Proceedings of the European Wave and Tidal Energy Conference最新文献

{"title":"Relevance of Robustness and Uncertainties Analysis in the Optimal Design of Wave Energy Converters","authors":"Filippo Giorcelli, S. Sirigu, Dario Basile","doi":"10.36688/ewtec-2023-352","DOIUrl":"https://doi.org/10.36688/ewtec-2023-352","url":null,"abstract":"The optimisation design of Wave Energy Converters (WEC) to reduce the cost of energy of the technology is a widely investigated topic. In literature classical optimisation strategies have been presented and applied to identify the optimal system parameters of WECs to optimise specific techno-economic metrics. The performance of the optimal identified devices relies on these nominal parameters and it can be strongly affected by construction and modelling uncertainties. In this context, the concept of robustness of the optimal solution plays a relevant role in the identification of a device whose performance is affected as little as possible by uncertainties of various kinds. In the first part of this paper different declinations of robustness concept are derived from other fields of application and described. The identified robustness indexes are then applied to optimal solutions obtained via classical optimisation to evaluate its importance in the design process of WECs. \u0000Strictly related to this kind of methodology is the Sensitivity Analysis (SA) technique, it aims to investigate how the input variation (due to uncertainties or external noise or additional environmental parameters) influences the output results of a defined numerical model and highlight the relative input parameters relevance. Sensitivity Analysis, therefore, can be a valuable tool applicable in the uncertainty set estimation to identify the variables most subject to such uncertainties and their prominence. \u0000The main objective of the work is to underline the importance of introduce the robustness evaluation of WECs during the optimisation process since classical optimisation techniques can lead to solutions that are affected by uncertainties.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131980966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Siting tidal energy projects through resource characterization and environmental considerations","authors":"A. Copping, Lysel Garavelli, Zhaoqing Yang, Taiping Wang, Mithun Deb, Candace Briggs","doi":"10.36688/ewtec-2023-220","DOIUrl":"https://doi.org/10.36688/ewtec-2023-220","url":null,"abstract":"The development of tidal energy technologies has progressed to where devices can be deployed, operated, maintained, and recovered with some level of assurance that they will and produce adequate levels of power. Equally important to further the tidal energy industry is the ability to site and gain regulatory permission to deploy and operate these devices. This paper sets out a framework for reaching preliminary siting of tidal devices, drawing from case studies from three locations in the US where research studies have provided information in support of tidal deployments. \u0000Through the TEAMER funding opportunity in the US, tidal energy device and project developers were able to engage US Department of Energy national laboratory scientists and engineers to provide technical assistance for investigating potential tidal deployment sites within US waters. The bodies of water of interest had already been determined by the proponents at the start of the project and constraints and opportunities within those bodies of water were examined to optimize siting capabilities for the developers. Using numerical models and field observations, we characterized tidal resources at a scale that will allow for optimization of energy extraction. We examined the natural and human infrastructure constraints for deploying and operating tidal devices and arrays including channel widths, bathymetry, vessel traffic, ferry lanes, and grid interconnects, in order to narrow siting options. We also examined the biological resources in the water bodies of interest, with a focus on populations of endangered marine mammals and fish, and the critical habitats that support them. The biological resources were then related to the applicable regulatory requirements in place in US for federal and state statutes in areas where the tidal applicants wish to deploy. Based on these analyses, preferred deployment locations were delineated and processes for meeting regulatory requirements laid out, including post-installation monitoring plans that will be needed. This initial assessment of logistical, regulatory, and environmental conditions for the deployment of a tidal technology is a first step toward the achievement of regulatory compliance for tidal energy projects. \u0000Three locations were considered for tidal energy development in the US. The first one included the area around an archipelago of islands in the northern portion of Washington State, near the US-Canada border, with the intent of installing one or more floating tidal devices to add energy resilience and independence for the single utility that services the isolated islands. The second location was in the coastal waters of Maine where tidal power would be added to the local electrical grid. The third location was in Cook Inlet, Alaska, where the applicant seeks to deploy multiple floating tidal devices to provide renewable energy in place of conventionally generated power for the city of Anchorage.