AndreaBozzo/ceres-open-data-index huggingface dataset:
Centipod WEC, Survivable Wave Energy Converters, Final Technical Report

This project shows that the choice of a secondary DOF for survivability is a viable option to reduce the levelized cost of energy (LCOE) in WEC designs. This report will cover the calculation of the concluded LCOE advantage using Dehlsen Associates’ “Centipod” WEC, but will also discuss the entire project from start to finish, including mid and high-fidelity modeling, survival mode trade study, wave basin testing, and design tool cross-verification and validation.

Tags: carderock, carderock-mask, ceptipod, cfd, degree-of-freedom, dehlsen-associates, ecm, economics, energy, extreme-condition-modeling, extreme-conditions, fea, high-fidelity, hydrokinetic, lcoe, levelized-cost-of-energy, load-mitigation, marine, marine-and-seakeeping, mhk, mid-fidelity, modeling, naval-surface-warfare-center, power, secondary-dof, survivable, wave, wave-basin, wavedyn, wec
Organization: Department of Energy
StingRAY Structural Optimization Final Technical Report

The overall project objective is to materially decrease the leveled cost of energy (LCOE) of the Columbia Power (CPower) StingRAY utility-scale wave energy converter (WEC). This will be achieved by reducing structural material and manufacturing costs and increasing energy output. In this Project, improving the overall Power-to-Weight ratio (PWR) is accomplished through lowering design margins?allowing for weight reduction and more efficient, cost-effective WEC manufacturing and assembly?and by optimizing mass-related WEC performance parameters, such as center of gravity and system inertia.

A mixed materials approach to further structural optimization was developed under this Project and validated with extensive laboratory structural testing. This approach substitutes fiber-reinforced plastic (FRP) for steel where appropriate. The benefits of steel are maintained where most useful, for instance at structural joints where the stiffness of steel is required, and the complex geometry is more readily fabricated with steel. However, there are structural spans whose simple shapes are readily fabricated with mandrel-wound FRP and where significant cost and weight savings can be found. An adhesive, double lap shear joint is used to join the FRP and steel subcomponents.


Tags: fiber-reinforced-plastic, frp, hull, hybrid-materials, hydrokinetic, lcoe, marine, mhk, offshore, renewable-energy, structure, wave-energy-converter
Organization: Department of Energy
TEAMER: Numerical Model of IProTech PIP WEC Device

iProTech PIP wave energy converter (WEC) is a slack moored, single hull device with no moving parts in the water, joints or bearings. This submission includes data of the simulation, reports, and code for the iProTech PIP (WEC) project. The organization of the data included in the provided archive is detailed below and in the data description of the archive.

The data teamer-iprotech-nrel folder includes and explains matlab and python code developed to hydrodynamically model the PIP WEC device in WEC-Sim. The subfolders cover the following steps: 
1) report: explanatory information on device geometry
2) pip_mesher: python code to generate mesh panels from device profile data
3) wec-sim_models: matlab code to run WEC-Sim
The data uploaded is a snapshot as of 11/02/2121 of code residing in a Github repository administered by David Ogden of NREL.

Project was funded as part of the TEAMER RFTS 1 (request for technical support) program.

Tags: active-pto, code, geometry, geometry-investigation, iprotech, matlab, model, pip-pitching-inertial-pump, pto, pto-sim, python, rfts-1, simulation, teamer, wave-energy-capture, wec, wec-sim, wec-sim-numerical-model
Organization: Department of Energy
Lift Equivalence and Cancellation for Airfoil Surge-Pitch-Plunge Oscillations

A NACA 0018 airfoil in freestream velocity is oscillated in longitudinal, transverse, and angle-of-attack directions with respect to the freestream velocity, known as surge, plunge, and pitch. The lift-based equivalence method introduces phase shifts between these three motions to construct in-phase sinusoidal components for maximum lift, waveform construction. Lift cancellation is also determined with the exact negative pitch and plunge motion amplitudes found from the equivalence method to achieve out-of-phase wave destruction. Lift cancellation occurs when a combination of these motions is sought to obtain a constant lift magnitude throughout the oscillation cycle. To achieve both equivalence and cancellation of lift, a prescribed pure pitch amplitude through the Theodorsen theory equates the corresponding equivalent plunge amplitude and pitch-plunge phase shift. These Theodorsen, linear superposition findings of pitch-plunge are leveraged toward the Greenberg theory to determine a closed-form, surge-pitch-plunge solution through the addition of a surge-plunge phase shift and optimal surge amplitude for lift cancellation. The lift cancellation surge-pitch-plunge amplitudes define the equivalence amplitude investigated here and theoretically limit the experiment to combinations of the first lift harmonic of the Greenberg theory. The analytical results are then compared with experimental lift force measurements and dye visualization. The normalized lift differences due to unsteady wake and boundary-layer behavior are examined to explore the extents of the Greenberg theory for these cases of lift-based equivalence and cancellation.

