scholarly journals EFFECT OF BEACH SLOPE AND SHOALING ON WAVE ASYMMETRY

1968 ◽  
Vol 1 (11) ◽  
pp. 10 ◽  
Author(s):  
M.D. Adeyemo
Keyword(s):  
Shallow Water ◽  
Quantitative Study ◽  
Experimental Work ◽  
Theoretical Study ◽  
Wave Theory ◽  
Cnoidal Wave ◽  
Quantitative Correlation ◽  
Wave Slope ◽  
Oscillatory Waves ◽  
Good Agreement

This paper is concerned with the quantitative study of the geometrical asymmetry associated with shallow water oscillatory waves in the breaker zone. Three descriptions of wave asymmetry are defined and examined : (l) Wave vertical asymmetry i2^ Wave slope asymmetry and (3) Wave horizontal asymmetry The effects of shoaling, produced by beaches of different slope, on the wave asymmetry are examined. Six beach slopes in the range 1:4 to 1:18 were employed, and a quantitative correlation was found to exist between the wave slope asymmetry, wave horizontal asymmetry and the wave vertical asymmetry. An expression is given for the wave horizontal asymmetry based on the expression for the wave vertical asymmetry from the cnoidal wave theory. The theoretical study of wave slope asymmetry made by Biesel (1) and the results of the experimental work on the wave slope asymmetry in the present work are compared and gave a good agreement*

Effects of Cnoidal Wave-Induced Seepage on Vertical Breakwater Resting on Permeable Elastic Seabed

2014 ◽  
Vol 716-717 ◽  
pp. 284-288
Author(s):  
Jian Kang Yang ◽  
Hua Huang ◽  
Lin Guo ◽  
Jing Rong Lin ◽  
Qing Yong Zhu ◽  
...  
Keyword(s):  
Shallow Water ◽  
Wave Theory ◽  
Cnoidal Wave ◽  
Load Prediction ◽  
Wave Load ◽  
Seepage Pressure ◽  
Theoretical Investigations ◽  
Nonlinearity Effect ◽  
Wave Nonlinearity ◽  
Wave Induced

Theoretical investigations on cnoidal waves interacting with breakwater resting on permeable elastic seabed are presented in this paper. Based on the shallow water reflected wave theory and Biot consolidation theory on wave-induced seepage pressure, the analytical solutions to first order cnoidal wave reflection and wave-induced seepage pressure are obtained by the eigenfunction expansion approach. Numerical results are presented to show the effects of depth of water, breakwater geometry on cnoidal wave-induced seepage uplift force and overturning moment. Compared with Airy wave theory, in certain shallow water conditions, the shallow water wave theory can more effectively illustrate wave nonlinearity effect in wave load prediction.

Effect of Shallow Water on a Mathematical Hull at High Subcritical and Supercritical Speeds

1986 ◽  
Vol 30 (02) ◽  
pp. 85-93
Author(s):  
A. Millward ◽  
M. G. Bevan
Keyword(s):  
Shallow Water ◽  
Wave Theory ◽  
Hull Form ◽  
Towing Tank ◽  
Resistance Peak ◽  
Good Agreement ◽  
Made In

Experiments have been made in a towing tank to measure the resistance of a mathematical hull form in deepwater and in shallow water at high subcritical and supercritical speeds. The data have been compared with calculations using linearized wave theory for the same hull shape. The results have shown fairly good agreement, with the greatest differences occurring near the subcritical resistance peak.