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132101741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Operating and Extreme weather conditions for testing Offshore Devices at Marine Renewable Energy Lab (MaRELab)","authors":"P. Contestabile, Sara Russo, A. Azzellino, F. Cascetta, D. Vicinanza","doi":"10.36688/ewtec-2023-558","DOIUrl":"https://doi.org/10.36688/ewtec-2023-558","url":null,"abstract":"Marine Renewable Energy Lab (MaRELab) is an onshore/offshore infrastructure for testing full and model scale prototypes aimed at harvesting energy from marine renewable sources.It is a real environment testing site located in the port of Naples, in proximity of the final part of San Vincenzo artificial breakwater. The laboratory covers an area of about 4 km2, including 40 meters along the breakwater, and moving 200 meters in the seaside from this. Just few meters from the breakwater, it is possible to reach about 30 meters deep, allowing the correct scaling of the behavior of platforms in deep and intermediate waters. Due to its facilities, MaRELab enables to test different kind of devices. On the breakwater area for example is currently installed the OBREC device (Overtopping BReakwater for Energy Conversion), that exploits the overtopping phenomenon in order to produce energy. In the sea area, instead, floating wind turbines with scaling up till 1:7 approximatively can be installed. Furthermore, other floating devices, such as solar islands, innovative breakwater, can be tested, both individually or combined.The opportunity of investigating these technologies in a real environment allows to evaluate the effective dynamic, structural and energy performances, as well as the effective resistance of materials. Moreover, some physical phenomena are clarified due to higher scaling with respect to indoor laboratory tests. The optimal testing of the different technologies requires an extensive knowledge of the meteorological and marine conditions at the pilot site. For this purpose, in this work, wind and wave energy resources are assessed. In particular, wind and wave hourly data from re-analysis ERA5 dataset (ECMWF) are considered. Data cover the period 1979-2020 and are available for fixed geographical points. In order to characterize more in detail nearshore conditions, wave data have been propagated through the software MIKE21 SW.The energy resource assessment represents a practical guide in defining the optimal testing conditions. It provides information on the distribution of wind and wave energy resources at MaRELab during the year. Moreover, it is possible to investigate the correlation of the two resources [1]. The characterization of the site and the knowledge of the technology to be tested, suggest when the optimal meteorological and marine condition occurs. An Extreme Value Analysis has been carried out to define extreme wave conditions with several return period [2]. Operational and extreme condition, depending on the scaling of the devices, can thereby be realized. \u0000REFERENCES \u00001.        Contestabile, P., Russo, S., Azzellino, A., Cascetta, F., Vicinanza, D. (2022).  \"Combination of local sea winds/land breezes and nearshore wave energy resource: Case study at MaRELab (Naples, Italy)\", Energy Conversion and Management, ISSN 0196-8904, 257, 115356, https://doi.org/10.1016/j.enconman.2022.115356     \u00002.       Dentale, F., Furcolo, P., Pugl","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132104058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Upsampling wave temporal resolution: Investigating wave parameters and the influence on WEC power performance","authors":"Hannah Mankle, Bryson Robertson, Bryony DuPont","doi":"10.36688/ewtec-2023-564","DOIUrl":"https://doi.org/10.36688/ewtec-2023-564","url":null,"abstract":"Power production of wave energy converters (WEC) predicted in the time domain utilize wave resource parameters and time-domain hydrodynamic model simulations of the WEC. While the hydrodynamic model provides high temporal resolution of power production (10’s of Hz), the wave resource parameters are often based on frequency-domain calculations with temporal resolution of 30 minutes to an hour. However, real ocean wave conditions vary on much shorter time scales. Relying on frequency-domain calculations will not be sufficient to capture the short-term variability and accurately predict WEC power production for a standardized methodology that follows power system requirements. These requirements need forecasted data with high sampling frequency for accurate energy predictions. Looking specifically at resource characterization, high temporal resolution datasets are not publicly available or do not exist for many coastal locations. Due to data availability, low temporal resolution datasets are being used in a majority of studies to generate representative wave conditions as inputs to numerical simulations. Representative wave conditions are used to generate wave spectrums. The issue with this practice is spectrums are then used to predict the efficiency of systems that will not accurately capture the variability of waves in short timeframes. Creating a standardized methodology to increase the temporal resolution of metaocean conditions to inform model development can provide better forecasting of power production. Random amplitude, Fourier coefficient methods have been suggested for WEC simulations of finite durations to improve the observed variability in wave heights and power production. Variability using this method does increase for finite durations compared to the commonly used deterministic amplitude method. In this paper we will investigate the influence of wave parameters (significant wave height, maximum wave height, and energy period) on the prediction of WEC power production. A better understanding of the influence of these parameters will provide a path towards future standardization methodology for resource inputs for time-domain modeling.