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Journal articles on the topic 'OWC'
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1
Amalia, Ghina, Utari Sriwijaya Minaka, and Aprilianda Aprilianda. "Karakteristik Parameter Kuat Geser Tanah pada Lereng Akibat Perubahan Kadar Air Tanah." Jurnal Teknik Sipil 21, no. 1 (2025): 174–88. https://doi.org/10.28932/jts.v21i1.7509.
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Longsoran yang terjadi pada lereng diindikasikan disebabkan oleh peningkatan massa tanah akibat bertambahnya kadar air yang mengisi pori-pori tanah yang akan memengaruhi sifat-sifat tanah terutama kuat geser sebagai salah satu sifat mekanis tanah. Penelitian ini bertujuan untuk menganalisis pengaruh perubahan kadar air tanah terhadap kuat geser tanah pada lereng. Penelitian menggunakan sampel tanah terganggu yang diambil pada pinggiran lereng di Ruas Jalan Manna-Pagaralam dan telah dikeringkan. Pengujian pemadatan dilakukan untuk mendapatkan nilai kadar air optimum (OWC) yang akan merepresentasikan nilai tengah dari variasi kadar air tanah pada sampel uji. Variasi sampel uji di antaranya OWC-20%OWC, OWC-10%OWC, OWC, OWC+10%OMC, dan OWC+20%OWC. Kuat geser tanah didapatkan dengan pengujian Direct Shear. Menurut standar USCS tanah diklasifikasikan sebagai tanah lempung berpasir. Hasil pengujian Direct shear didapatkan nilai kohesi (c) tertinggi pada variasi OWC atau pada variasi kadar air optimum yaitu 2,796 kPa. Hal ini dikarenakan nilai kohesi terjadi pada bagian butiran halus yaitu lempung yang dipengaruhi oleh kandungan air antar butiran. Sedangkan nilai sudut geser dalam tertinggi didapatkan pada variasi OWC-10%OWC sebesar 32,15o hal ini dikarenakan nilai sudut geser dalam terjadi pada bagian butiran kasar yaitu butiran pasir dimana gesekan akan berkurang seiring dengan bertambahnya kandungan air yang mengisi pori-pori tanah.
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Simonetti, Irene, Andrea Esposito, and Lorenzo Cappietti. "Experimental Proof-of-Concept of a Hybrid Wave Energy Converter Based on Oscillating Water Column and Overtopping Mechanisms." Energies 15, no. 21 (2022): 8065. http://dx.doi.org/10.3390/en15218065.
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This paper presents the results of laboratory tests on a hybrid wave energy converter concept, the O2WC (Oscillating-Overtopping Water Column) device. The proposed device aims at providing an alternative to the classical OWC concept, storing part of the wave energy of the highly energetic sea states in a second chamber at atmospheric pressure, through overtopping phenomena. In this way, the maximum airflow rate and air pressure in the OWC chamber are reduced, possibly aiding the safe functioning of the air turbine, and allowing to exploit the excess of energy instead of dissipating it through by-pass valves. The performance of the device is investigated under different incident wave conditions, for different design parameters. The height of the overtopping threshold from the second chamber of the device which allows to maximize the performance has been selected. Results show that the decrease of the primary conversion efficiency of the OWC component of the device caused by the decreased air pressure in the OWC chamber can be partially compensated by the additional energy stored in the overtopping chamber of the O2WC device. Overall, the studied O2WC device has capture width ratio values ranging between 0.3 and 0.7.
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Elleithy, Wael, Chin Chee Fung, Jayaprakash Jaganathan, Teck Leong Lau, and Mohammed Parvez Anwar. "Effect of Curing Method on Concrete with Palm Oil Fuel Ash as a Cement Replacement." International Journal of Engineering & Technology 7, no. 3.36 (2018): 68. http://dx.doi.org/10.14419/ijet.v7i3.36.29081.
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In this paper, the effect of different curing methods on the strength of concrete with palm oil fuel ash as a cement replacement is investigated. An experimental program was carried out to study the effect of five different curing methods, i.e., water curing (WC), air curing (AC), plastic-wrapped curing (PC), oven and water curing (OWC), and oven and air curing (OAC), on the compressive and flexural strengths of palm oil fuel ash concrete (POFA20), where 20% of the cement was replaced by palm oil fuel ash. The results obtained from this investigation showed that POFA20-WC has the highest compressive and flexural strength, whilst POFA20-AC has the lowest at the age of 28 days. Both of the POFA20-OWC and POFA20-OAC have the highest compressive and flexural strength at the age of 3 days. The results emphasize the positive effect of oven curing procedure to achieve high compressive and flexural strength at early stage. However, the rate of hydration started to decrease at later stages, which leads to much lower rate of gaining strength in POFA20-OWC and POFA20-OAC. Water curing method is thus recommended in the construction industry except for extraordinary requirements and/or circumstances.
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Kurniadi, S., and Sutardi. "Numerical Study of Conventional Oscillating Water Column and Oscillating Water Column Using Helmholtz Resonator on Non-Linear Wave Input with Sloshing Characteristics." Journal of Physics: Conference Series 2942, no. 1 (2025): 012011. https://doi.org/10.1088/1742-6596/2942/1/012011.
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Abstract One of the latest OWC concepts that is expected to improve OWC performance and lessen the sloshing phenomenon is the Helmholtz resonator OWC. This study uses the Reynold Averaged Navier-Stokes (RANS) based CFD method with the k-ω SST turbulence model. 2D modeling is performed under transient conditions by applying the Volume of Fluid (VoF) technique to model the sloshing phenomenon in the OWC. According to the simulation result on input waves with sloshing characteristics (T = 1.08 s, H = 0.13 m, H/L = 0.073) the Helmholtz resonator OWC (Sc = 0.05 m, e = 0.01 m, e = 0.05 m) produces better performance with ξ by 17%, Cr by 7% and is able to prevent energy loss (Cd ) up to 9.4% compared to the conventional OWC (Sc = 0.05 m, e = 0.05 m, e = 0.01 m). From the results of the OWC airspace velocity contours, it is found that the conventional OWC has a larger and faster vortex shedding than the Helmholtz resonator OWC. In this case, the Helmholtz resonator OWC in waves with sloshing characteristics can reduce the effect of turbulence-shedding vortex caused by waves with sloshing characteristics much better than the OWC.
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Cahyadi, Willy Anugrah, Yeon Ho Chung, Zabih Ghassemlooy, and Navid Bani Hassan. "Optical Camera Communications: Principles, Modulations, Potential and Challenges." Electronics 9, no. 9 (2020): 1339. http://dx.doi.org/10.3390/electronics9091339.
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Optical wireless communications (OWC) are emerging as cost-effective and practical solutions to the congested radio frequency-based wireless technologies. As part of OWC, optical camera communications (OCC) have become very attractive, considering recent developments in cameras and the use of fitted cameras in smart devices. OCC together with visible light communications (VLC) is considered within the framework of the IEEE 802.15.7m standardization. OCCs based on both organic and inorganic light sources as well as cameras are being considered for low-rate transmissions and localization in indoor as well as outdoor short-range applications and within the framework of the IEEE 802.15.7m standardization together with VLC. This paper introduces the underlying principles of OCC and gives a comprehensive overview of this emerging technology with recent standardization activities in OCC. It also outlines the key technical issues such as mobility, coverage, interference, performance enhancement, etc. Future research directions and open issues are also presented.
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Boccotti, Paolo. "Comparison between a U-OWC and a conventional OWC." Ocean Engineering 34, no. 5-6 (2007): 799–805. http://dx.doi.org/10.1016/j.oceaneng.2006.04.005.
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Yang, Hyunjai, Hyen-Cheol Jung, and WeonCheol Koo. "Oscillating Water Column (OWC) Wave Energy Converter Part 1: Fixed OWC." Journal of Ocean Engineering and Technology 36, no. 4 (2022): 280–94. http://dx.doi.org/10.26748/ksoe.2022.009.
