scholarly journals MATHEMATICAL MODELLING OF WAVE-INDUCED NEARSHORE CIRCULATIONS

1986 ◽  
Vol 1 (20) ◽  
pp. 122 ◽  
Author(s):  
Donghoon Yoo ◽  
Brian A. O'Connor
Keyword(s):  
Experimental Data ◽  
Present Model ◽  
Wave Climate ◽  
Mixing Processes ◽  
Diffraction Wave ◽  
Waves And Currents ◽  
Current Interaction ◽  
Induced Currents ◽  
Set Up ◽  
Wave Induced

The paper presents a mathematical model for describing wave climate and wave-induced nearshore circulations. The model accounts for current-depth refraction, diffraction, wave-induced currents, set-up and set-down, mixing processes and bottom friction effects on both waves and currents. The present model was tested against published experimental data on wave conditions within a model harbour and shown to give very good results for both wave and current fields. The importance of including processes such as advection, flooding and current-interaction in coastal models was demonstrated by comparing the numerical results without each process to the results from the complete scheme.

scholarly journals Iteration Coupling Simulation of Random Waves and Wave-Induced Currents

2012 ◽  
Vol 2012 ◽  
pp. 1-13
Author(s):  
Jinhai Zheng ◽  
Tianwen Wang ◽  
Gang Wang ◽  
Chenming Zhang ◽  
Chi Zhang
Keyword(s):  
Wave Field ◽  
Circulation Model ◽  
Wave Transformation ◽  
Induced Current ◽  
Random Waves ◽  
Three Dimensional Model ◽  
Current Interaction ◽  
Induced Currents ◽  
Coupling Algorithm ◽  
Wave Induced

A two-way coupling algorithm for wave-current interaction is developed and implemented into a nearshore circulation model to investigate the effects of fully wave-current interaction on irregular wave transformation over an elliptic shoal. The wave field is simulated by a spectral wave model WABED, and the wave-induced current is solved by a quasi-three-dimensional model WINCM. The surface roller effects are represented in the formulation of surface stress, and the roller characteristics are solved by a roller evolution model. The proposed two-way coupling algorithm can describe both the generation of wave-induced current and the current-induced wave transformation, which is more physically reasonable than the one-way approaches. The model test with a laboratory experiment shows that wave-induced currents have an important influence on the wave transformation, for example, the wave energy defocusing due to the strong jet-like current along the centerline of the shoal. It is revealed that the accuracy of simulated wave field can be significantly improved by taking into account the two-way wave-current interaction.

scholarly journals WAVE - INDUCED DEVICES FOR THE OXYGENATION OF DEEP LAYER: A PHYSICAL INVESTIGATION

2012 ◽  
Vol 1 (33) ◽  
pp. 56 ◽  
Author(s):  
Alessandro Antonini ◽  
Maria Gabriella Gaeta ◽  
Alberto Lamberti
Keyword(s):  
Atlantic Coast ◽  
Water Flux ◽  
Vertical Mixing ◽  
Wave Climate ◽  
Environmental Variable ◽  
Mixing Processes ◽  
Coastal Marine ◽  
Short Period ◽  
Ecological Importance ◽  
Wave Induced

No other environmental variable of ecological importance to estuarine and coastal marine ecosystems around the world has changed so drastically, in such a short period of time, as dissolved oxygen. Coastal surveys in United States and Europe found that a staggering 78 % of the assessed continental U.S. coastal area and approximately 65 % of Europe’s Atlantic coast exhibit symptoms of eutrophication. The 65 % of the coasts counted by Diaz does not take into account inland seas like the Adriatic or Baltic Seas but also for these, eutrophication and consequently anoxia are common problems. In the present study a simple and economic device is proposed to enhance vertical mixing processes and to induce aeration of deep water by pumping of oxygen-rich surface water downwards to a desired depth around the halocline. The hydrodynamic parameters of the device are estimated through free oscillation tests. Preliminary values of the downward water flux velocity inside the device and the movements of the floater under the action of 4 regular waves, characterizing of the wave climate in the Nord Adriatic Sea, are estimated.

scholarly journals Comparison of Measured Surface Currents from High Frequency (HF) and X-Band Radar in a Marine Protected Coastal Area of the Ligurian Sea: Toward an Integrated Monitoring System

2020 ◽  
Vol 12 (18) ◽  
pp. 3074
Author(s):  
Lyuba Novi ◽  
Francesco Raffa ◽  
Francesco Serafino
Keyword(s):  
High Frequency ◽  
Hf Radar ◽  
Surface Currents ◽  
Integrated Monitoring ◽  
Ligurian Sea ◽  
X Band ◽  
Waves And Currents ◽  
Induced Currents ◽  
The Difference ◽  
Wave Induced