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132234399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Laboratory Tests Assessment of a Mechanical Sensor-less MPPT Control Strategy for Tidal Turbines","authors":"Mohammad Rafiei, Francesco Salvatore, Carwyn Frost, Ian Benson","doi":"10.36688/ewtec-2023-434","DOIUrl":"https://doi.org/10.36688/ewtec-2023-434","url":null,"abstract":"The purpose of this study is to demonstrate through towing tank experiments the effectiveness of a novel sensor-less Maximum Power Point Tracking (MPPT) control for Tidal Stream Turbines (TST) under fluctuations of the onset flow.\u0000 \u0000Ocean energies will play a crucial role in the renewable energy sector over the next decades. Instream turbines for tidal currents are a rapidly maturing technology to exploit a highly predictable energy source. However, short-term fluctuations on the inflow velocity caused by waves or turbulence determine fatigue loads that affect system reliability. Power control strategies to maximize the energy yield can be also used to mitigate the effects of transient loading on drivetrain components.\u0000Aim of this paper is to present a straightforward and robust MPPT control method based on the linear relationship between the current and voltage squared of the generator's DC outputs. The method requires pre-determined turbine characteristics to establish the control reference that is effective across operating conditions. The proposed MPPT model was derived mathematically through linearization and simplifications of the turbine power conversion system and validated by model tests carried out in the wave-towing tank facility of CNR-INM in Rome, Italy, using the 1.5 m diameter Tidal Turbine Testing (TTT) device developed at the Queen’s University Belfast (QUB).\u0000 \u0000In the study, a conventional TSR control method was also considered in order to perform a comparative analysis of system response to inflow speed fluctuations with time scales comparable to turbine revolution periods. TSR control was tested using two control references: TSR = 5 (design point) and TSR = 6 (over-speed zone) to verify the operation of the turbine under different loading conditions. The tests were conducted in two scenarios: calm water (steady state) and unsteady inflow with a regular (sinusoidal or monochromatic) waveform, with amplitude chosen to simulate an extreme wave case.\u0000The power output was measured from the turbine during regular wave conditions and compared to results from steady flow to assess the impact of wave-induced velocity on turbine performance (Fig. 1). Test results showed that by using the proposed MPPT control strategy, the algorithms converged to the maximum power coefficient (Fig. 2), which validates the proposed methodology. Results also demonstrated the capability of the proposed MPPT to significantly reduce mechanical loads fluctuations as compared to the TSR control.\u0000In the full-length paper, the proposed MPPT control strategy is outlined, the test methodology, set-up and conditions are described, and main results are presented and discussed.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134102995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tidal Turbine Benchmarking Project: Stage I - Steady Flow Blind Predictions","authors":"R. Willden, Xiaosheng Chen, C.R. Vogel","doi":"10.36688/ewtec-2023-574","DOIUrl":"https://doi.org/10.36688/ewtec-2023-574","url":null,"abstract":"This paper presents the first blind prediction stage of the Tidal Turbine Benchmarking Project being conducted and funded by the UK's EPSRC and Supergen ORE Hub. In this first stage, only steady flow conditions, at low and elevated turbulence (3.1%) levels, were considered. Prior to the blind prediction stage, a large laboratory scale experiment was conducted in which a highly instrumented 1.6m diameter tidal rotor was towed through a large towing tank in well-defined flow conditions with and without an upstream turbulence grid.\u0000Details of the test campaign and rotor design were released as part of this community blind prediction exercise. Participants were invited to use a range of engineering modelling approaches to simulate the performance and loads of the turbine. 26 submissions were received from 12 groups from across academia and industry using solution techniques ranging from blade resolved computational fluid dynamics through actuator line, boundary integral element methods, vortex methods to engineering Blade Element Momentum methods.\u0000The comparisons between experiments and blind predictions were extremely positive helping to provide validation and uncertainty estimates for the models, but also validating the experimental tests themselves. The exercise demonstrated that the experimental turbine data provides a robust data set against which researchers and design engineers can test their models and implementations to ensure robustness in their processes, helping to reduce uncertainty and provide increased confidence in engineering processes. Furthermore, the data set provides the basis by which modellers can evaluate and refine approaches.