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<i>This study reviews the recent development and research results of a fixed oscillating water column (OWC) wave energy converter (WEC). The OWC WEC can be divided into fixed and floating types based on the installation location and movement of the structure. In this article, the study on a stationary OWC WEC, which is close to commercialization through the accumulation of long-term research achievements, is divided into five research categories with a focus on primary energy conversion research. These research categories include potential-flow-based numerical analysis, wave tank experiments, computational fluid dynamics analyses toward investigation of fluid viscous effects, U-shaped OWC studies that can amplify water surface displacement in the OWC chamber, and studies on OWC prototypes that have been installed and operated in real sea environments. This review will provide an overview of recent research on the stationary OWC WEC and basic information for further detailed studies on the OWC.</i>
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Mayon, Robert, De-zhi Ning, Chong-wei Zhang, and Lars Johanning. "Hydrodynamic Performance of A Porous-Type Land-Fixed Oscillating Water Column Wave Energy Converter." China Ocean Engineering 36, no. 1 (2022): 1–14. http://dx.doi.org/10.1007/s13344-022-0008-9.
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AbstractA hybrid, porous breakwater—Oscillating Water Column (OWC) Wave Energy Converter (WEC) system is put forward and its hydrodynamic performance is investigated using the fully nonlinear, open-source computational fluid dynamics (CFD) model, OpenFOAM. The permeable structure is positioned at the weather side of the OWC device and adjoined to its front wall. A numerical modelling approach is employed in which the interstices within the porous structure are explicitly defined. This permits the flow field development within the porous structure and at the OWC front wall to be observed. The WEC device is defined as a land-fixed, semi-submerged OWC chamber. A range of regular incident waves are generated at the inlet within the numerical tank. The OWC efficiency and the forces on the structure are examined. Results are compared for the simulation cases in which the porous component is present or absent in front of the OWC chamber. It is found that the incorporation of the porous component has minimal effect on the hydrodynamic efficiency of the OWC, reducing the efficiency by less than 5%. Nevertheless, the forces on the front wall of the OWC can be reduced by up to 20% at the higher wave steepness investigated, through inclusion of the porous structure at the OWC front wall. These findings have considerable implications for the design of hybrid OWC—breakwater systems, most importantly in terms of enhancing the durability and survivability of OWC WECs without significant loss of operational efficiency.
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Sheng, Wanan, and George Aggidis. "An Experimental Study of a Conventional Cylindrical Oscillating Water Column Wave Energy Converter: Fixed and Floating Devices." Energies 18, no. 3 (2025): 500. https://doi.org/10.3390/en18030500.
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Oscillating water column (OWC) wave energy converters (WECs) are very popular types of wave energy converters due to their practical implementations, their versatility in deployment in different marine environments, and their high reliability in wave energy conversion. In development, different forms of OWCs have been proposed and advanced, such as fixed OWCs (on the shoreline, on breakwaters, or bottom standing) and floating OWCs (the spar and the backward-bent duct buoy, BBDB). In reality, a special type of OWC, the cylindrical OWC, is the simplest OWC in terms of its structural design and possible analytical/numerical solutions. However, such a simple OWC has not seen any practical applications because a cylindrical OWC is inefficient in wave energy absorption when compared to other types of OWC WECs. To study the simplest cylindric OWC, an experiment was carried out in a wave tank, and the relevant results are presented in this paper, with the aims of (i) analyzing the experimental data and exploring why such an OWC is inefficient in terms of wave energy absorption; (ii) providing experimental data for those who want experimental data to validate their numerical models; and (iii) establishing a baseline model so that comparisons can be made for improvements to the simple cylindrical OWC. As an example, an innovative solution was applied to the simple OWC such that its hydrodynamics and energy extraction performance can be significantly improved (the corresponding results will be presented in a separate paper).
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Mia, Mohammad Rashed, Ming Zhao, Helen Wu, Vatsal Dhamelia, and Pan Hu. "Hydrodynamic Performance of a Floating Offshore Oscillating Water Column Wave Energy Converter." Journal of Marine Science and Engineering 10, no. 10 (2022): 1551. http://dx.doi.org/10.3390/jmse10101551.
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A floating oscillating water column (OWC) wave energy converter (WEC) supported by mooring lines can be modelled as an elastically supported OWC. The main objective of this paper is to investigate the effects of the frequency ratio on the performance of floating OWC (oscillating water column) devices that oscillate either vertically or horizontally at two different mass ratios (m = 2 and 3) through two-dimensional computational fluid dynamics simulations. The frequency ratio is the ratio of the natural frequency of the system to the wave frequency. Simulations are conducted for nine frequency ratios in the range between 1 and 10. The hydrodynamic efficiency achieves its maximum at the smallest frequency ratio of 1 if the OWC oscillates horizontally and at the largest frequency ratio of 10 if the OWC oscillates vertically. The frequency ratio affects the hydraulic efficiency of the vertical oscillating OWC significantly stronger than that of the horizontal oscillating OWC, especially when it is small. The air pressure and the volume oscillation in OWC is not affected much by the horizontal motion of the OWC but is significantly affected by the vertical motion, especially at small frequency ratios.
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Kisacik, Dogan, Vasiliki Stratigaki, Minghao Wu, et al. "Efficiency and Survivability of a Floating Oscillating Water Column Wave Energy Converter Moored to the Seabed: An Overview of the EsflOWC MaRINET2 Database." Water 12, no. 4 (2020): 992. http://dx.doi.org/10.3390/w12040992.
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Floating oscillating water column (OWC) type wave energy converters (WECs), compared to fixed OWC WECs that are installed near the coastline, can be more effective as they are subject to offshore waves before the occurrence of wave dissipation at a nearshore location. The performance of floating OWC WECs has been widely studied using both numerical and experimental methods. However, due to the complexity of fluid–structure interaction of floating OWC WECs, most of the available studies focus on 2D problems with WEC models of limited degrees-of-freedom (DOF) of motion, while 3D mooring effects and multiple-DOF OWC WECs have not been extensively investigated yet under 2D and 3D wave conditions. Therefore, in order to gain a deeper insight into these problems, the present study focuses on wave flume experiments to investigate the motion and mooring performance of a scaled floating OWC WEC model under 2D wave conditions. As a preparatory phase for the present MaRINET2 EsflOWC (efficiency and survivability of floating OWC) project completed at the end of 2017, experiments were also carried out in advance in the large wave flume of Ghent University. The following data were obtained during these experimental campaigns: multiple-DOF OWC WEC motions, mooring line tensions, free surface elevations throughout the wave flume, close to and inside the OWC WEC, change in the air pressure inside the OWC WEC chamber and velocity of the airflow through the vent on top of the model. The tested wave conditions mostly include nonlinear intermediate regular waves. The data obtained at the wave flume of Ghent University, together with the data from the EsflOWC tests at the wave flume of LABIMA, University of Florence, provide a database for numerical validation of research on floating OWC WECs and floating OWC WEC farms or arrays used by researchers worldwide.
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Gayathri, R., Jen-Yi Chang, Chia-Cheng Tsai, and Tai-Wen Hsu. "Wave Energy Conversion through Oscillating Water Columns: A Review." Journal of Marine Science and Engineering 12, no. 2 (2024): 342. http://dx.doi.org/10.3390/jmse12020342.
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An oscillating water column (OWC) is designed for the extraction and conversion of wave energy into usable electrical power, rather than being a standalone renewable energy source. This review paper presents a comprehensive analysis of the mathematical modeling approaches employed in OWC systems, aiming to provide an in-depth understanding of the underlying principles and challenges associated with this innovative technology. A prominent classification within the realm of wave energy devices comprises OWC systems, which exhibit either fixed or floating configurations. OWC devices constitute a significant proportion of the wave energy converter prototypes currently operational offshore. Within an OWC system, a hollow structure, either permanently fixed or floating, extends below the water’s surface, creating an enclosed chamber where air is captured over the submerged inner free surface. This comprehensive study offers a thorough assessment of OWC technology in conjunction with air turbines. Additionally, the investigation delves into theoretical, computational, and experimental modeling techniques employed for analyzing OWC converters. Moreover, this review scrutinizes theoretical, computational, and experimental modeling methodologies, providing a holistic understanding of OWC converters. Ultimately, this work contributes a thorough assessment of OWC technology’s current state, accentuating its potential for efficient wave energy extraction and suggesting future research avenues.
