scholarly journals Tidal Energy Flows between the Midriff Islands in the Gulf of California

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 621
Author(s):  
Federico Angel Velazquez-Muñoz ◽  
Anatoliy Filonov
Keyword(s):  
Kinetic Energy ◽  
Internal Wave ◽  
Gulf Of California ◽  
Current Flow ◽  
Tidal Flow ◽  
Three Dimensional ◽  
Tidal Energy ◽  
Ocean Model ◽  
Field Development ◽  
Wave Measurements

The Gulf of California has many regions of potential tidal-stream energy that have been identified and characterized using in-situ measurements and numerical ocean models. The Midriff Islands region has received particular attention due to its increased current speeds and high kinetic energy. This increase in energy can be seen in the formation of internal wave packets propagating for several hundred kilometers. Here we present a brief description of internal wave measurements travel towards the Northern Gulf and explore energy generation sites. In this paper we characterize the tidal inflow and outflow that passes throughout the Midriff Islands in the central part of the Gulf. We use a three-dimensional numerical ocean model that adequately reproduces the tidal flow and the increase in speed and kinetic energy between the islands. The current flow structure shows the highest velocity cores near the shore and far from the bottom. During the rising tide, the maximum current flow (~0.6 ms−1) was found between Turón Island and San Lorenzo Island, from the surface to 200 m depth. When the currents flowed out of the Gulf, during the falling tide, the maximum negative current (−0.8 ms−1) was found between Tiburon Island and Turón Island, from near the surface to 80 m depth. Although there are favorable conditions for power generation potential by tidal flows, the vertical variability of the current must be considered for field development and equipment installation sites.

scholarly journals Impact of Channel Geometry and Rotation on the Trapping of Internal Tides

2007 ◽  
Vol 37 (11) ◽  
pp. 2740-2763 ◽  
Author(s):  
Sybren Drijfhout ◽  
Leo R. M. Maas
Keyword(s):  
Continental Slope ◽  
Three Dimensional ◽  
Tidal Energy ◽  
Ocean Model ◽  
Internal Tides ◽  
Open Boundary ◽  
Kelvin Wave ◽  
Channel Geometry ◽  
Channel Slope ◽  
The Cross

Abstract The generation and propagation of internal tides has been studied with an isopycnic three-dimensional ocean model. The response of a uniformly stratified sea in a channel, which is forced by a barotropic tide on its open boundary, is considered. The tide progresses into the channel and forces internal tides over a continental slope at the other end. The channel has a length of 1200 km and a width of 191.25 km. The bottom profile has been varied. In a series of four experiments it is shown how the cross-channel geometry affects the propagation and trapping of internal tides, and the penetration scale of wave energy, away from the continental slope, is discussed. In particular it is found that a cross-channel bottom slope constrains the penetration of the internal tidal energy. Most internal waves refract toward a cross-channel plane where they are trapped. The exception is formed by edge waves that carry part of the energy away from the continental slope. In the case of rotation near the continental slope, the Poincaré waves that arise in the absence of a cross-channel slope no longer bear the characteristics of the wave attractor predicted by 2D theory, but are almost completely arrested, while the right-bound Kelvin wave preserves the 2D attractor in the cross-channel plane, which is present in the nonrotating case. The reflected, barotropic right-bound Kelvin wave acts as a secondary internal wave generator along the cross-channel slope.

scholarly journals Modeling Assessment of Tidal Energy Extraction in the Western Passage

2020 ◽  
Vol 8 (6) ◽  
pp. 411
Author(s):  
Zhaoqing Yang ◽  
Taiping Wang ◽  
Ziyu Xiao ◽  
Levi Kilcher ◽  
Kevin Haas ◽  
...  
Keyword(s):  
Cross Sections ◽  
Numerical Models ◽  
Three Dimensional ◽  
Energy Resource ◽  
Field Measurements ◽  
Tidal Energy ◽  
Resource Assessment ◽  
Ocean Model ◽  
Energy Extraction ◽  
Technical Specifications