Tags: 0012, 0018, airfoil, cancellation, dye-visualization, energy, equivalence, experiment, experimental, foil-theory, greenberg, hydrokinetic, lab-test, leading-edge-vortex, lev, lift, lift-based, marine, mhk, naca, naca-0018, normalized-lift, oscillation, phase-shift, pitch, pitch-plunge, plunge, power, quasi-steady, surge, surge-pitch-plunge, surge-plunge, test, theodersen, water-tunnel
Organization: Department of Energy
Observation-Based Resource Assessment of Gulf Stream MHK

Multi-year measurements of current velocity, salinity, and temperature from fixed and vessel-mounted sensors quantify Gulf Stream (GS) MHK resource variability and inform development off Cape Hatteras, NC. Vessel transects across the GS demonstrate a jet-like velocity structure with speeds exceeding 2.5 m/s at the surface, persistent horizontal shear throughout the jet, and strongest vertical shears within the cyclonic shear zone. Persistent equatorward flow at the base of the GS associated with the Deep Western Boundary Current (DWBC) produces a local maximum in vertical shear where stratification is weak and is postulated to be a site of strong turbulent mixing. Repeated transects at the same location demonstrate that the velocity structure depends upon whether the GS abuts the shelf slope or is offshore.

Tags: acoustic-doppler-current-profiler, adcp, cape-hatteras, characterization, control-temperature-depth, ctd, current, energy, gulf-stream, hydrokinetic, marine, mhk, mooring, north-carolina, ocean, oceanography, power, resouce, resource-assessment, velocity
Organization: Department of Energy
Control of an AUV with deployable energy-harvesting kite

This paper examines the control of an autonomous underwater vehicle (AUV) with a deployable energy-harvesting kite for oceanographic observation and surveillance. The proposed design and control strategies specifically address objectives of achieving high-payload, long-endurance AUV operation through the deployment of an energy-harvesting kite while the AUV is anchored to the seabed, followed by the retraction of the kite for continued operation of the AUV. While deployed, the kite executes power-augmenting cross-current flight motions, using a hierarchical controller. When the AUV is in motion and the kite is retracted, a dynamic programming-based controller is used to select charging locations that minimize total charging time when traversing a prescribed mission path. Focusing on oceanographic observation along a Gulf Stream transect, using a hindcast model of the Gulf Stream current resource, the paper demonstrates the efficacy of the proposed control approach, as compared to several non-optimized alternatives.

Tags: auv, cec, control, current, energy, gulf-stream, hindcast, hydrokinetic, kite, long-endurance, marine, mhk, observation, ocean, path, power, tidal-kite
Organization: Department of Energy
Spooling control design for flight optimization of tethered tidal kites

This submission includes three peer-reviewed (under review) papers from the researchers at North Carolina State University presenting different control-based techniques to maximize the efficiency and robustness of a tethered energy-harvesting kite. Below are the abstracts of each file included in the submission.

Naik ACC - Geometric Structural Control Co-Design.pdf
Focusing on a marine hydrokinetic energy application, this paper presents a combined geometric, structural, and control co-design framework for optimizing the performance of energy-harvesting kites subject to structural constraints. While energy-harvesting kites can offer more than an order of magnitude more power per unit of mass than traditional fixed turbines, they represent complex flying devices that demand robust, efficient flight controllers and are presented with significant structural loads that are larger with more efficient flight.

Daniels IFAC - Optimal Cyclic Spooling Control.pdf
This paper presents a control strategy for optimizing the the spooling speeds of tethered energy harvesting systems that generate energy through cyclic spooling motions which consist of high-tension spool-out and low-tension spool-in. Specifically, we fuse continuous-time optimal control tools, including Pontryagin?s Maximum Principle, with an iteration domain costate correction, to develop an optimal spooling controller for energy extraction. In this work, we focus our simulation results specifically on an ocean kite system where the goal is to optimize the spooling profile while remaining at a consistent operating depth and corresponding average tether length.