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Xie, Guangci, Chao Hu, Dong Li, Yong Ma, Xu Zhang, and Yuanyao Zhu. "Hydrodynamic Performance Investigations of OWC and Hybrid System: Geometry of OWC and Rectangular Submerged Breakwater." Journal of Marine Science and Engineering 12, no. 12 (2024): 2191. https://doi.org/10.3390/jmse12122191.
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Due to its simplicity and high reliability, the Oscillating Water Column (OWC) has been a prominent focus of research. This study investigates the impact of OWC geometry on hydrodynamic performance by analyzing the effects of draft, chamber width, and Power Take Off (PTO) damping on energy conversion efficiency, reflection coefficient, transmission coefficient, and dissipation coefficient. The motion of the water column under different PTO damping conditions is analyzed. In addition, the hydrodynamic performance of the submerged breakwater-OWC hybrid system is studied and compared with that of a standalone OWC. The results show that a higher opening height improves the energy conversion efficiency of the OWC under medium-to-long waves. There is an optimal draft for the OWC to maximize the energy conversion efficiency for different wave periods. Meanwhile, the optimal draft increases with the wave period. Increasing PTO damping does not change the resonance period of the OWC, while the free surface elevation inside the chamber reduces. Within a range of periods around the maximum inclination, multi-point measurements of the wave elevation in the chamber are necessary to reduce measurement errors caused by the spatial non-uniformity of the water column. The submerged breakwater-OWC hybrid system exhibits a higher energy conversion efficiency under medium-to-long waves compared to a standalone OWC, and there is an optimal breakwater length.
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Wu, Minghao, Vasiliki Stratigaki, Peter Troch, et al. "Experimental Study of a Moored Floating Oscillating Water Column Wave-Energy Converter and of a Moored Cubic Box." Energies 12, no. 10 (2019): 1834. http://dx.doi.org/10.3390/en12101834.
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This paper describes experimental research on a floating moored Oscillating Water Column (OWC)-type Wave-Energy Converter (WEC) carried out in the wave flume of the Coastal Engineering Research Group of Ghent University. This research has been introduced to cover the existing data scarcity and knowledge gaps regarding response of moored floating OWC WECs. The obtained data will be available in the future for the validation of nonlinear numerical models. The experiment focuses on the assessment of the nonlinear motion and mooring-line response of a 1:25 floating moored OWC WEC model to regular waves. The OWC WEC model motion has 6 degrees of freedom and is limited by a symmetrical 4-point mooring system. The model is composed of a chamber with an orifice on top of it to simulate the power-take-off (PTO) system and the associated damping of the motion of the OWC WEC model. In the first place, the motion response in waves of the moored floating OWC WEC model is investigated and the water surface elevation in the OWC WEC chamber is measured. Secondly, two different mooring-line materials (iron chains and nylon ropes) are tested and the corresponding OWC WEC model motions and mooring-line tensions are measured. The performance of these two materials is similar in small-amplitude waves but different in large wave-amplitude conditions. Thirdly, the influence of different PTO conditions is investigated by varying the diameter of the top orifice of the OWC WEC model. The results show that the PTO damping does not affect the OWC WEC motion but has an impact on the water surface elevation inside the OWC chamber. In addition, an unbalanced mooring configuration is discussed. Finally, the obtained data for a moored cubic model in waves are presented, which is a benchmarking case for future validation purposes.
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Tang, Zhengjie, Runzhou Huang, Changtong Mei, et al. "Influence of Cellulose Nanoparticles on Rheological Behavior of Oil Well Cement-Water Slurries." Materials 12, no. 2 (2019): 291. http://dx.doi.org/10.3390/ma12020291.
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Performance of hardened oil well cement (OWC) is largely determined by the rheological properties of the cement slurries. This work was carried out to investigate the effect of water- to-cement ratio (WCR) and cellulose nanoparticles (CNPs), including cellulose nanofibers (CNFs) and cellulose nanocrystals (CNCs), on rheology performance of OWC-based slurries using a Couette rotational viscometer coupled with rheological models. The yield stress and viscosity of neat OWC slurries had a decreasing trend with the increase of WCRs. The suspension became increased unstable with the increase of WCRs. The properties of CNPs, including rheological behaviors, surface properties and morphology, determine the rheological performance of CNP-OWC slurries. In comparison with CNC-OWC slurries, the gel strength, yield stress and viscosity of CNF-OWC slurries were higher as CNFs were more likely to form an entangled network. The gel strength, yield stress and viscosity of CNP-OWC slurries increased with reduced CNF size through regrinding and the proportion of CNFs in the mixture of CNFs and CNCs, respectively.
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Tsai, Ching-Piao, Ching-En Huang, Chun-Han Ko, and Ying-Chi Chen. "AN EXPERIMENTAL STUDY OF HYDRODYNAMICS OF OWC DEVICE EMBODYING IN CAISSON BREAKWATER." Coastal Engineering Proceedings, no. 36 (December 30, 2018): 30. http://dx.doi.org/10.9753/icce.v36.structures.30.
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It has currently become an important issue in searching for clean and sustainable renewable energy. Wave power is one of substantial renewable energies. The oscillating water column (OWC) device is the most extensively studies of wave energy converter and the largest number of prototypes so far deployed into the sea. The breakwater-integrated OWC has been constructed successfully in Sakata harbor in Japan, Mutriku port in Spain, and Civitavecchia harbor in Italy etc. The breakwater-integrated OWC has several advantages, especially much easier maintenance of the wave energy plant (Falcão and Henriques, 2016). However, the front wall of typical OWC device may be received large wave force when the storm waves impacted on it. This study proposed an improvement of a caisson type breakwater-integrated OWC device by installing a perforated front wall to reduce the wave impacting on the structure but also to promote the capture efficiency of the wave energy. This study reports the experimental results of both water and air flow characteristics inside the OWC chamber to demonstrate the hydrodynamic performance of the improved OWC device.
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Didier, Eric, and Paulo Roberto de Freitas Teixeira. "Performance of an Oscillating Water Column Wave Energy Converter Integrated with Three Types of Harbor Protection Structures." Defect and Diffusion Forum 427 (July 14, 2023): 63–73. http://dx.doi.org/10.4028/p-bl5v8v.
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Oscillating water column (OWC) wave energy converters can be integrated in harbor protection structures, such as vertical, rubble mound and piled breakwaters. The interaction between the incident wave and the structure, in which the OWC device is integrated, is significantly different, since the structure of the vertical breakwater is impermeable, while that of the rubble mound breakwater is porous. The performance of the OWC device for the three configurations is analyzed for a range of wave periods from 6 to 12 s and a wave height of 1 m. The OWC device integrated into the vertical breakwater shows the best performance (maximum mean pneumatic power of 70 kW), and the mean pneumatic power is globally 3 % higher than that of the OWC device integrated into the rubble mound breakwater (maximum mean pneumatic power of 67.4 kW). The performance of the OWC device integrated into the piled breakwater shows a similar trend to the OWC device integrated into the vertical breakwater for wave periods lower than 9 s, but it has a significant loss of performance for higher wave periods.
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Nguyen, Anh-Hang, Hyo-Sang Jeong, Hyungsik Shin, and Hyuk-Kee Sung. "Theoretical Study on Dual-Function Optical Phased Array of LiDAR and Optical Wireless Communication Based on Optically Injection-Locked Semiconductor Lasers." Photonics 10, no. 5 (2023): 498. http://dx.doi.org/10.3390/photonics10050498.