Numerical models have been widely used for the resource characterization and assessment of tidal instream energy. The accurate assessment of tidal stream energy resources at a feasibility or project-design scale requires detailed hydrodynamic model simulations or high-quality field measurements. This study applied a three-dimensional finite-volume community ocean model (FVCOM) to simulate the tidal hydrodynamics in the Passamaquoddy–Cobscook Bay archipelago, with a focus on the Western Passage, to assist tidal energy resource assessment. IEC Technical specifications were considered in the model configurations and simulations. The model was calibrated and validated with field measurements. Energy fluxes and power densities along selected cross sections were calculated to evaluate the feasibility of the tidal energy development at several hotspots that feature strong currents. When taking both the high current speed and water depth into account, the model results showed that the Western Passage has great potential for the deployment of tidal energy farms. The maximum extractable power in the Western Passage was estimated using the Garrett and Cummins method. Different criteria and methods recommended by the IEC for resource characterization were evaluated and discussed using a sensitivity analysis of energy extraction for a hypothetical tidal turbine farm in the Western Passage.

scholarly journals Assessing the turbulent kinetic energy budget in an energetic tidal flow from measurements of coupled ADCPs

2020 ◽  
Vol 378 (2178) ◽  
pp. 20190496 ◽  
Author(s):  
Maxime Thiébaut ◽  
Jean-François Filipot ◽  
Christophe Maisondieu ◽  
Guillaume Damblans ◽  
Rui Duarte ◽  
...  
Keyword(s):  
Kinetic Energy ◽  
Turbulent Kinetic Energy ◽  
Production Rate ◽  
Tidal Flow ◽  
Tidal Energy ◽  
Reynolds Stresses ◽  
Common Assumption ◽  
Non Local ◽  
Tke Dissipation Rate ◽  
Acoustic Doppler Current Profilers

Two coupled four-beam acoustic Doppler current profilers were used to provide simultaneous and independent measurements of the turbulent kinetic energy (TKE) dissipation rate ε and the TKE production rate P over a 36 h long period at a highly energetic tidal energy site in the Alderney Race. The eight-beam arrangement enabled the evaluation of the six components of the Reynolds stress tensor which allows for an improved estimation of the TKE production rate. Depth-time series of ε, P and the Reynolds stresses are provided. The comparison between ε and P was performed by calculating individual ratios of ε corresponding to P . The depth-averaged ratio ε / P averaged over whole flood and ebb tide were found to be 2.2 and 2.8 respectively, indicating that TKE dissipation exceeds TKE production. It is shown that the term of diffusive transport of TKE is significant. As a result, non-local transport is important to the TKE budget and the common assumption of a local balance, i.e. a balance between production and dissipation, is not valid at the measurement site. This article is part of the theme issue ‘New insights on tidal dynamics and tidal energy harvesting in the Alderney Race’.

Exploring the Effect of Length and Angle on NACA 0010 for Diffuser Design in Tidal Current Turbines

2012 ◽  
Vol 201-202 ◽  
pp. 438-441 ◽  
Author(s):  
Nasir Mehmood ◽  
Liang Zhang ◽  
Jawad Khan
Keyword(s):  
Kinetic Energy ◽  
Tidal Current ◽  
Current Flow ◽  
Tidal Energy ◽  
Research Community ◽  
Financial Resources ◽  
Considerable Time ◽  
Tidal Turbines ◽  
Tidal Turbine

Tidal energy is one of the most predictable forms of renewable energy.Tides posses both potential and kinetic energy. Tidal energy can be utilized by capturing potential energy i.e. by means of tidal barrage and tidal fence or by capturing kinetic energy i.e. by menas of tidal current technologies. This study is focused on diffuser augmented tidal turbines that capture the kinetic energy. The power generated by a tidal turbine is directly proportional to the cube of velocity of current flow. The role of the diffuser in diffuser augmented tidal turbines is to help accelerate the incoming current velocity. Consequently, the efficiency of the turbine is significantly increasedby using adiffuser. The research community is investing considerable time and financial resources in thisgrowingdomain. The diffuser augmented tidal turbinesresearch datais rather scarce due to their emerging nature, large and costly research & development setup, startup cost and proprietary issues. The purpose of this paper is to study the effect of length and angle on NACA 0010airfoil for diffuser design. Numerical simulation is carried out to investigate velocity and mass flow rate at the throat. The drag force due to diffuser installation is also calculated.

scholarly journals Ocean model response to stochastically perturbed momentum fluxes