Reed IFAC - Kite Control in Turbulence.pdf
This paper presents a hierarchical control framework for a kite-based MHK system that executes power-augmenting cross-current flight, along with simulation results based on a high-fidelity turbulent flow model that is representative of flow conditions in the Gulf Stream. The hierarchical controller is used to robustly regulate both the kite?s flight path and the intra-cycle spooling behavior, which is ultimately used to realize net positive energy production at a base station motor/generator system. Two configurations are examined in this paper: one in which the kite is suspended from a surface-mounted platform, and another in which the kite is deployed from the seabed.


Tags: cec, control, controller, costate-correction, cross-current, cyclic-spooling, design, energy, flight, flight-optimization, geometric, gulf-stream, hydrofoil, hydrokinetic, marine, mhk, model, modeling, ocean-current, optimal, plant, pontryagins-maximum-principle, power, spooling, structural, tidal-kite, turbulent-flow, winch
Organization: Department of Energy
TriFrame Mount Structural Performance - Period A

Long-Term TriFrame Monitoring System (LTTFMS) data collected during Period A (13 days - 10/22/20 - 11/4/20). The central component of the Verdant Power Free Flow System is a three-bladed horizontal-axis turbine.  The turbine is equipped with a composite rotor with three fixed-pitch blades that rotate at a slow and regular rate (approx. 32 rpm), well below normal water vessel propeller speeds and conventional hydropower turbine blade speeds. The TriFrame mount is the structural mount that holds the three Verdant Power three-bladed horizontal-axis turbines.

Tags: axial-turbine, data, energy, hydrokinetic, marine, material-performance, mhk, mount, perfomance, power, rite, structural-mount, structure-performance, stucture, triframe
Organization: Department of Energy
MBARI WEC 2021 deployment

This dataset includes data from the Monterey Bay Aquarium Research Institute (MBARI) wave energy converter (WEC) and a nearby located Sofar Spotter buoy. The Monterey Bay Aquarium Research Institute has developed and deployed a small two-body point absorber wave energy device suitable to autonomous underwater vehicle, sensor system, and even aquaculture farm needs. For more information on the MBARI WEC see the research journal attached in the submission.

Tags: advanced-wec-dynamics-and-controls, energy, environmental-data, hydrokinetic, marine, mbari, mhk, monterey, monterey-bay, point-absorber, point-absorber-buoy, production-data, pto, raw-data, sandia, sofar-spotter-buoy, spotter-buoy, spotter-data, wave-data, wave-energy, wec
Organization: Department of Energy
Model and experimental validation of ocean kite dynamics and controls

This submission includes two peer-reviewed papers from researchers at North Carolina State University presenting the modeling and lab-scale experimentation of the dynamics and control of a tethered tidal ocean kite. Below are the abstracts of each file included in the submission.

Alvarez ECC: Flight and Tether Dynamics
This paper models the dynamics of a marine tethered energy harvesting system focusing on exploring the sensitivity of the kite dynamics to tether parameters. These systems repetitively reels a kite out at high tension, then reels it in at low tension, in order to harvest energy. The kite?s high lift-to-drag ratio makes it possible to maximize net energy output through periodic cross-current flight.  Significant modeling efforts exist in the literature supporting such energy maximization. The goal of this paper is to address the need for a simple model capturing the interplay between the system?s kite and tether dynamics. The authors pursue this goal by coupling a partial differential equation (PDE) model of tether dynamics with a point mass model of translational kite motion.

Siddiqui JDSMC: Lab-scale closed-loop model and validation
This paper presents a study wherein we experimentally characterize the dynamics and control system of a lab-scale ocean kite, and then refine, validate, and extrapolate this model for use in a full-scale system. Ocean kite systems, which harvest tidal and ocean current resources through high-efficiency cross-current motion, enable energy extraction with an order of magnitude less material (and cost) than stationary systems with the same rated power output. However, an ocean kite represents a nascent technology that is characterized by relatively complex dynamics and requires sophisticated control algorithms. In order to characterize the dynamics and control of ocean kite systems rapidly, at a relatively low cost, the authors have developed a lab-scale, closed-loop prototyping environment for characterizing tethered systems, whereby 3D printed systems are tethered and flown in a water channel environment.

