluctuations and particle velocities infer nonlinear conditions. Coherence values between waves and onshore flow were high, ranging above 0.9. The coherence between waves and onshore flow was used to separate the turbulence and wave-induced velocity components. Over the range of collapsing to spilling breakers a reasonable value for the ratio of turbulent to wave-induced velocity was determined to be approximately 0.75. Saturation regions were found in the wave and velocity energy-density spectra at higher frequencies as evidenced by -5 and -3 slopes, respectively. (Author).

Download or read book Surf Zone Wave Kinematics written by and published by . This book was released on 1974 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Irregular Wave Kinematics in the Surf Zone written by Nels John Sultan and published by . This book was released on 1995 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Kinematics of Breaking Waves in the Surf Zone written by Victor Sandiford Hultstrand and published by . This book was released on 1977 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements were made of the water level fluctuations and horizontal water particle velocities in breaking waves. The breaking waves were identified and classified. The mean value of the height of breaking to depth of breaking was calculated and found to be 0.86 for a composite of the waves measured; the mean ratio values for collapsing, plunging and spilling were 0.84, 0.87 and 0.90, respectively. Probability distributions were plotted for wave heights and horizontal velocities and qualitatively compared with Rayleigh distributions; the wave distributions fit well but velocity did not. The spectra of wave profile and horizontal velocity were calculated and indicated a narrow banded data set. The coherence values between horizontal water particle velocities and wave profile were generally high, indicating that the horizontal particle velocities measured were highly wave-induced. The phase shift at the peak energy frequency was about 40 deg which suggested the presence of reflected waves. (Author).

Download or read book Kinematics and Directionality of Waves in the Surf Zone written by J. van Heteren and published by . This book was released on 1985 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geometry Kinematics Energetics of Surf Zone Waves Near the Onset of Breaking Using Remote Sensing written by Roxanne J. Carini and published by . This book was released on 2019 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Kinematics of Water Particle Velocities of Breaking Waves Within the Surf Zone written by Edward B. Thornton and published by . This book was released on 1973 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Simultaneous measurements of waves, and vertical and horizontal water particle velocities were made at the breaker-line within the surf zone using a capacitance type penetrating wave staff, a pressure wave gauge, and an electromagnetic current meter. Wave measurements were also made at seaward and shoreward locations. The wave energy-density spectral components were converted to velocity spectral components using linear wave theory. These computed values compared well qualitatively with the measured velocity spectra. Quantitatively, the results showed that linear theory underpredicted wave-induced horizontal velocity spectral components by about 50 percent at the frequency of peak energy. Probability density functions were computed and compared to Gaussian and Gram-Charlier distributions using the chi-square goodness-of-fit test. The Gram-Charlier distribution qualitatively gave the better fit to the data. (Modified author abstract).

Download or read book Kinematics of Surf Zone Breaking Waves written by James Joseph Galvin and published by . This book was released on 1975 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Simultaneous measurements of water surface fluctuations and horizontal water particle velocities in a line perpendicular to the direction of wave approach extending across the surf zone were taken in varying surf conditions at two locations. The spectral velocities calculated using linear theory as a transfer function underestimated measured values by 79-86% at the peak of the spectrum. The coherence values were generally low indicating non-linear and turbulent conditions. Strong harmonics in the spectra of the waves and water particle velocities further suggest a non-linear system. The theoretical phases computed using linear theory did not accurately predict the observed phases. In general breaking waves can be characterized as a strongly non-linear wave phenomenon. Measured frequency distributions were compared with both Gaussian and Gram-Charlier distributions by using the chi-square goodness-of-fit test. Qualitatively, the Gram-Charlier distribution gave the better fit to the flow velocity data.

Download or read book Kinematics of Water Particle Motion Within the Surf Zone written by Rafael Steer and published by . This book was released on 1972 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this research was to make preliminary studies on the kinematics of the water particle motion within the surf zone and within breaking waves. Simultaneous measurements were made of the instantaneous sea surface elevation and of horizontal and vertical particle velocities at different elevations in the same column of water in the surf zone, and of the offshore sea surface elevation. The probability density functions and spectra of the wave and particle velocity measurements were determined.

Download or read book Kinematics of Breaking Waves in the Surf Zone written by and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Observed Kinematics of Waves in the Surf Zone written by Richard K. Constantian and published by . This book was released on 1999 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: The observed kinematics of waves in the surf zone is examined with extensive measurements from the DUCK94 experiment. Field data used in the study were obtained from vertical stacks of bi-directional current meters and a pressure sensor mounted on a rigid frame at 3 locations along a cross-shore transect in depths of 2,4, and 8m. Observed pressure and velocity spectra are compared to transfer functions based on linear finite depth theory and a simple nonlinear model that accounts for harmonic generation in shallow water. At high frequencies, the observed vertical aftenuation of horizontal velocity spectra in 8 and 4m depth is much weaker than predicted by linear theory and generally in good agreement with the nonlinear model predictions. In 2m depth, differences between the linear and nonlinear transfer function are small and both predictions are in reasonable agreement with the observed weak vertical decay. At infragravity frequencies in shallow water depths, observed velocity spectra often show significant vertical decay that is not predicted by either model. Velocity and pressure spectra measured in 4m depth are in good agreement with the nonlinear transfer function. Pressure spectra levels at high frequencies are shown to be significantly reduced by the nonlinear Bernoulli term in the second order pressure field. Analysis of the slopes of the high-frequency tails of the observed velocity spectra shows considerable scatter with a general tendency for spectra to flatten as waves rotate through the surf zone.