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"666 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134505924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wave Amplification inside an Open Circular Caisson for Wave Energy Conversion in Waters with Medium Energy Density","authors":"Jiahn-Horng Chen","doi":"10.36688/ewtec-2023-164","DOIUrl":"https://doi.org/10.36688/ewtec-2023-164","url":null,"abstract":"Wave energy is one of important marine renewable energy resources. Many studies have been devoted to harnessing the energy for human use. Though they are almost everywhere in the sea, waves can be much more significant in some sea areas than others. For example, the wave energy density in Asian waters is usually much less than that in European west coasts. \u0000To make the wave energy harvesting more viable in Asian waters with medium wave energy density, we propose to employ an open caisson to amplify the wave locally and to combine it with a wave energy converter to tap the amplified wave energy. In this study, we focus on the effect of incident wave height on the amplification factor which is defined as the ratio of the wave height inside the caisson to that of the incident wave. Shown in Figure 1, the caisson is mounted vertically on the horizontal seabed in the open sea. At the edge of the opening, it has two guides on the two sides of the opening. They are identical in geometry and part of a solid cylinder. The purpose of the two guides is to enhance the wave amplification inside the caisson. \u0000The study was conducted primarily by CFD computations and partially verified by experiments. In computations, the finite volume method was employed to discretize the Navier-Stokes equations. A multi-block grid was generated for computational purposes. The volume-of-fluid (VOF) method was used to capture the free surface. The nonlinear iterations were conducted with the PISO method. And the implicit time marching scheme was adopted in the time direction. It is interesting to find that the amplified wave height in the caisson is not linearly related to the incident wave height. Furthermore, the amplification factor is also a function of the incident wave period. The wave period at which the peak value of the amplification factor appears is insensitive to the wave height. The amplification factor is usually greater than unity for a wide range of incident wave period.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134504425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dimensioning and optimization of multi-source offshore renewable energy parks","authors":"Anton Schaap, Hinne van der Zant","doi":"10.36688/ewtec-2023-552","DOIUrl":"https://doi.org/10.36688/ewtec-2023-552","url":null,"abstract":"Multi-source offshore renewable energy parks, consisting of wind, solar and wave converters, can utilize the available offshore area much more efficiently than single source wind parks. They can also produce power with a higher capacity factor than single source parks, utilizing the available grid connection more efficiently. Dimensioning and financial optimization of such parks will be driven by geographic constraints like available area, water depths, shipping lanes, exclusion zones etc., but also by the available resources of wind, solar and wave power. Another major driver in the optimization will be the electricity price. With the raising share of weather dependent renewables in the electricity mix, the electricity price will become more volatile. Therefore, an optimized design process of a multi-source park should also incorporate a pricing mechanism that can produce hourly electricity prices based on actual weather conditions. The paper will present the results of a numerical model that can integrate solar and wave power in a wind park area as well as optimize the export cable capacity. Battery storage can be added to this multi-source park to shift part of the production to hours with higher electricity prices. A case study has been performed for the planned offshore wind park TNW, North of the Dutch  Waddeneilanden. Since such a multi-source park will have an expected lifetime of about 30 years, it will even reach the year 2050, in which weather dependent renewable energy will be much more dominant than today, with far stronger electricity price volatility. For the electricity price calculation, assumptions are made for the installed base of solar, wind and wave power in the whole of The Netherlands, as well as the geographic spread of this installed base over the land area and the offshore exclusive economic zone in the North Sea. This installed base is simplified by concentrating it in about ten locations divided over this area. Other necessary assumptions are the future electricity demand pattern, the future capacity of the interconnections with the surrounding countries and the capacity of the flexible load that will be available at that time (electric cars, electric heaters etc.). From literature, the cost of conventional power fueled by natural gas and/or hydrogen is derived which serves as back up power for hours with low wind, solar and wave power production. Based on all these assumptions, a pricing curve is constructed reaching from sub zero at abundant renewable supply to a maximum value at zero renewable supply. With the model, scenarios of future developments in installed wind, solar and wave power, but also in e.g. electric cars, electric heaters and other flexible loads, can be examined and the sensitivity of the optimization of the multi-source park design can be determined. The relevance of wave power can be determined from the average price per MWh that wave power can earn compared to wind and solar.