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Light detection and ranging (LiDAR) and optical wireless communication (OWC) are in high demand and rapidly developing owing to the explosive growth of smart systems that require automotive and mobile devices. Optical phased arrays (OPA) have become a key technology in LiDAR and OWC owing to their nonmechanical beam steering capabilities. However, using separate LiDAR and OWC platforms in one system creates problems, such as spectrum congestion, resource consumption, and high complexity. We propose a dual-function OPA that enables LiDAR and OWC to function on a single platform based on the simultaneous amplitude and phase modulation of optically injection-locked semiconductor lasers. We numerically demonstrated that the primary LiDAR and secondary OWC function simultaneously by independent control of the main and side lobes in the OPA signal. The variation in side lobe levels is controlled at 20 or 25 dB to realize low- and high-level data for OWC function as well as maintaining the main beam LiDAR function. We successfully achieved wide-opening eye patterns of 10 Gbps data transmission of the OWC operation.
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Mina, Beatrice, Giovanni Malara, Corrado Altomare, and Felice Arena. "SPH NUMERICAL MODELLING OF A U-OWC WAVE ENERGY CONVERTER." Coastal Engineering Proceedings, no. 38 (May 29, 2025): 27. https://doi.org/10.9753/icce.v38.waves.27.
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This paper presents numerical simulations of a U- Oscillating Water Column (U-OWC) wave energy converter excited by regular sea waves. This device is an OWC (oscillating water column) converter comprising a U- duct at the seafront. As for the OWC device, it exploits the water column oscillations for compressing and expanding the air chamber above the water column with the purpose of producing an air flow through the turbine connected to the air chamber. However, the U-OWC comprises also a U-duct at the seafront that allows the converter to reach resonance conditions with the sea waves. A U-OWC prototype was installed in the Civitavecchia harbor (Arena, et al. 2013). Herein, to model the U-OWC wave energy converter, Smoothing Particle Hydrodynamics (SPH) has been adopted and implemented through the DualSPHysics software (Dominguez et al., 2022).
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Ko, Chun-Han, Chun-Yu Fan, and Ching-Piao Tsai. "Experimental Investigation of Wave Pressure on Breakwater-Integrated Oscillating Water Column Devices with a Perforated Wall." Journal of Marine Science and Engineering 12, no. 10 (2024): 1782. http://dx.doi.org/10.3390/jmse12101782.
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This study investigates the wave pressure on an Oscillating Water Column (OWC) device, which features a perforated wall positioned in front of the OWC chamber and is integrated with a caisson breakwater. The perforated wall is designed to mitigate wave impacts on the OWC device under storm wave conditions. To achieve this, a series of laboratory experiments were conducted using a 1:25 scale model, considering both regular and irregular waves. Wave pressure measurements and analyses were performed on various configurations to assess the effects of the perforated wall on the wave pressure exerted against the front wall of the OWC chamber and the caisson breakwater. The results indicate that the perforated wall effectively reduces the amplitude of water column oscillations within the OWC chamber during storm conditions, thereby significantly reducing wave pressure on the OWC chamber wall by approximately 14% and on the breakwater by about 20.3%.
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Shivashankar, P. Madhumathy, and Kumar Hareesh. "Design of Optical Wireless Communication (OWC) Systems for High-Capacity Data Transmission." Recent Trends in Analog Design and Digital Devices 8, no. 1 (2025): 34–38. https://doi.org/10.5281/zenodo.14799506.
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<em>Optical Wireless Communication (OWC) is a cutting-edge technology that utilizes light to transmit data without the need for physical cables. OWC includes technologies such as Visible Light Communication (VLC), Infrared Communication (IRC), and Free-Space Optical (FSO) communication. This paper explores the design principles, key challenges, and recent advancements in OWC systems, with a particular focus on high-capacity data transmission. Factors such as signal attenuation, alignment precision, interference control, and system scalability are discussed. Furthermore, the paper explores the potential integration of OWC with 5G and IoT applications for next-generation communication networks. Advanced simulation results are presented to highlight the performance and future prospects of OWC systems.</em>
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Chaudhary, Sushank, Lunchakorn Wuttisittikulkij, Jamel Nebhen, Abhishek Sharma, Demostenes Zegarra Rodriguez, and Santosh Kumar. "Terabyte capacity-enabled (10 x 400 Gbps) Is-OWC system for long-haul communication by incorporating dual polarization quadrature phase shift key and mode division multiplexing scheme." PLOS ONE 17, no. 3 (2022): e0265044. http://dx.doi.org/10.1371/journal.pone.0265044.
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Inter-satellite optical wireless communication (Is-OWC) links can become promising solutions to realize the next-generation high-speed communication services. The operation of Global Navigation Satellite Systems can be improved with the use of Is-OWC links through ranging and communication services. However, the key challenge in Inter-satellite link (ISL) is its effective range which is limited due to pointing errors. In this work, we propose to develop a high-capacity and long-reach Is-OWC link by incorporating hybrid mode division multiplexing (MDM) and wavelength division multiplexing (WDM) schemes to transmit ten independent channels over 40000kms Is-OWC link. Each channel is capable of carrying 400Gbps data which is encoded by the dual polarization quadrature phase shift key technique with required signal to noise ratio (SNR) and received power. The proposed Is-OWC link satisfies the enhanced communication within Geostationary Earth Orbit (GEO) and Low Earth Orbit (LEO) satellites. The proposed Is-OWC is further evaluated under the impact of space turbulences, particularly transmitter and receiver pointing errors. The result reported that the proposed Is-OWC link can transmit 4Tbps data over 16000kms with the transmitter pointing error of 2μrad and receiver pointing error of 1μrad.
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Naik, Nikita, Siming Zheng, and Harekrushna Behera. "Role of dual breakwaters and trenches on efficiency of an oscillating water column." Physics of Fluids 35, no. 4 (2023): 047115. http://dx.doi.org/10.1063/5.0146004.
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In this paper, the effects of double-submerged breakwaters and trenches on the hydrodynamic performance of an oscillating water column (OWC) are investigated. The multi-domain boundary element method is used to tackle the physical problem of wave scattering and radiation from the device. The role of the height of the breakwaters, depth of the trenches, width of the breakwaters and trenches, spacing between the structures, length of the OWC chamber, and other wave and structural parameters is investigated on the efficiency of OWC. The study reveals that there is an oscillating pattern of the efficiency curve in the presence of single or double breakwater/trenches; this pattern is absent when the bottom is flat. Moreover, compared to single or no breakwaters/trenches, the occurrence of full OWC efficiency is higher in the presence of double breakwaters/trenches. Furthermore, the amplitude of the oscillating pattern in the efficiency curve increases with an increase in the height and depth of the breakwaters and trenches, respectively. For some particular wave and structural parameters, zero OWC efficiency occurs nearly [Formula: see text] within [Formula: see text] ( k0 wave number and h water depth). This zero efficiency moves toward small wave numbers as the spacing between OWC and rigid breakwater/trench increases. The radiation conductance of OWC decreases with an increase in the barrier height. The findings outline the structural criteria that can be employed to build and deploy an effective OWC device.
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Papafotiou, M., G. Kargas, and I. Lytra. "Olive-mill Waste Compost as a Growth Medium Component for Foliage Potted Plants." HortScience 40, no. 6 (2005): 1746–50. http://dx.doi.org/10.21273/hortsci.40.6.1746.
