scholarly journals Validation of a CFD-Based Numerical Wave Tank Model of the 1/20th Scale Wavestar Wave Energy Converter

Fluids ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 112
Author(s):  
Christian Windt ◽  
Nicolás Faedo ◽  
Demián García-Violini ◽  
Yerai Peña-Sanchez ◽  
Josh Davidson ◽  
...  
Keyword(s):  
Experimental Data ◽  
Numerical Model ◽  
Model Validation ◽  
Wave Energy ◽  
Test Case ◽  
Data Sets ◽  
Wave Energy Converters ◽  
Efficient Test ◽  
Numerical Wave ◽  
Wave Induced

Numerical wave tanks (NWTs) provide efficient test beds for the numerical analysis at various stages during the development of wave energy converters (WECs). To ensure the acquisition of accurate, high-fidelity data sets, validation of NWTs is a crucial step. However, using experimental data as reference during model validation, exact knowledge of all system parameters is required, which may not always be available, thus making an incremental validation inevitable. The present paper documents the numerical model validation of a 1/20 scale Wavestar WEC. The validation is performed considering different test case of increasing complexity: wave-only, wave excitation force, free decay, forced oscillation, and wave-induced motion cases. The results show acceptable agreement between the numerical and experimental data so that, under the well-known modelling constraints for mechanical friction and uncertainties in the physical model properties, the developed numerical model can be declared as validated.

scholarly journals Numerical model validation for mooring systems: Method and application for wave energy converters

2015 ◽  
Vol 75 ◽  
pp. 869-887 ◽  
Author(s):  
V. Harnois ◽  
S.D. Weller ◽  
L. Johanning ◽  
P.R. Thies ◽  
M. Le Boulluec ◽  
...  
Keyword(s):  
Numerical Model ◽  
Model Validation ◽  
Wave Energy ◽  
Wave Energy Converters ◽  
Energy Converters

Preliminary Cross-Validation of Wave Energy Converter Array Interactions

2013 ◽  
Author(s):  
Matt Folley ◽  
Trevor Whittaker
Keyword(s):  
Numerical Model ◽  
Wave Energy ◽  
Cross Validation ◽  
Wave Energy Converter ◽  
Energy Yield ◽  
Energy Converter ◽  
Wave Energy Converters ◽  
The Cost ◽  
Wave Farm ◽  
Energy Converters

The development of wave energy for utility-scale electricity production requires an understanding of how wave energy converters will interact with each other when part of a wave farm. Without this understanding it is difficult to calculate the energy yield from a wave farm and consequently the optimal wave farm layout and configuration cannot be determined. In addition, the uncertainty in a wave farm’s energy yield will increase the cost of finance for the project, which ultimately increases the cost of energy. Numerical modelling of wave energy converter arrays, based on potential flow, has provided some initial indications of the strength of array interactions and optimal array configurations; however, there has been limited validation of these numerical models. Moreover, the cross-validation that has been completed has been for relatively small arrays of wave energy converters. To provide some validation for large array interactions wave basin testing of three different configurations of up to 24 wave energy converters has been completed. All tests used polychromatic (irregular) sea-states, with a range of long-crested and short-crested seas, to provide validation in realistic conditions. The physical model array interactions are compared to those predicted by a numerical model and the suitability of the numerical and physical models analysed. The results are analysed at three different levels and all provide support for the cross-validation of the two models. The differences between the physical and numerical model are also identified and the implications for improving the modelling discussed.

scholarly journals Array modeling and testing of fixed OWC type Wave Energy Converters

2020 ◽  
Vol 3 (3) ◽  
pp. 137-143
Author(s):  
Bret Bosma ◽  
Ted Brekken ◽  
Pedro Lomonaco ◽  
Bryony DuPont ◽  
Chris Sharp ◽  
...  
Keyword(s):  
Numerical Model ◽  
Wave Energy ◽  
Average Power ◽  
Irregular Waves ◽  
Regular Waves ◽  
Wave Energy Converters ◽  
Phase Errors ◽  
Array Optimization ◽  
Tank Test ◽  
Energy Converters