A high-order cnoidal wave theory

1979 ◽  
Vol 94 (1) ◽  
pp. 129-161 ◽  
Author(s):  
J. D. Fenton
Keyword(s):  
Shallow Water ◽  
Wave Height ◽  
Water Depth ◽  
Wave Theory ◽  
High Order ◽  
Stokes Wave ◽  
Cnoidal Wave ◽  
Expansion Parameter ◽  
Wave Solutions ◽  
Fifth Order

A method is outlined by which high-order solutions are obtained for steadily progressing shallow water waves. It is shown that a suitable expansion parameter for these cnoidal wave solutions is the dimensionless wave height divided by the parameter m of the cn functions: this explicitly shows the limitation of the theory to waves in relatively shallow water. The corresponding deep water limitation for Stokes waves is analysed and a modified expansion parameter suggested.Cnoidal wave solutions to fifth order are given so that a steady wave problem with known water depth, wave height and wave period or length may be solved to give expressions for the wave profile and fluid velocities, as well as integral quantities such as wave power and radiation stress. These series solutions seem to exhibit asymptotic behaviour such that there is no gain in including terms beyond fifth order. Results from the present theory are compared with exact numerical results and with experiment. It is concluded that the fifth-order cnoidal theory should be used in preference to fifth-order Stokes wave theory for wavelengths greater than eight times the water depth, when it gives quite accurate results.

scholarly journals SHALLOW WATER WAVES A COMPARISON OF THEORIES AND EXPERIMENTS

1968 ◽  
Vol 1 (11) ◽  
pp. 7 ◽  
Author(s):  
Bernard Le Mahaute ◽  
David Divoky ◽  
Albert Lin
Keyword(s):  
Velocity Field ◽  
Shallow Water ◽  
Water Waves ◽  
Large Amplitude ◽  
Wave Theory ◽  
Engineering Practice ◽  
Cnoidal Wave ◽  
Shallow Water Waves ◽  
Series Of Experiments ◽  
Water Depths

A series of experiments were performed to determine the velocity field and other characteristics of large amplitude shallow water waves. The experimental results were compared with the predictions of a variety of wave theories including those commonly used in engineering practice. While no theory was found exceptionally accurate, the cnoidal wave theory of Keulegan and Patterson appears most adequate for the range of wavelengths and water depths studied.

Cnoidal Wave-Induced Seepage Forces on Large Porous Vertical Circular Cylinder Resting on Porous Elastic Seabed

2014 ◽  
Vol 501-504 ◽  
pp. 2060-2064
Author(s):  
Hua Huang ◽  
Rui Zhi Chen ◽  
Qi Li ◽  
Jie Min Zhang ◽  
Lin Guo
Keyword(s):  
Circular Cylinder ◽  
Shallow Water ◽  
Water Wave ◽  
Wave Theory ◽  
The Body ◽  
Cnoidal Wave ◽  
Wave Load ◽  
Seepage Pressure ◽  
Shallow Water Wave ◽  
Wave Induced

The influence of the porosity of the structure on the shallow water wave-Induced seepage force on the bottom of porous vertical circular cylinder resting on porous elastic seabed has been investigated. Based on the shallow water diffracted wave theory and Biot consolidation theory on wave-induced seepage pressure, the analytical solutions to first order cnoidal wave diffraction by porous vertical circular cylinder and wave-induced seepage pressure are obtained by the eigenfunction expansion approach. Numerical results show that cnoidal wave-induced uplift and moment may have same order of magnitude as the horizontal cnoidal wave force and moment , and the body porosity of the structure may lead to a reduction both in direct cnoidal wave forces and in the cnoidal wave induced seepage moment. Compared with Airy wave theory, in certain shallow water conditions, the shallow water wave theory can more effectively reflect wave nonlinearity effect in wave load prediction.

Explanation of the Influence of Inflow Air Content on the Lift of Cavitating Hydrofoils

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Eduard Amromin
Keyword(s):  
Experimental Data ◽  
Theoretical Study ◽  
Lift Coefficient ◽  
Cavity Surface ◽  
Air Bubbles ◽  
Incoming Flow ◽  
Fluid Density ◽  
Air Content ◽  
Theoretical Results ◽  
Good Agreement

According to several known experiments, an increase of the incoming flow air content can increase the hydrofoil lift coefficient. The presented theoretical study shows that such increase is associated with the decrease of the fluid density at the cavity surface. This decrease is caused by entrainment of air bubbles to the cavity from the surrounding flow. The theoretical results based on such explanation are in a good agreement with the earlier published experimental data for NACA0015.