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Research was carried out to evaluate composted olive-mill waste as a peat substitute in foliage potted plant production. Rooted cuttings of Codiaeum variegatum (L.) A. Juss and Syngonium podophyllum Schott were grown for 5 months and Ficus benjamina L. for 10 months in media containing olive-mill waste compost (OWC), sphagnum peat and perlite in 1:3:4, 1:1:2, and 3:1:4 ratio (by volume), respectively, and their foliage and root growth was determined and compared to a control medium of 1 peat: 1 perlite (by volume). When up to 75% of peat in the control medium was replaced by OWC, C. variegatum foliage and root growth were similar compared with the control, while a 50% peat replacement gave the best growth. Syngonium podophyllum was more sensitive to peat replacement compared to C. variegatum, as only 25% of peat could be replaced by OWC without any reduction in foliage growth. The dry weight of the roots was not affected in all media tested. In F. benjamina, peat could be replaced up to 75% without effects on plant height and lateral shoot number, while the length of the laterals was progressively reduced with increasing OWC level. However, only at the highest OWC level (75% peat replacement) the laterals were shorter compared with the control. There was also a progressive reduction of main stem diameter, foliage fresh weight, and root dry weight with increasing OWC level in the medium. Even the lowest OWC level (25% peat replacement) caused a decrease of foliage and root weight compared with the control, with no effect though on plant visual quality. Even a 25% peat replacement by OWC caused an increase in bulk density. A considerable decrease of total porosity and readily available water were measured in media where 50% or 75% of peat was replaced by OWC. The pH of the medium with the highest OWC level was high during the first 4 months of culture compared to the other media. The electrical conductivity initially related to OWC level, but it decreased to values similar to that in the control medium during the first month of culture.
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Al Mudzakir, R. F., D. Satrio, R. W. Prastianto, and S. Rahmawati. "Oscillating water column supporting structures: A review." Journal of Physics: Conference Series 2828, no. 1 (2024): 012030. http://dx.doi.org/10.1088/1742-6596/2828/1/012030.
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Abstract Numerous studies on the potential for wave energy in Indonesian waters have been conducted using Wave Energy Converter (WEC). One of the most extensively studied and developed wave energy conversion technologies is the Oscillating Water Column (OWC). Although OWC technology has the good potential, there are still several difficulties and problems that prevent its widespread development and use. One is the difficulty of keeping the systems working in hostile marine conditions. The supporting structure is an integral part of the design and operation of an OWC system. An OWC system’s structural design must guarantee lifespan, stability, and dependability in a severe marine environment. More study is required to create durable and dependable systems, mainly supporting structures functioning in these conditions. This study reviews existing literature to analyse the structural strength of OWC systems, aiming to provide insights into methods for enhancing their durability and reliability, particularly in harsh marine conditions. Key findings include the classification of various supporting structure technologies used in OWC projects, providing insights into their effectiveness and applicability in different environmental settings. Moreover, the study emphasizes ongoing efforts to address obstacles limiting the widespread adoption of OWC technology, underscoring the need for further research and development.
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Sahoo, Gagan, Harekrushna Behera, and Tai-Wen Hsu. "Wave-Power Extraction by an Oscillating Water Column Device over a Step Bottom." Mathematics 13, no. 7 (2025): 1067. https://doi.org/10.3390/math13071067.
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This study investigates wave-power extraction by an oscillating water column (OWC) device over a porous-to-rigid step bottom using linearized water-wave theory. The interaction between water waves and the OWC device is analyzed by solving the governing boundary-value problem with the eigenfunction expansion method (EEM) and the boundary element method (BEM). The study examines the effects of key parameters, including the porous effect parameter of the bottom, OWC chamber width, and barrier height, on the device’s efficiency. The results indicate that the porous effect parameter significantly influences OWC performance, affecting resonance characteristics and efficiency oscillations. A wider OWC chamber enhances oscillatory efficiency patterns, leading to multiple peaks of full and zero efficiency. The efficiency shifts towards lower wavenumbers with increasing step depth and barrier height but becomes independent of these parameters at higher wavenumbers. Additionally, incident angle plays a crucial role, decreasing efficiency at lower angles and exhibiting oscillatory behavior at higher angles. Furthermore, susceptance and conductance follow an oscillatory pattern concerning the gap between the porous bottom and the OWC chamber as well as chamber width. The porous effect parameter strongly modulates these oscillations. The findings provide new insights for enhancing OWC efficiency with complex bottom topography.
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Heath, T. V. "A review of oscillating water columns." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 370, no. 1959 (2012): 235–45. http://dx.doi.org/10.1098/rsta.2011.0164.
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This paper considers the history of oscillating water column (OWC) systems from whistling buoys to grid-connected power generation systems. The power conversion from the wave resource through to electricity via pneumatic and shaft power is discussed in general terms and with specific reference to Voith Hydro Wavegen's land installed marine energy transformer (LIMPET) plant on the Scottish island of Islay and OWC breakwater systems. A report on the progress of other OWC systems and power take-off units under commercial development is given, and the particular challenges faced by OWC developers reviewed.
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Nuur Darmawan, Isra', Kholistianingsih Kholistianingsih, Fahmi Anas, and Asroful Abidin. "Analisis dan Simulasi PLTGL Model OWC menggunakan Ansys Fluent Studi Kasus Keefektifan Sistem dan Pengembangan di Pesisir Pantai Selatan Jawa Tengah." J-Proteksion: Jurnal Kajian Ilmiah dan Teknologi Teknik Mesin 9, no. 2 (2025): 112–21. https://doi.org/10.32528/jp.v9i2.2757.
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Pembangkit Listrik Tenaga Gelombang Laut (PLTGL) merupaakan teknologi yang mengubah energi kinetik gelombang laut menjadi energi listrik, dengan Oscillating Water Column (OWC) sebagai salah satu jenis yang umum digunakan. Penelitian ini bertujuan menganalisis dan mensimulasikan model OWC LIMPET single column menggunakan ANSYS FLUENT 2D dan data dari Pesisir Pantai Nusakambangan, Jawa Tengah tahun 2023. Penelitian ini menilai efektivitas sistem OWC dan potensi pengembangannya di daerah tersebut. Simulasi yang digunakan berupa simulasi CFD (Computational Fluid Dynamic) menggunakan software ANSYS FLUENT 2D untuk menghasilkan output kecepatan angin dari kolom. Model OWC disimulasikan dengan variasi output diameter kolom 90 cm, 80 cm, 60 cm, dan 40 cm. Daya yang dihasilkan dihitung dengan persamaan umum menghitung daya turbin angin dan selanjutya dianalisis potensi kelayakan ekonomi. Hasil penelitian menunjukkan bahwa output diameter kolom OWC 40 cm paling efektif, menghasilkan kecepatan angin rata-rata 3,08 m/s pada kondisi pasang surut dan gelombang maksimum. Total produksi energi mencapai 27.166,84 kWh/tahun. Proyek PLTGL-OWC di lokasi ini menunjukkan potensi kelayakan ekonomi dengan NPV sebesar Rp 1.644.961.729,51, IRR 17,91%, BCR 7,49, dan PP selama 3 tahun 4 bulan 10 hari.
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Weng, Huiyi, Wei Wang, Zhiwei Chen, Bowen Zhu, and Fan Li. "A Review of Indoor Optical Wireless Communication." Photonics 11, no. 8 (2024): 722. http://dx.doi.org/10.3390/photonics11080722.
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Indoor Optical Wireless Communication (OWC) provides a promising solution for high-capacity, low-latency, and electromagnetic interference-resistant wireless communication. Over the past decade, there has been extensive research addressing key challenges in indoor OWC. This article provides an overview of the current development status, key technologies, and challenges faced in the field of indoor OWC. Furthermore, at the end of this overview, an experimental demonstration of an indoor non-line-of-sight (NLOS) OWC system utilizing a spatial light modulator (SLM) for beam steering is demonstrated, which is expected to inspire research on related technologies.
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Gomes, Mateus das Neves, Eduardo Alves Amado, Elizaldo Domingues dos Santos, Liércio André Isoldi, and Luiz Alberto Oliveira Rocha. "Numerical Analysis of the Oscillating Water Column (OWC) Wave Energy Converter (WEC) Considering Different Incident Wave Height." Defect and Diffusion Forum 370 (January 2017): 120–29. http://dx.doi.org/10.4028/www.scientific.net/ddf.370.120.