2021 ◽  
Author(s):  
Terence O'Kane ◽  
Russell Fiedler ◽  
Mark Collier ◽  
Vassili Kitsios
Keyword(s):  
Kinetic Energy ◽  
Climate Model ◽  
Weather Prediction ◽  
Three Dimensional ◽  
Dynamical Theory ◽  
Ocean Model ◽  
Energy Spectra ◽  
Small Scale ◽  
Model Errors ◽  
Momentum Fluxes

In climate model configurations, standard approaches to the representation of unresolved, or subgrid scales, via deterministic closure schemes are being challenged by stochastic approaches inspired by statistical dynamical theory. Despite gaining popularity, studies of various stochastic subgrid scale parameterizations applied to atmospheric climate and weather prediction systems have revealed a diversity of model responses, including degeneracy in the response to different forcings and compensating model errors, with little reduction in artificial damping of the small scales required for numerical stability. Due to the greater range of spatio-temporal scales involved, how to best sample subgrid fluctuations in a computationally inexpensive manner, with the aim of reduced model error and improvements to the simulated climatological state of the ocean, remains an open question. While previous studies have considered perturbations to the surface forcing or subsurface temperature tendencies, we implement an energetically consistent, simple, stochastic subgrid eddy parameterization of the momentum fluxes in regions of the three-dimensional ocean typically associated with high eddy variability. We consider the changes in the modelled energetics of low-resolution simulations in response to stochastically forced velocity tendencies whose perturbation statistics and amplitudes are calculated from an eddy resolving ocean configuration. Kinetic energy spectra from a triple-decomposition reveal a systematic redistribution from the seasonal (climatological minus mean) potential energy to preferentially generate small scale transient kinetic energy while the total energy spectra remains largely unchanged. We show that stochastic parameterization generally improves model biases, noticeably so for the simulated energetics of the Southern Oceans.

Three-Dimensional Numerical Model of Wind-Driven Current in a Lake Based on POM Model

2009 ◽  
Author(s):  
Jialing Hao ◽  
Xiaoxin Jiang ◽  
Juan Yang
Keyword(s):  
Numerical Modeling ◽  
Numerical Model ◽  
Flow Direction ◽  
Tidal Flow ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Ocean Model ◽  
Curvilinear Grid ◽  
Hydrodynamic Processes ◽  
Contaminant Transport Modeling

Lake current is the cause for the transport of many matters such as suspended sediment, algae, contaminant, therefore, it must be estimated fairly accurately. Generally speaking, the flow in many lakes is weak and the flow direction is follows dominated mainly by the wind direction on lake surface. Correct simulation of the wind-driven current in a lake requires using a three-dimensional hydrodynamic numerical model. The main factor affecting the lake hydrodynamic processes is wind. Because wind-driven current have important influence for the matter exchange and energy transform in a lake, and field observations are comparatively difficult, numerical modeling is the main method to estimate the wind-driven current nowadays. The numerical modeling of 3D tidal flow and mass transportation in this study was performed using the Princeton Ocean Model (POM). The model is validated by calculating wind-driven current in a rectangular flume [1][2]. The contaminant transport modeling in the Yangchenghu Lake is performed with POM using an orthogonal curvilinear grid in horizontal direction and sigma coordinate variation in vertical direction. An analysis of model results is presented.

scholarly journals Internal wave generation by oscillation of a sphere, with application to internal tides

2010 ◽  
Vol 666 ◽  
pp. 308-357 ◽  
Author(s):  
B. VOISIN ◽  
E. V. ERMANYUK ◽  
J.-B. FLÓR
Keyword(s):  
Wave Amplitude ◽  
Near Field ◽  
Oscillation Amplitude ◽  
Tidal Flow ◽  
Three Dimensional ◽  
Tidal Energy ◽  
Internal Gravity Waves ◽  
Internal Tides ◽  
Correlation Technique ◽  
The Waves