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133714239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Designing Vortex Generators for Tidal Turbine Blades","authors":"M. Manolesos, Nicholas Kaufmann, George Papadakis","doi":"10.36688/ewtec-2023-343","DOIUrl":"https://doi.org/10.36688/ewtec-2023-343","url":null,"abstract":"Increasing tidal turbine performance through innovation is crucial if the cost of tidal energy is to become competitive compared to other sources of energy. The present investigation deals with the application of Vortex Generators (VGs) on tidal turbines in view of increasing their performance. The more mature wind energy industry uses passive VGs either as a retrofit or in the blade design process to reduce separation at the inboard part of wind turbine blades. Tidal turbine blades also experience flow separation and here we examine whether passive vane VGs can be used to reduce or suppress that separated flow. \u0000Vortex generators (VGs) in various forms have been used and studied for flow separation control on wings since the 1940s [1]. Their working principle is relatively simple: they generate streamwise vortices that energise the boundary layer on the surface they are attached to, by bringing high momentum fluid closer to the surface [2]. This mechanism has been described by various researchers [3–6], while a number of studies have provided optimization guidelines under a variety of flow conditions [7–13]. \u0000In the present investigation, a VG configuration is selected following a thorough wind tunnel campaign. It is found that sizing parameters for the tidal turbine profile are very similar to the wind turbine relevant literature [13,14]. The best performing vane VG configuration had a height of 0.007c, which corresponded to half the local boundary layer height (0.5δ) for operational Reynolds numbers. The results are also used to validate a Reynolds Averaged Navier Stokes (RANS) VG modelling approach using the BAY model [15]. The validated method is used to simulate the flow past a tidal turbine in both model size (1:8) and full scale, see Figure 1. The results show that VGs do suppress flow separation in both cases. However, and importantly, it is revealed that the significance of rotational effects is such that when deciding VG placement locations, only the full size blade should be considered. In the interest of brevity, the performance increase caused by a standard VG configuration is show in Figure 2, where a power coefficient improvement of 1.05% is predicted at λ=3. Figure 3 shows the effect on the normal and tangential forces on the blade. In the final paper and presentation, the results for different VG locations will be included and analysed in detail.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129101663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental passive and reactive control of a Laboratory Scale WEC Point Absorber","authors":"Bret Bosma, Courtney Beringer, Bryson Robertson","doi":"10.36688/ewtec-2023-184","DOIUrl":"https://doi.org/10.36688/ewtec-2023-184","url":null,"abstract":"Scaled testing is an important and valuable step in the process of determining best practices of WEC development, validating numerical models of WEC systems, and/or preparing for larger scale testing. Validation and verification of numerical models are very important as there are physical phenomena that are hard to numerically model such as non-linear frictional effects. This paper builds on the 2021 EWTEC paper [1] in performing and evaluating experimental testing of the Laboratory Upgrade Point Absorber (LUPA). Since this last paper, LUPA has been fabricated and deployed and an initial characterization has been performed. Particularly passive (damping), and reactive (damping and stiffness) control methodologies are employed in regular waves to characterize and evaluate the mechanical power extracted from the waves. Reactive control allows us to invest energyin the system to get a greater average energy out as compared to damping control. \u0000The LUPA project has just finished its first deployment in the Large Wave Flume at the O.H. Hinsdale Wave Research Laboratory at Oregon State University as shown in Figure 1. Three modes of operation were tested, namely one body heave only, two body heave only, and six degrees of freedom. The one body heave only mode restricts the motion to linear and vertical and fixes the spar body so that the float is the only body free to move. The two body heave only maintains the vertical linear motion, but unlocks the float such that the float and spar are free to heave. The six degrees of freedom case is a floating moored mode with no restrictions on motion. \u0000This paper will focus on comparing passive and reactive control for the one body heave only case and the six degreesof freedom case with preliminary results shown in Figure 2. Regular waves were tested, focusing on a single wave heightand sweeping the wave period. Results will be presented in power (W) units and in capture width (m). Fig. 2. Top shows max power output vs input wave period for one body and two body configurations and just damping and damping and stiffness cases.Take note of differing input wave height. Bottom shows capture width. \u0000The LUPA project will provide a valuable testing platform for students and researchers. It will also provide a publicly available open source design and dataset for the research community here: https://github.com/PMECOSU/LUPA. This paper will serve as documentation of the initial testing of the system, providing baseline control results to be compared in future testing.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129117715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}