scholarly journals Graded resonator arrays for spatial frequency separation and amplification of water waves

2018 ◽  
Vol 854 ◽  
Author(s):  
Luke G. Bennetts ◽  
Malte A. Peter ◽  
Richard V. Craster
Keyword(s):  
Spatial Frequency ◽  
Incident Wave ◽  
Water Waves ◽  
Matrix Analysis ◽  
Frequency Separation ◽  
Linear Potential ◽  
Slowing Down ◽  
Line Array ◽  
Plane Incident Wave ◽  
Transfer Matrix Analysis

A structure capable of substantially amplifying water waves over a broad range of frequencies at selected locations is proposed. The structure consists of a small number of C-shaped cylinders in a line array, with the cylinder properties graded along the array. Using linear potential-flow theory, it is shown that the energy carried by a plane incident wave is amplified within specified cylinders for wavelengths comparable to the array length and for a range of incident directions. Transfer-matrix analysis is used to attribute the large amplifications to excitation of local Rayleigh–Bloch waves and gradual slowing down of their group velocity along the array.

Radiation and scattering of water waves by rigid bodies

1971 ◽  
Vol 46 (1) ◽  
pp. 151-164 ◽  
Author(s):  
J. L. Black ◽  
C. C. Mei ◽  
M. C. G. Bray
Keyword(s):  
Surface Waves ◽  
Incident Wave ◽  
Water Waves ◽  
Variational Formulation ◽  
Rigid Bodies ◽  
Small Oscillation ◽  
Circular Cylinders ◽  
Wave Forces ◽  
Far Field ◽  
Plane Incident Wave

Schwinger's variational formulation is applied to the radiation of surface waves due to small oscillation of bodies. By means of Haskind's theorem the wave forces on a stationary body due to a plane incident wave are found using only far-field properties. Results for horizontal rectangular and vertical circular cylinders are presented.

Applicability and limitations of highly non-linear potential flow solvers in the context of water waves

2017 ◽  
Vol 142 ◽  
pp. 233-244 ◽  
Author(s):  
Guillaume Ducrozet ◽  
Félicien Bonnefoy ◽  
Yves Perignon
Keyword(s):  
Potential Flow ◽  
Water Waves ◽  
Linear Potential ◽  
Non Linear

scholarly journals MACH-REFLECTION AS A DIFFRACTION PROBLEM

1976 ◽  
Vol 1 (15) ◽  
pp. 45 ◽  
Author(s):  
Udo Berger ◽  
Soren Kohlhase
Keyword(s):  
Wave Height ◽  
Incident Wave ◽  
Water Waves ◽  
Gas Dynamics ◽  
Mach Reflection ◽  
Diffraction Problem ◽  
Vertical Wall ◽  
Oblique Wave ◽  
Wave Heights ◽  
The Waves

As under oblique wave approach water waves are reflected by a vertical wall, a wave branching effect (stem) develops normal to the reflecting wall. The waves progressing along the wall will steep up. The wave heights increase up to more than twice the incident wave height. The £jtudy has pointed out that this effect, which is usually called MACH-REFLECTION, is not to be taken as an analogy to gas dynamics, but should be interpreted as a diffraction problem.

scholarly journals SURF SIMILARITY

1974 ◽  
Vol 1 (14) ◽  
pp. 26 ◽  
Author(s):  
J.A. Battjes
Keyword(s):  
Phase Difference ◽  
Incident Wave ◽  
Water Waves ◽  
Slope Angle ◽  
Wave Steepness ◽  
Similarity Parameter ◽  
General Terms ◽  
Depth Ratio ◽  
Run Up ◽  
Set Up

This paper deals with the following aspects of periodic water waves breaking on a plane slope breaking criterion, breaker type, phase difference across the surfzone, breaker height-to-depth ratio, run-up and set-up, and reflection. It is shown that these are approximately governed by a single similarity parameter only, embodying both the effects of slope angle and incident wave steepness. Various physical interpretations of this similarity parameter are given, while its role is discussed m general terms from the viewpoint of model prototype similarity.

A Study on Predictions of Fully Nonlinear Motion Aircushion Type Floating Structures Using 2D MPS Method

2008 ◽  
Author(s):  
Mitsuhiro Masuda ◽  
Tomoki Ikoma ◽  
Koichi Masuda ◽  
Hisaaki Maeda
Keyword(s):  
Water Waves ◽  
Theoretical Calculations ◽  
Numerical Technique ◽  
Ocean Waves ◽  
Nonlinear Phenomena ◽  
Linear Potential ◽  
Floating Structure ◽  
Fully Nonlinear ◽  
Floating Structures ◽  
Mps Method

Very large floating structures (VLFSs) have been proposed for new ocean space utilization and many researches have been carried out. VLFSs are elastically deformed due to ocean waves because the rigidity of the structure decreases relatively. The authors examine the aircushion type floating structure in order to reduce hydroelastic motion. An aircushion type floating structure to which air-chambers are installed can reduce the wave drifting force and hydroelastic motion at the same time. Most theoretical calculations of motion of aircushion type floating structures in water waves have been done based on a linear potential theory so far. As a result, the utility of the aircushion has been proved. However fully nonlinear phenomena such as deck wetness, slamming and air-leakage cannot be investigated by using existing calculations based on the linear theory. In this study, a computer program code of the two-dimensional MPS method that can consider fully nonlinear influence is developed and then the air layer inside an aircushion is expressed with particles of the MPS. Moreover, the numerical technique for introducing directly the mooring force into the motion equation of the particle is developed. Motion response of aircushion type floating structures in a billow is computed. As a result, the usefulness of this numerical calculation method is confirmed.