Two different ground-based remote sensing instruments can be used for the near-real-time monitoring of surface waves and currents, namely the high frequency HF radar and the microwave X-band radar. The HF system reaches larger offshore distances at lower spatial resolutions and provides a poorer measurement of the wave-induced currents in very shallow waters. On the other hand, the X-band system achieves significantly higher spatial resolutions with a smaller offshore coverage. This study provides a preliminary comparison of the measured surface currents, obtained by the two different tools where they overlap. The comparison showed a good agreement between the measures with some discrepancies ascribable to the difference in the characteristics of the two radar technologies.

scholarly journals Numerical simulation of the three-dimensional wave-induced currents on unstructured grid

2017 ◽  
Vol 31 (5) ◽  
pp. 539-548
Author(s):  
Ping Wang ◽  
Ning-chuan Zhang ◽  
Shuai Yuan ◽  
Wei-bin Chen
Keyword(s):  
Numerical Simulation ◽  
Unstructured Grid ◽  
Three Dimensional ◽  
Induced Currents ◽  
Wave Induced ◽  
Dimensional Wave

Numerical Modeling of Seabed Response to Combined Wave-Current Loading

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
J.-S. Zhang ◽  
Y. Zhang ◽  
C. Zhang ◽  
D.-S. Jeng
Keyword(s):  
Numerical Modeling ◽  
Stokes Equations ◽  
Navier Stokes ◽  
Laboratory Measurements ◽  
Navier Stokes Equations ◽  
Closure Scheme ◽  
Waves And Currents ◽  
Current Interaction ◽  
Wave Maker ◽  
Current Loading

In this paper, a numerical model is developed to study the dynamic response of a porous seabed to combined wave-current loadings. While the Reynolds-averaged Navier–Stokes equations with k-ε turbulence closure scheme and internal wave-maker function are solved for the phenomenon of wave-current interaction, Biot's poro-elastic “u-p” model is adopted for the seabed response. After validated by the laboratory measurements, this model is applied for the investigation of the effects of waves and currents on the wave-current induced pore pressures. Furthermore, the effects of currents on maximum liquefaction depths of a porous seabed is examined, and it is concluded that the opposite currents will increase the liquefaction depth up to 30% of that without currents.

Leakage Flow Investigations on a Through-Wall Crack Related to Thermal Fatigue of Nuclear Power Plant Piping

2017 ◽  
Author(s):  
Stefan Schmid ◽  
Rudi Kulenovic ◽  
Eckart Laurien
Keyword(s):  
Experimental Data ◽  
Nuclear Power ◽  
Numerical Models ◽  
Measurement Techniques ◽  
Experimental Investigations ◽  
Leakage Flow ◽  
Test Rig ◽  
Reduced Pressure ◽  
Flow Rates ◽  
Set Up

For the validation of empirical models to calculate leakage flow rates in through-wall cracks of piping, reliable experimental data are essential. In this context, the Leakage Flow (LF) test rig was built up at the IKE for measurements of leakage flow rates with reduced pressure (maximum 1 MPA) and temperature (maximum 170 °C) compared to real plant conditions. The design of the test rig enables experimental investigations of through-wall cracks with different geometries and orientations by means of circular blank sheets with integrated cracks which are installed in the tubular test section of the test rig. In the paper, the experimental LF set-up and used measurement techniques are explained in detail. Furthermore, first leakage flow measurement results for one through-wall crack geometry and different imposed fluid pressures at ambient temperature conditions are presented and discussed. As an additional aspect the experimental data are used for the determination of the flow resistance of the investigated leak channel. Finally, the experimental results are compared with numerical results of WinLeck calculations to prove specifically in WinLeck implemented numerical models.

TEMPERATURE DEPENDENCE OF THERMODYNAMIC PROPERTIES OF IONIC SOLIDS

2009 ◽  
Vol 23 (11) ◽  
pp. 2503-2509 ◽  
Author(s):  
S. K. SHARMA
Keyword(s):  
Experimental Data ◽  
Temperature Dependence ◽  
Volume Expansion ◽  
Close Agreement ◽  
Present Model ◽  
Expansion Ratio ◽  
Thermal Expansivity ◽  
Temperature Derivative ◽  
Computing Model ◽  
Ionic Solids

The present paper proposes a computing model for temperature dependence of volume thermal expansivity, volume expansion ratio and second order temperature derivative of volume based on the assumption that the product αKT remains constant at high temperatures and zero pressure. We have taken NaCl and KCl to testify the validity of the present model. A fairly close agreement between the calculated results and experimental data strongly supports the present model.

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