Download or read book Observed Kinematics of Waves in the Surf Zone written by and published by . This book was released on 1999 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: The observed kinematics of waves in the surf zone is examined with extensive measurements from the DUCK94 experiment. Field data used in the study were obtained from vertical stacks of bi-directional current meters and a pressure sensor mounted on a rigid frame at 3 locations along a cross-shore transect in depths of 2,4, and 8m. Observed pressure and velocity spectra are compared to transfer functions based on linear finite depth theory and a simple nonlinear model that accounts for harmonic generation in shallow water. At high frequencies, the observed vertical aftenuation of horizontal velocity spectra in 8 and 4m depth is much weaker than predicted by linear theory and generally in good agreement with the nonlinear model predictions. In 2m depth, differences between the linear and nonlinear transfer function are small and both predictions are in reasonable agreement with the observed weak vertical decay. At infragravity frequencies in shallow water depths, observed velocity spectra often show significant vertical decay that is not predicted by either model. Velocity and pressure spectra measured in 4m depth are in good agreement with the nonlinear transfer function. Pressure spectra levels at high frequencies are shown to be significantly reduced by the nonlinear Bernoulli term in the second order pressure field. Analysis of the slopes of the high-frequency tails of the observed velocity spectra shows considerable scatter with a general tendency for spectra to flatten as waves rotate through the surf zone.

Download or read book Kinematics of Water Particle Velocities of Breaking Waves Within the Surf Zone written by and published by . This book was released on 1973 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wave Kinematics and Environmental Forces written by Society for Underwater Technology (SUT) and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt: In determining the response of offshore structures, it is of utmost importance to determine, in the most correct manner, all factors which contribute to the total force acting on these structures. Applying the Morison formula (Morison et. al. , 1950) to calculate forces on offshore slender structures, uncertainties related to the understanding of the wave climate, the hydrodynamic force coefficients and the kinematics of ocean waves represent the most important contributions to the uncertainties in the prediction of the total forces on these structures (Haver and Gudmestad, 1992). Traditional calculation of forces on offshore structures involves the use of regular waves with the following non-linearities inco1porated use of regular wave theories inco1porating higher order terms use of Morison equation having a nonlinear drag term inclusion of the effect of the free surface by integrating all contributions to total forces and moments from the sea floor to the free surface of the waves In order to describe the sea more realistically, the ocean surface is to be described as an irregular sea surface represented by its energy spectrum. The associated decomposition of the sea surface is given as a linear sum of linear waves. The total force is found by integrating the contribution from all components in the wave spectrum to the free surface. The kinematics of each component must therefore be determined.

Download or read book Water Wave Kinematics written by A. Tørum and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 751 pages. Available in PDF, EPUB and Kindle. Book excerpt: Water wave kinematics is a central field of study in ocean and coastal engineering. The wave forces on structures as well as sand erosion both on coastlines and in the ocean are to a large extent governed by the local distribution of velocities and accelerations of the water particles. Our knowledge of waves has generally been derived from measurements of the water surface elevations. The reason for this is that the surface elevations have been of primary interest and fairly cheap and reliable instruments have been developed for such measurements. The water wave kinematics has then been derived from the surface elevation information by various theories. However. the different theories for the calculation of water particle velocities and acceleration have turned out to give significant differences in the calculated responses of structures. In recent years new measurement techniques have made it possible to make accurate velocity measurements. Hence. the editors deemed it to be useful to bring together a group of experts working actively as researchers in the field of water wave kinematics. These experts included theoreticians as well as experimentalists on wave kinematics. It was also deemed useful to include experts on the response of structures to have their views from a structural engineering point of view on what information is really needed on water wave kinematics.

Download or read book Wave Transformation in the Surf Zone written by William R. Dally and published by . This book was released on 1987 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: The random wave model is verified to field data and good agreement is obtained for both statistically representative waves and histograms, without additional calibration. The effect of a collinear current on the breaking process of regular waves is then investigated theoretically and experimentally. A governing equation is proposed and verified to the laboratory data with good results, except for the combination of a short-period wave and a strong opposing current. The effects of long waves such as surf beat (which can be depicted as a slowly varying current and mean water level) on the transformation of random wind-waves is investigated by incorporating the results of the regular wave/current study. If no correlation between the wind-wave group and the surf beat is assumed, only a slight (~ 4%) increase in decay of the root mean square wave height, Hrmg , is observed.