A joint theoretical and experimental study is performed on the generation of internal gravity waves by an oscillating sphere, as a paradigm of the generation of internal tides by barotropic tidal flow over three-dimensional supercritical topography. The theory is linear and three-dimensional, applies both near and far from the sphere, and takes into account viscosity and the unsteadiness arising from the interference with transients generated at the start-up. The waves propagate in conical beams, evolving with distance from a bimodal to unimodal wave profile. In the near field, the profile is asymmetric with its major peak towards the axis of the cones. The experiments involve horizontal oscillations and develop a cross-correlation technique for the measurement of the deformation of fluorescent dye planes to sub-pixel accuracy. At an oscillation amplitude of one fifth of the radius of the sphere, the waves are linear and the agreement between experiment and theory is excellent. As the amplitude increases to half the radius, nonlinear effects cause the wave amplitude to saturate at a value that is 20% lower than its linear estimate. Application of the theory to the conversion rate of barotropic tidal energy into internal tides confirms the expected scaling for flat topography, and shows its transformation for hemispherical topography. In the ocean, viscous and unsteady effects have an essentially local role, in keeping the wave amplitude finite at the edges of the beams, and otherwise dissipate energy on such large distances that they hardly induce any decay.

Modeling and Assessment of the Produced Water Discharges from Offshore Petroleum Platforms

2007 ◽  
Vol 42 (4) ◽  
pp. 303-310 ◽  
Author(s):  
Zhi Chen ◽  
Lin Zhao ◽  
Kenneth Lee ◽  
Charles Hannath
Keyword(s):  
Random Walk ◽  
Produced Water ◽  
Model Development ◽  
Three Dimensional ◽  
Monitoring Program ◽  
Ecological Monitoring ◽  
Numerical Approach ◽  
Ocean Model ◽  
Scale Model ◽  
Water Stream

Abstract There has been a growing interest in assessing the risks to the marine environment from produced water discharges. This study describes the development of a numerical approach, POM-RW, based on an integration of the Princeton Ocean Model (POM) and a Random Walk (RW) simulation of pollutant transport. Specifically, the POM is employed to simulate local ocean currents. It provides three-dimensional hydrodynamic input to a Random Walk model focused on the dispersion of toxic components within the produced water stream on a regional spatial scale. Model development and field validation of the predicted current field and pollutant concentrations were conducted in conjunction with a water quality and ecological monitoring program for an offshore facility located on the Grand Banks of Canada. Results indicate that the POM-RW approach is useful to address environmental risks associated with the produced water discharges.

Density Wave Measurements in a Rectangular Clarifier

1983 ◽  
Vol 18 (1) ◽  
pp. 129-150 ◽  
Author(s):  
Mark K. Watson ◽  
R.R. Hudgins ◽  
P.L. Silveston
Keyword(s):  
Power Spectrum ◽  
Internal Wave ◽  
Internal Waves ◽  
Wave Motion ◽  
Wave Amplitude ◽  
Suspended Solids ◽  
Small Volume ◽  
Density Wave ◽  
Measure Concentration ◽  
Wave Measurements

Abstract Internal wave motion was studied in a laboratory rectangular, primary clarifier. A photo-extinction device was used as a turbidimeter to measure concentration fluctuations in a small volume within the clarifier as a function of time. The signal from this device was fed to a HP21MX minicomputer and the power spectrum plotted from data records lasting approximately 30 min. Results show large changes of wave amplitude as frequency increases. Two distinct regions occur: one with high amplitudes at frequencies below 0.03 Hz, the second with very small amplitudes appears for frequencies greater than 0.1 Hz. The former is associated with internal waves, the latter with flow-generated turbulence. Depth, velocity in the clarifier and inlet suspended solids influence wave amplitudes and the spectra. A variation with position or orientation of the probe was not detected. Contradictory results were found for the influence of flow contraction baffles on internal wave amplitude.

A Real-Time Mathematical Model for Three-Dimensional Tidal Flow and Water Quality

1991 ◽  
Vol 24 (6) ◽  
pp. 171-177 ◽  
Author(s):  
Zeng Fantang ◽  
Xu Zhencheng ◽  
Chen Xiancheng
Keyword(s):  
Mathematical Model ◽  
Water Quality ◽  
Real Time ◽  
Control Volume ◽  
Tidal Flow ◽  
Three Dimensional ◽  
River Estuary ◽  
Pearl River Estuary ◽  
Practical Application ◽  
The Pearl River

A real-time mathematical model for three-dimensional tidal flow and water quality is presented in this paper. A control-volume-based difference method and a “power interpolation distribution” advocated by Patankar (1984) have been employed, and a concept of “separating the top-layer water” has been developed to solve the movable boundary problem. The model is unconditionally stable and convergent. Practical application of the model is illustrated by an example for the Pearl River Estuary.

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