Tags: cec, closed-loop, control, controller, drag, dynamics, energy, experimental-characterization, flight, hydrofoil, hydrokinetic, lab-scale, lab-test, lift, lift-to-drag-ratio, marine, mhk, model, modeling, ocean, ocean-kite, point-mass-model, power, tether, tethered, tidal, tidal-kite, validation
Organization: Department of Energy
Performance estimation of resonance-enhanced dual-buoy wave energy converter using coupled time-domain simulation

This paper presents the modeling methodology and performance evaluation of the resonance-enhanced dual-buoy WEC (Wave Energy Converter) by HEM (hydrodynamic & electro-magnetic) fully-coupled-dynamics time-domain-simulation program. The numerical results are systematically compared with the authors' 1/6-scale experiment. With a direct-drive linear generator, the WEC consists of dual floating cylinders and a moon-pool between the cylinders, which can utilize three resonance phenomena from moon-pool dynamics as well as heave motions of inner and outer buoys. The contact and friction between the two buoys observed in the experiment are also properly modeled in the time-domain simulation by the Coulomb-friction model. Moon-pool resonance peaks significantly exaggerated in linear potential theory are empirically adjusted through comparisons with measured values. A systematic comparative study between the simulations and experiments with and without PTO (power-take-off) is conducted, and the relative heave displacements/velocities and power outputs are well matched. Then, parametric studies are carried out with the simulation program to determine optimum generator parameters. The performance with various wave conditions is also assessed.

Highlights:
1. Dual-cylinder wave energy converter with moon-pool is designed to use three resonances.
2. Interaction between the dual cylinder and the linear generator is solved in time domain.
3. The proposed simulation model correlated to the experiments provides coincided results with experiments.
4. Moon-pool and guiding mechanisms between the cylinders influence dynamic response and power notably.
5. Optimum parameters of the linear generator are found using the correlated model.

Tags: coulomb-friction-model, displacement, dual-cylinder, dynamics, energy, experiment, heave, hem, hydrodynamic-electro-magnetic, hydrokinetic, linear-generator, marine, mhk, model, modeling, moon-pool, point-absorber, point-absorber-buoy, power, pto, resonance, simulation, surface, time-domain, velocity, wec
Organization: Department of Energy
WEC Controls Optimization Final Report

The over-arching project objective is to fully develop and validate optimal controls frameworks that can subsequently be applied widely to different WEC devices and concepts. Optimal controls of WEC devices represent a fundamental building block for WEC designers that must be considered as an integral part of every stage of device development. Using a building-blocks approach to optimal controls development, this effort will result in the full development of a feed-forward and feed-back control approach and a wave prediction system.

Phase I focused primarily on numerical offline optimization and validation using wave tank testing of three industry partners? WEC devices, including CalWave, Ocean Energy, and Resolute Marine Energy. These industry partnerships allowed us to identify optimal control strategies for these different WEC topologies at different maturity levels. Phase II focused on demonstrating an integrated control system on a custom-built prototype for at-sea testing. A secondary focus during phase II is to adapt our systems identification, controls and wave-prediction frameworks to become more robust and comprehensive in respect to capability, robustness, and reliability. RE Vision Consulting leads this project and has compiled the final public domain report included in this submission.

Tags: at-sea, causal-control, control, controls-optimization, cost-assessment, economics, energy, feed-back, feed-forward, feedback-control, heaving, hinsdale-wave-research-laboratory, hydrokinetic, in-ocean-test, labview, marine, mhk, model-predictive-control, mpc, ocean-energy, open-water, oregon-state-university, point-absorber-buoy, power, power-take-off, pto, resolute-marine-energy, sensitivity, surge-converter, techno-economic, wave, wave-prediction-error, wec
Organization: Department of Energy
Net Shape Fabricated Low Cost MHK Pass-Through the Hub Turbine Blades with Integrated Health Management Technology

The primary objective of this project is to develop a three-blade MHK rotor with low manufacturing and maintenance costs. The proposed program will design, fabricate and test a novel half-scale low cost, net shape fabricated single piece three-blade MHK rotor with integrated health management technology to demonstrate significant Capital Expenditures (CAPEX) and Operational Expenditures (OPEX) cost reductions due to the novel design and manufacturing process. 
The proposed project is divided into three major tasks:

Task 1: Single Piece Three-blade Kinetic Hydropower System (KHPS) Rotor Full-Scale and Half-Scale Design; 
Task 2: Composite Manufacturing Trials and Half-Scale Prototype Rotor Fabrication; and 
Task 3: Material Characterization and Half-Scale Prototype Test and Evaluation.