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The ocean wave energy conversion into electricity has been increasingly researched in the last years. There are several proposed converters, among them the Oscillating Water Column (OWC) device has been widely studied. The present paper presents a two-dimensional numerical investigation about the fluid dynamics behavior of an OWC Wave Energy Converter (WEC) into electrical energy. The main goal of this work was to numerically analyze the optimized geometric shape obtained in previous work under incident waves with different heights. To do so, the OWC geometric shape was kept constant while the incident wave height was varied. For the numerical solution it was used the Computational Fluid Dynamic (CFD) commercial code FLUENT®, based on the Finite Volume Method (FVM). The multiphasic Volume of Fluid (VOF) model was applied to tackle with the water-air interaction. The computational domain is represented by the OWC device coupled with the wave tank. This work allowed to check the influence of the incident wave height on the hydropneumatic power and the amplification factor of the OWC converter. It was possible to identify that the amplification factor increases as the wave period increases, thereby improving the OWC performance. It is worth to highlight that in the real phenomenon the incident waves on the OWC device have periods, lengths and height variables.
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Romolo, Alessandra, Bruna Timpano, Valentina Laface, Vincenzo Fiamma, and Felice Arena. "Experimental Investigation of Wave Loads on U-OWC Breakwater." Journal of Marine Science and Engineering 11, no. 1 (2022): 19. http://dx.doi.org/10.3390/jmse11010019.
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A small-scale field experiment was conducted on a U-OWC incorporated into a caisson breakwater at the NOEL laboratory of Reggio Calabria (Italy). The U-Oscillating Water Column (U-OWC) or REWEC (REsonant Wave Energy Converter) is a device belonging to the family of OWCs. Such a device is very innovative, being able to absorb a very high percentage of incoming sea waves energy and to produce electrical power via proper PTO. The focus of the paper has been the analysis of the impact wave loads acting on the modified U-OWC structure during extreme wave events. A total of 250 records of pure wind waves were analyzed to verify the behaviors of wave loads acting on a U-OWC breakwater during operating conditions. The occurrence of both “quasi-standing wave” loads due to non-breaking waves and “impulsive wave loads”, exerted by a wave breaking against the U-OWC model, were observed. Then, Goda’s model was applied to predict the wave pressure distribution on the external wall of the U-OWC pneumatic chamber, and the theoretical results were compared to those obtained via small-scale field experiment.
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Cannata, Giovanni, Francesco Biondi, and Marco Simone. "Numerical Study on the Performance of an OWC under Breaking and Non-Breaking Waves." Journal of Marine Science and Engineering 12, no. 6 (2024): 936. http://dx.doi.org/10.3390/jmse12060936.
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A numerical model for the simulation of the performance of an oscillating water column (OWC) subjected to non-breaking and breaking waves is proposed in this paper. The numerical model consists of a hydrodynamic model specifically designed to simulate breaking waves and a pneumatic model that takes into account the air compressibility. The proposed numerical model was applied to evaluate the potential mean annual energy production from the waves of two coastal sites characterized by different hydrodynamic conditions: a deep-water condition, where the OWC interacts with non-breaking waves, and a shallow-water condition, where the OWC is subjected to breaking waves. The numerical results show that the effects of the air compressibility can be considered negligible only in numerical simulations of the performances of reduced-scale OWC devices, such as those used in laboratory experiments. We demonstrated that in real-scale simulations, the effect of the air compressibility within the OWC chamber significantly reduces its ability to extract energy from waves. The numerical results show that the effect of the air compressibility is even more significant in the case of a real-scale OWC located in the surf zone, where it interacts with breaking waves.
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Kurniawan, Aries Taufiq, Arief Budiman, Rachmawan Budiarto, and Ridwan Budi Prasetyo. "Optimizing Energy Output for Oscillating Water Column (OWC) Wave Energy Converter System at Pantai Baron, Gunung Kidul, DI Yogyakarta." Applied Engineering and Technology 3, no. 2 (2024): 125–32. https://doi.org/10.31763/aet.v3i2.1773.
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The prototypes of the Oscillating Water Column (OWC) system constructed by BPPT at Pantai Baron, Gunung Kidul, in 2005 and 2006 were not sustainable. Based on its condition and location, the root cause of the problem was defined. Maximizing the total efficiency and capacity factor (Cf) of the OWC system was the main factor for optimizing energy output. Collecting factors that constructed the total efficiency and capacity factor of the OWC system was conducted. Selecting the appropriate turbine, generator, and chamber system led to an increase in the total efficiency of the OWC system. Reducing the effect of wave diffraction, finding optimum wave data for forecasting, finding optimum water depth area to avoid wave breaking area, reducing corrosion chance by selecting the optimum height of the OWC system, and using a control system to minimize stalling on turbine were factors that constructed capacity factor
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Medina Rodríguez, Ayrton Alfonso, Gregorio Posada Vanegas, Rodolfo Silva Casarín, et al. "Experimental Investigation of the Hydrodynamic Performance of Land-Fixed Nearshore and Onshore Oscillating Water Column Systems with a Thick Front Wall." Energies 15, no. 7 (2022): 2364. http://dx.doi.org/10.3390/en15072364.
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Most experimental research on land-fixed Oscillating Water Column (OWC) systems assume that the OWC-water wave interaction happens with waves that propagate normally towards the device. However, the angle of incidence of the waves can determine the performance of the OWC, in particular the wave period at which the device resonates. In this study, an experimental investigation to examine the interaction of regular, oblique, water waves with a land-fixed, thick-front wall OWC device in terms of its hydrodynamic performance is reported. A 1:20 Froude scale was used to replicate a single chamber of the Mutriku Wave Energy Plant (MWEP), and a series of tests were carried out in a spectral wave basin. The goal of this study is to look at how incident wave direction and device location affect the hydrodynamic performance of land-fixed OWC systems in regular wave conditions with varying wave heights. The hydraulic performance includes the assessment of the wave amplification factor, hydrodynamic efficiency, the non-dimensional air pressure inside the chamber and non-dimensional water pressures on the chamber walls. The findings show that, for the nearshore OWC device, the period at which resonance occurs decreases when the incident wave angle increases. For the corresponding wave angles, similar results were found for the onshore and nearshore OWC devices, with a slight frequency shift in the bandwidth of the hydrodynamic efficiency. Furthermore, it was found that when wave height increases, the hydrodynamic efficiency improves for both short and long wave periods, with the exception of the resonance period, where the trend is reversed. Finally, regardless of the location, an OWC device with a thick front wall performs well when interacting with intermediate and long-period waves.
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Benreguig, Pierre, Vikram Pakrashi, and Jimmy Murphy. "Assessment of Primary Energy Conversion of a Closed-Circuit OWC Wave Energy Converter." Energies 12, no. 10 (2019): 1962. http://dx.doi.org/10.3390/en12101962.
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Tupperwave is a wave energy device based on the Oscillating-Water-Column (OWC) concept. Unlike a conventional OWC, which creates a bidirectional air flow across the self-rectifying turbine, the Tupperwave device uses rectifying valves to create a smooth unidirectional air flow, which is harnessed by a unidirectional turbine. This paper deals with the development and validation of time-domain numerical models from wave to pneumatic power for the Tupperwave device and the conventional OWC device using the same floating spar buoy structure. The numerical models are built using coupled hydrodynamic and thermodynamic equations. The isentropic assumption is used to describe the thermodynamic processes. A tank testing campaign of the two devices at 1/24th scale is described, and the results are used to validate the numerical models. The capacity of the innovative Tupperwave OWC concept to convert wave energy into useful pneumatic energy to the turbine is assessed and compared to the corresponding conventional OWC.
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El Barakaz, Abdelhamid, Abdellatif El Marjani, and Hamid Mounir. "Effect of wall inclination on the dynamic behaviour of an oscillating water column system." MATEC Web of Conferences 307 (2020): 01021. http://dx.doi.org/10.1051/matecconf/202030701021.