Hydrodynamic Interactions of the Truncated Porous Vertical Circular Cylinder With Water Waves

2018 ◽  
Author(s):  
Charaf Ouled Housseine ◽  
Sime Malenica ◽  
Guillaume De Hauteclocque ◽  
Xiao-Bo Chen
Keyword(s):  
Circular Cylinder ◽  
Porous Body ◽  
Wave Diffraction ◽  
Water Waves ◽  
Expansion Method ◽  
Integral Equation Method ◽  
Boundary Integral ◽  
Diffraction Radiation ◽  
Linear Potential ◽  
Eigenfunction Expansion Method

Wave diffraction-radiation by a porous body is investigated here. Linear potential flow theory is used and the associated Boundary Value Problem (BVP) is formulated in frequency domain within a linear porosity condition. First, a semi-analytical solution for a truncated porous circular cylinder is developed using the dedicated eigenfunction expansion method. Then the general case of wave diffraction-radiation by a porous body with an arbitrary shape is discussed and solved through Boundary Integral Equation Method (BIEM). The main goal of these developments is to adapt the existing diffraction-radiation code (HYDROSTAR) for that type of applications. Thus the present study of the porous cylinder consists a validation work of (BIEM) numerical implementation. Excellent agreement between analytical and numerical results is observed. Porosity influence on wave exciting forces, added mass and damping is also investigated.

scholarly journals Model Analysis and System Parameters Investigation for Transient Wave in a Pump–Pipe–Valve System

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1014
Author(s):  
Zubin Liu ◽  
Dingyi Pan ◽  
Fengzhong Qu ◽  
Jianxin Hu
Keyword(s):  
Pressure Oscillation ◽  
Model Analysis ◽  
Matrix Analysis ◽  
Transient Wave ◽  
Long Distance ◽  
Valve System ◽  
Key Factor ◽  
Transfer Matrix Analysis ◽  
Distance Communication ◽  
Friction Models

The frequency responses of the transient wave propagating in a pump–pipe–valve system are studied with the system transfer matrix analysis (STMA) method. Being different to that in the reservoir–pipe–valve system, the transient wave is used as a long-distance communication technology in the pump–pipe–valve system, and very few works have been done on the model analysis and strategies to control the behavior of the oscillation signal of the pipe pressure. The theoretic solutions are studied with three internal friction models: frictionless, steady friction, and unsteady friction. The dimensionless parameter of the valve signal intensity (VSI) is proposed, and it is found to be a key factor affecting the quality of the wave propagation in the pipe. A larger pressure oscillation at the upstream side results when the VSI is smaller than one, whereas a more uniform amplitude for the resonances and anti-resonances is obtained when VSI approaches one. Some feasible suggestions are provided to obtain high quality wave signals.

OPTICAL BISTABILITY CONTROLLED USING ADD-DROP MOBIUS MICRORING RESONATOR SYSTEM

2016 ◽  
Vol 78 (3) ◽  
Author(s):  
Ahmad Fakhrurrazi Ahmad Noorden ◽  
Suzairi Daud ◽  
Syed Zuhaib Haider Rizvi ◽  
Jalil Ali ◽  
Preecha P. Yupapin
Keyword(s):  
Optical Switching ◽  
Optical Bistability ◽  
Input Power ◽  
Microring Resonator ◽  
Matrix Analysis ◽  
Hysteresis Width ◽  
Soliton Pulse ◽  
Transfer Matrix Analysis ◽  
Input Source ◽  
Resonator System

The theoretical investigation has been performed on the implementation of optical Mobius shape in add-drop microring resonator. The modified add-drop Mobius configuration is used to investigate the optical bistability and the spectral transmission. The optical bright soliton pulse is used as the input source of the resonator system. The pulses propagation of the resonator system is modelled using the iterative programming based on the transfer matrix analysis equations. The enhancement of nonlinear effect of the resonator system is achieved by the add-drop Mobius resonator configuration. The system has been modelled for a variation of coupling coefficient for increase the bistable signal properties. The Add-drop Mobius MRR generated a bistable signal with 6.01 mW hysteresis width, and 9.47 mW output switch power with optimized radius of 5 µm outer and 4.5 m inner ring parts with 50 mW controlled power and input power. Mobius configuration is found as the better shape of resonator cavity that capable of optical switching application. 

Sign in / Sign up

Export Citation Format

Share Document