These three tasks include design and analysis of full-scale and half-scale three-blade rotor prototypes using computational fluid dynamics (CFD) and finite-element analysis (FEA), demonstration of a novel half-scale net shape fabrication process, determination of a fatigue threshold composite strain allowable, three-blade rotor mold design, manufacture of half-scale rotor clam shell mold, three-blade rotor test fixture design and fabrication, development of final manufacturing and test plans, manufacture of the half-scale net shape composite single blade and three-blade prototypes, and test and evaluation of the half-scale rotor.

Tags: adv, as-fabricated, axial-flow-turbine, cad, capex, cec, cfd, composite-materials, economics, fabrication, fast, fatigue-test, fea, flow, gen5d, health-management, hydrokinetic, khps, kinetic-hydropower-system, modeling, net-shape-fabrication, opex, over-rel, rite, rotor, simulation, steady-state, strain, stress, test-and-evaluation, three-blade, threshold-fatigue, transient, verdant-power, visualization, vp
Organization: Department of Energy
2017 Western Passage Tidal Energy Resource Characterization Measurements

These data are from tidal resource characterization measurements collected between April and July 2017 in Western Passage near Eastport, Maine, USA.

The dataset contains the following four sub-datasets, each of which is described in more detail in the README.pdf.

1. A bottom-mounted Teledyne RDI Workhorse 600 kHz acoustic Doppler current profiler (ADCP) was deployed at 44.92015 N, 66.98915 W in ~50 m of water from 3 April to 18 July (106 days). Data were recorded in 6-minute increments in the ENU (East, magnetic North, Up) coordinate system with bin-mapping enabled.

2. A bottom-mounted Nortek Signature 500 kHz ADCP was deployed at 44.92192 N, 66.98913 W in ~50 m of water from 4 April to 18 July (105 days). Data were sampled and recorded at 2 Hz and recorded in the ENU (East, magnetic North, Up) coordinate system.

3. Between those stations along a cross-channel transect, a Stable Tidal Turbulence Mooring (STTM) positioned ~10 m above the seabed was deployed for one week during a spring tide. The STTM was outfitted with two Nortek Vector acoustic Doppler velocimeters equipped with inertial motion units (ADVs), a bottom-tracking downward-looking Teledyne RDI Workhorse 600 kHz ADCP to provide motion-corrected flow and turbulence characteristics at high temporal resolution, and an upward-looking Teledyne RDI Sentinel V20 ADCP. The STTM was deployed at 44.92098 N, 66.98922 W from 24-31 May.

4. A vessel-mounted Teledyne RDI Workhorse 300 kHz ADCP collected current data along three transects over two days, 4-5 April.

The data processing used DOLfYN version 0.11.2. All hdf5 files (i.e., files ending in `.h5`) contained here can be opened using that version of DOLfYN (e.g., `dat = dolfyn.load('')`).

All distances are in meters (e.g., depth, range, MLLW, hab, eta, z_), and all velocities in m/s. See the DOLfYN documentation https://lkilcher.github.io/dolfyn/), and/or the Nortek and Teledyne RDI documentation for additional details.

Additional details on the dataset can be found in the README.pdf, including:
- Format details of each data file.
- How to regenerate the data-processing (using the files in the `wp2017_processing.zip` archive).


Tags: acoustic-doppler-current-profiler, adcp, air-pressure, depth, dolfyn, energy, flow, height, hydrokinetic, maine, marine, marine-energy-resource-assessment-and-characterization, matlab, mean-lower-low-water, mhk, mllw, nortek, ocean-contour, power, processed-data, raw-data, rdi-sentinel, rdi-workhorse, resource, resource-assessment, resource-characterization, sea-surface-height, stable-tidal-turbulence-mooring, stablemoor, sttm, teledyne, tidal, turbulence, velocimetry, velocity, western-passage
Organization: Department of Energy