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The Oscillating Water Column device (OWC) is one of the most used Wave Energy Converters (WECs) for wave energy harvesting. It consists essentially of two parts: the pneumatic chamber made of concrete and the bidirectional turbine linked to a generator group for energy production. In this study we are interested in the water motion oscillation inside the chamber resulting from the water level perturbation. This process is characterized by its own natural frequency and global damping. The vertical OWC chamber model is limited by the number of parameters defining the natural frequency and the global damping. The objective of this paper is to improve the performances obtained for the vertical OWC by considering an OWC with inclined sidewalls. For maximum efficiency, the device must operate in the resonance domain where the damping is low and the frequency of incoming waves matches with the natural frequency of the OWC. This will theoretically amplify the pneumatic energy to be converted to a mechanical one in the turbine.
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Kanyan, Lawrence. "Post-oil-migration structural deformation: a possible mechanism for the genesis of the tilted oil–water contact of the Mumbai High Oilfield, India." Petroleum Geoscience 26, no. 3 (2019): 499–510. http://dx.doi.org/10.1144/petgeo2019-016.
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The presence of a complicated, variable-depth oil–water contact (OWC) in the Early Miocene L-III carbonate reservoir of the Mumbai High Oilfield has been well established. The OWC dips towards the SW along a curved profile, but the gas–oil contact (GOC) is flat. Very little is known about the possible mechanisms that could have produced this complex fluid contact. In the absence of a horizontal pressure gradient, gravity should produce a flat OWC. In many fields around the world, where non-flat fluid contacts are observed, the contacts could be described as segmented, tilted or curved OWCs. Commonly believed mechanisms which produce such types of contacts are: fault compartmentalization, hydrodynamic flow, ongoing charge; and reservoir property variation. All these mechanisms fail to explain the tilted OWC of the Mumbai High. This paper proposes that another mechanism – structural adjustments after the migration of hydrocarbons into the palaeotrap – might have resulted in tilting or curving of the originally flat OWC of the Mumbai High. Such a phenomenon is likely to be observed in oil-wet low-permeability carbonate reservoirs. Imbibition-related hysteresis combined with diagenesis-induced property degradation in the water leg are the possible mechanisms that can prevent the OWC from equilibrating even after cessation of structural evolution.
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Deng, Zhengzhi, Zhenhua Huang, and Adrian W. K. Law. "Wave power extraction from a bottom-mounted oscillating water column converter with a V-shaped channel." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 470, no. 2167 (2014): 20140074. http://dx.doi.org/10.1098/rspa.2014.0074.
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An analytical theory is developed for an oscillating water column (OWC) with a V-shaped channel to improve the pneumatic efficiency of wave energy extraction. An eigenfunction expansion method is used in a cylindrical coordinate system to investigate wave interaction with the OWC converter system. Auxiliary functions are introduced to capture the singular behaviours in the velocity field near the salient corners and cusped edges. Effects of the OWC dimensions, the opening angle and length of the V-shaped channel, as well as the incident wave direction, on the pneumatic efficiency of wave energy extraction are examined. Compared with a system without the V-shaped channel, our results show that the V-shaped channel can significantly increase the conversion efficiency and widen the range of wave frequency over which the OWC system can operate at a high efficiency. For typical coastal water depths, the OWC converter system can perform efficiently when the diameter of the OWC chamber is in the range of 1 5 – 1 2 times the water depth, the opening angle of the V-shaped channel is in the range of [ π /2, 3 π /4] and the length of the V-shaped channel is in the range of 1–1.5 times the water depth.
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Wang, Zhaocheng, and Jiaxuan Chen. "Networked multiple-input-multiple-output for optical wireless communication systems." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 378, no. 2169 (2020): 20190189. http://dx.doi.org/10.1098/rsta.2019.0189.
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With the escalation of heterogeneous data traffic, the research on optical wireless communication (OWC) has attracted much attention, owing to its advantages such as wide spectrum, low power consumption and high security. Ubiquitous optical devices, e.g. light-emitting diodes (LEDs) and cameras, are employed to support optical wireless links. Since the distribution of these optical devices is usually dense, multiple-input-multiple-output (MIMO) can be naturally adopted to attain spatial diversity gain or spatial multiplexing gain. As the scale of OWC networks enlarges, optical MIMO can also collaborate with network-level operations, like user/AP grouping, to enhance the network throughput. Since OWC is preferred for short-range communications and is sensitive to the directions/rotations of transceivers, optical MIMO links vary frequently and sharply in outdoor scenarios when considering the mobility of optical devices, raising new challenges to network design. In this work, we present an overview of optical MIMO techniques, as well as the cooperation of MIMO and user/AP grouping in OWC networks. In consideration of the challenges for outdoor OWC, key technologies are then proposed to facilitate the adoption of optical MIMO in outdoor scenarios, especially in vehicular ad hoc networks. Lastly, future applications of MIMO in OWC networks are discussed. This article is part of the theme issue ‘Optical wireless communication’.
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Fang, Chengwei, Shuo Li, Yinong Wang, and Ke Wang. "Survey on Optical Wireless Communication with Intelligent Reflecting Surfaces." Photonics 11, no. 9 (2024): 830. http://dx.doi.org/10.3390/photonics11090830.
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Optical Wireless Communication (OWC) technology has gained significant attention in recent years due to its potential for providing high-data-rate wireless connections through the large license-free bandwidth available. A key challenge in OWC systems, similar to high-frequency Radiofrequency (RF) systems, is the presence of dead zones caused by obstacles like buildings, trees, and moving individuals, which can degrade signal quality or disrupt data transmission. Traditionally, relays have been used to mitigate these issues. Intelligent Reflecting Surfaces (IRSs) have recently emerged as a promising solution, enhancing system performance and flexibility by providing reconfigurable communication channels. This paper presents an overview of the application of IRSs in OWC systems. Specifically, we categorize IRSs into two main types: mirror array-based IRSs and metasurface-based IRSs. Furthermore, we delve into modeling approaches of mirror array-based IRSs in OWC and analyze recent advances in IRS control, which are classified into system power or gain optimization-oriented, system link reliability optimization-oriented, system data rate optimization-oriented, system security optimization-oriented, and system energy optimization-oriented approaches. Moreover, we present the principles of metasurface-based IRSs from a physical mechanism perspective, highlighting their application in OWC systems through the distinct roles of light signal refraction and reflection. Finally, we discuss the key challenges and potential future directions for integrating IRS with OWC systems, providing insights for further research in this promising field.
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J.E.SIVA, Mr, Y. SAI KUMAR, G. DEEPTHIKA, P. MEGHANA, R. JAYANTH KUMAR, and M. TEJASWINI. "Development of Optical Wireless Communication for Indoor Environment." INTERANTIONAL JOURNAL OF SCIENTIFIC RESEARCH IN ENGINEERING AND MANAGEMENT 09, no. 04 (2025): 1–9. https://doi.org/10.55041/ijsrem44251.
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The increasing demand for wireless communication has led to the development of various wireless technologies. One such technology is optical wireless communication (OWC), which uses light to transmit data. This project aims to develop an OWC system for indoor environments, which can provide high-speed, reliable, and secure communication. The system will use visible light communication (VLC) technology, which uses visible light to transmit data. The project will involve the design and development of an OWC system, which will include a transmitter, receiver, and communication protocol. This technology envisions a future where data for laptops, smart phones, and tablets will be transmitted in an economic and eco-friendly medium of light in room. Keywords- Optical Wireless Communication(OWC), Visible Light Communication(VLC), Indoor Communication Systems, Wireless Data Transmission.
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Lee, Hsien Hua, and Cheng-Han Chen. "Parametric Study for an Oscillating Water Column Wave Energy Conversion System Installed on a Breakwater." Energies 13, no. 8 (2020): 1926. http://dx.doi.org/10.3390/en13081926.