If wave energy technology is to mature to commercial success, array optimization could play a key role in that process. This paper outlines physical and numerical modeling of an array of five oscillating water column wave energy converters. Numerical model simulations are compared with experimental tank test data for a non-optimal and optimal array layout. Results show a max increase of 12% in average power for regular waves, and 7% for irregular waves between the non-optimized and optimized layouts. The numerical model matches well under many conditions; however, improvement is needed to adjust for phase errors. This paper outlines the process of numerical and physical array testing, providing methodology and results helpful for researchers and developers working with wave energy converter arrays.

scholarly journals Evaluation of the overset grid method for control studies of wave energy converters in OpenFOAM numerical wave tanks

2019 ◽  
Vol 6 (1) ◽  
pp. 55-70 ◽  
Author(s):  
Christian Windt ◽  
Josh Davidson ◽  
Dominic D. J. Chandar ◽  
Nicolás Faedo ◽  
John V. Ringwood
Keyword(s):  
Wave Energy ◽  
Grid Method ◽  
Overset Grid ◽  
Wave Energy Converters ◽  
Overset Grid Method ◽  
Numerical Wave ◽  
Energy Converters

Validation of a Quasi-Linear Numerical Model of a Pitching Wave Energy Converter in Close Proximity to a Fixed Structure

2017 ◽  
Author(s):  
Pilar Heras ◽  
Sarah Thomas ◽  
Morten Kramer
Keyword(s):  
Numerical Model ◽  
Linear Theory ◽  
Wave Energy ◽  
Wave Theory ◽  
Domain Model ◽  
Linear Wave ◽  
Energy Devices ◽  
Wave Energy Converters ◽  
Close Proximity ◽  
Fixed Structure

Although linear theory is often used to analyse wave energy devices, it is in many cases too simplistic. Many wave energy converters (WECs) exceed the key linear theory assumption of small amplitudes of motion, and require the inclusion of non-linear forces. A common approach is to use a hybrid frequency-time domain model based on the Cummins equation with hydro-dynamic inputs coming from linear wave theory (Ref. [1]). Published experimental data is sparse (Ref. [2]) and the suitability for the broad variety of WEC technologies has yet to be proven. This paper focuses on the challenges faced when attempting to validate a numerical model of a WEC using a variety of scaled physical tests in a waveflume. The technology used as a case study in this paper is a pitching WEC in close proximity to a fixed structure. Challenges are presented relating to waveflume effects and obtaining accurate physical input parameters to the numerical model.

scholarly journals Ηydrodynamic Response and Produced Power of a Combined Structure Consisting of a Spar and Heaving Type Wave Energy Converters

Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 225
Author(s):  
Constantine Michailides
Keyword(s):  
Numerical Model ◽  
Wave Energy ◽  
Hydrodynamic Interaction ◽  
Numerical Models ◽  
Interaction Effects ◽  
Irregular Waves ◽  
Wave Power ◽  
Wave Energy Converters ◽  
Combined Structure ◽  
Energy Converters

During the past years, researchers have studied both numerically and experimentally multibody wave-wind combined energy structures supporting wind turbines and different types of Wave Energy Converters (WECs); rigid body hydrodynamic assumptions have been adopted so far for the development of their numerical models and the assessment of their produced power. In the present paper a numerical model that is based on the use of generalized modes addressing wave-structure interaction effects for the case of a multibody wave-wind combined structure is developed and presented. Afterwards, the developed numerical model is used for the assessment of the hydrodynamic response and the prediction of the produced power of different possible configurations of the updated WindWEC concept which consists of a spar supporting a wind turbine and one, two, three or four heaving type WEC buoys. The combined effects of the center-to-center distance of the WEC and spar platform, the number of the WECs and the grid configuration of spar and WECs on the hydrodynamic interaction between the different floating bodies, spar and WEC buoys, and consequently on their response and wave power production are examined for regular and irregular waves. Strong hydrodynamic interaction effects exist for small distance between spar and WECs that result to the decrease of the produced power. Power matrices of the updated WindWEC concept are presented for all examined configurations with different number of WECs. Moreover, the annual produced power of the updated WindWEC in two sites is estimated and presented. The generalized modes analysis presented in this paper is generic and can be used for the early stage assessment of wave-wind combined energy structures with low computational cost. The updated WindWEC can be used in sea sites with different environmental characteristics while extracting valuable amount of wave power.

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