Cnoidal Wave-Induced Residual Liquefaction in Loosely Deposited Seabed under Coastal Shallow Water

2021 ◽  
Vol 11 (24) ◽  
pp. 11631
Author(s):  
Xiuwei Chai ◽  
Jingyuan Liu ◽  
Yu Zhou
Keyword(s):  
Shallow Water ◽  
Pore Pressure ◽  
Water Environment ◽  
Lateral Spreading ◽  
Stokes Wave ◽  
Cnoidal Wave ◽  
Liquefaction Resistance ◽  
Liquefaction Process ◽  
Wave Induced ◽  
Seabed Soil

This study is aimed at numerically investigating the cnoidal wave-induced dynamics characteristics and the liquefaction process in a loosely deposited seabed floor in a shallow water environment. To achieve this goal, the integrated model FSSI-CAS 2D is taken as the computational platform, and the advanced soil model Pastor–Zienkiewicz Mark III is utilized to describe the complicated mechanical behavior of loose seabed soil. The computational results show that a significant lateral spreading and vertical subsidence could be observed in the loosely deposited seabed floor due to the gradual loss of soil skeleton stiffness caused by the accumulation of pore pressure. The accumulation of pore pressure in the loose seabed is not infinite but limited by the liquefaction resistance line. The seabed soil at some locations could be reached to the full liquefaction state, becoming a type of heavy fluid with great viscosity. Residual liquefaction is a progressive process that is initiated at the upper part of the seabed floor and then enlarges downward. For waves with great height in shallow water, the depth of the liquefaction zone will be greatly overestimated if the Stokes wave theory is used. This study can enhance the understanding of the characteristics of the liquefaction process in a loosely deposited seabed under coastal shallow water and provide a reference for engineering activities.

Furan and Thiophene Analogs of Phenanthrene A Theoretical Study of the Absorption Spectra of Benzodifurans, Benzodithiophenes and Thienobenzofurans

1971 ◽  
Vol 26 (12) ◽  
pp. 1235-1240 ◽  
Author(s):  
L. Klasinc ◽  
J. V. Knop
Keyword(s):  
Absorption Spectra ◽  
Theoretical Study ◽  
Oscillator Strengths ◽  
Electron Transitions ◽  
Good Agreement ◽  
Lcao Mo

The LCAO -MO -SCF -CI method was applied to benzo(1,2-b : 4,3-b′) -difuran and -dithiophene, benzo (2,1-b : 3,4-b′) -difuran and -dithiophene, benzo (1,2-b : 3,4-b′) -difuran and -dithiophene, thieno (2,3-e) benzofuran, thieno (3,2-e) benzofuran, thieno (3,2-g) benzofuran, thieno (2,3-g) benzofuran, benzofuran, benzothiophene and phenanthrene. The calculated π-electron transitions and their oscillator strengths are in good agreement with known absorption spectra. The resemblance of these spectra to the absorption spectra of phenanthrene and phenanthrolines is discussed.

Experimental Verification of Open-loop Control for an Underwater Eel-like Robot

2002 ◽  
Vol 21 (10-11) ◽  
pp. 849-859 ◽  
Author(s):  
Kenneth A. Mcisaac ◽  
James P. Ostrowski
Keyword(s):  
Experimental Work ◽  
Experimental Verification ◽  
Vision System ◽  
Open Loop ◽  
Open Loop Control ◽  
Loop Control ◽  
Position Sensing ◽  
Theoretical Predictions ◽  
Approximate Expressions ◽  
Good Agreement

In this paper, we describe experimental work using an underwater, biomimetic, eel-like robot to verify a simplified dynamic model and open-loop control routines. We compare experimental results to previous analytically derived, but approximate expressions for proposed gaits for forward/backward swimming, circular swimming, sideways swimming and turning in place. We have developed a five-link, underwater eel-like robot, focusing on modularity, reliability and rapid prototyping, to verify our theoretical predictions. Results from open-loop experiments performed with this robot in an aquatic environment using an off-line vision system for position sensing show good agreement with theory.

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