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This study focuses on the analysis of the parameters of an oscillating water column (OWC) wave energy conversion system and wave conditions. Interactions between the dimensions of the OWC chambers and wave conditions are all taken into account to design an alternative OWC converter, called caisson-based OWC type wave energy converting system. A numerical method using an unsteady Navier-Stokes equations theorem in conservation form is used to analyze the proposed analytical model. The objective of this study is to try to apply an OWC wave energy converter to a caisson breakwater, which has been constructed in a harbor. The structure proposed in this study is a series of sets of independent systems, in which each set of converters is composed of three chambers to capture the wave energy, while better ensuring the safety of the caisson breakwater. Responses to be analyzed related to the conversion efficiency of the caisson-based OWC wave energy converting system include the airflow velocity from the air-chamber, the pneumatic power and the conversion efficiency in terms of a ratio between the pneumatic power and the energy of the incident waves. Parameters examined in this study include the dimensions of the OWC chamber features such as the orifice of the air-chamber allowing airflow in/output, the chamber length along the direction of incident waves, the size of the opening gate for incident waves and the submersion depth of the air-chamber. As found from the results, a best conversion efficiency from incident waves of 32% can be obtained for the extreme case where the orifice is very small, but for most other cases in the study, the best efficiency is about 15%.
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Rohaizad Hafidz Rozali, Muhammad Adli Mustapa, Mohd Amin Hakim Ramli, Muhammad Nasuha Mansor, Iwan Zamil Mustaffa Kamal, and Engku Ahmad Azulhisham Engku Mohamed. "Design an Optimum Air Duct for Oscillating Water Column Wave Energy Device." Journal of Advanced Research in Applied Sciences and Engineering Technology 34, no. 1 (2023): 164–76. http://dx.doi.org/10.37934/araset.34.1.164176.
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Oscillating Water Column (OWC) is a technology that harvests wave energy to generate electricity. It works by harnessing the wave-induced pressure oscillation in the opening mouth of OWC. The oscillation of the pressurised air is extracted using a turbine placed at the top of the OWC structure. Although OWC has been studied for many years, designing an optimum air duct for such devices is still an open research area. The air duct plays a crucial role in the energy conversion process, as it is responsible for directing the airflow towards the turbine, and its design can greatly affect the performance and efficiency of the system. The article aims to study how the air duct design impacts the power output form. Moreover, the result will be compared with the conventional air duct design. The OWC performance is analysed using Computational Fluid Dynamic (CFD) software to identify which shape of the air duct has high efficiency. Autodesk Inventor is used to design the OWC devices modified from the basis design. Then these designs are imported into CFD software to simulate and obtain the energy extraction result. The CFD software is chosen to simulate the hydrodynamics problem. In this study, the oval design shows significant improvement in the energy extraction performance compared to the basis design. The oval design managed to produce 9.81, 10.02, and 11.66 J/kg of mechanical energy compared to 9.81, 9.82, and 10.04J/kg as prompted by the basis air duct design at the wave height of 0.2505, 0.75, and 2.25m, respectively. The result shows that the non-edge produces higher air pressure than the sharp edge of the air duct shape. Thus, the oval air duct design is more efficient, and it may increase the performance of the OWC wave energy converter device at a low wave height of 0.75 m.
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Gomes, Mateus das Neves, Heloiza Salvador, Felipe Magno, et al. "Constructal Design Applied to Geometric Shapes Analysis of Wave Energy Converters." Defect and Diffusion Forum 407 (March 2021): 147–60. http://dx.doi.org/10.4028/www.scientific.net/ddf.407.147.
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This paper deals with numerical simulation and the geometrical analysis of an ocean Wave Energy Converter (WEC), which has as the operating principle the Oscillating Water Column (OWC). The goal was to evaluate the geometric shape influence of the OWC chamber in the hydropneumatic power available. Therefore, four geometric shapes were analyzed: i) Rectangle (RT), ii) Trapezium (TP), iii) Inverted Trapezium (TI) and iv) Double Trapezium (DT). For this, the OWC device was subject to a JONSWAP wave spectrum with peak period (TS) equal to 7.5 s and peak wave height (HS) equal to 1.5 m. To do so, Constructal Design was employed varying the Degree Of Freedom (DOF) H1/L (ratio between the height and length of the OWC chamber entrance). The problem constraints were the entrance area and the total area of the OWC chamber that were kept constant. For the numerical solution a Computational Fluid Dynamics (CFD) code, based on the Finite Volume Method (FVM),de0 was used. The multiphase Volume of Fluid (VOF) model was applied to tackle with the water-air interaction. The results indicated that when the Rectangle (RT) geometrical shape was employed an improvement of nearly 99% was achieved.
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Aries Taufik Kurniawan, Arief Budiman, Rachmawan Budiarto, and Ridwan Budi Prasetyo. "Wave Energy Potential Using OWC (Oscillating Water Column) System at Pantai Baron, Gunung Kidul, DI Yogyakarta, Indonesia." Journal of Advanced Research in Fluid Mechanics and Thermal Sciences 92, no. 2 (2022): 191–201. http://dx.doi.org/10.37934/arfmts.92.2.191201.
Full textAbstract:
The southern coast of Yogyakarta province in Indonesia has large potential for wave energy, where the most ideal location is Pantai Baron. This research was conducted to study the potential wave energy using OWC (Oscillating Water Column) at Pantai Baron. Wave height and wave periods are needed to find the potential wave energy that can be generated. Wind, fetch and bathymetry data will be used to determine wave height in deep sea. Refraction and shoaling calculation will be used to calculate wave height in shallow depth area. Wave height after refraction-shoaling combine with tidal data will be used to determine optimum position for OWC system. Wave height, wave incoming direction, total efficiency for OWC system and capacity factor will be used to calculate potential wave energy that can be produced. Average wave height on deep sea is 1.08 m, wave period is 9.73 sec and incoming wave dominant is from east. Optimum depth of system OWC is -5.0 m below MSL. Average wave height after refraction and shoaling effect is 1.1 – 1.2 m. Potential wave energy that can be generated is 3.9 – 5.6 MWh per year per 1 OWC system with chamber width is 2.4 m.
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Didier, Eric, and Paulo R. F. Teixeira. "Performance of an L-Shaped Duct OWC-WEC Integrated into Vertical and Sloped Breakwaters by Using a Free-Surface RANS-Based Numerical Model." Fluids 10, no. 5 (2025): 114. https://doi.org/10.3390/fluids10050114.
Full textAbstract:
Waves generated by the wind in oceans and seas have a significant available quantity of clean and renewable energy. However, harvesting their energy is still a challenge. The integration of an oscillating water column (OWC) wave energy converter into a breakwater leads to more viability, since it allows working as both harbor and coastal protection and harvesting wave energy. The main objective of this study is to investigate different configurations of L-shaped duct OWC devices inserted into vertical and sloped (2:3) impermeable breakwaters for different lengths of the lip by using a numerical model based on the Reynolds-Averaged Navier-Stokes equations. The ANSYS FLUENT® software (2016) is used in 2D numerical simulations by adopting the volume of fluid method to consider the two-phase free surface flow (water and air). It was observed that both the length of the lip and the length of the L-shaped duct OWC significantly influence the resonance and the efficiency of the OWC device. In addition, the performance of the OWC device varies significantly with its geometric configuration, which needs to be adapted for the local sea state.
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Narasimhareddy, A. S., Gowda K. R. Ventatesh, and P. Madhumathy. "OWC-Based for Communication Autonomous Vehicles." Journal of Sensor Research and Technologies 7, no. 1 (2025): 11–22. https://doi.org/10.5281/zenodo.14791974.
Full textAbstract:
<em>Optical Wireless Communication (OWC) has emerged as a promising technology for enabling high-speed, secure, and reliable communication for autonomous vehicles. This paper investigates the application of OWC, specifically Visible Light Communication (VLC) and Free Space Optical (FSO) systems, in vehicular environments. Key contributions include the development of a communication model leveraging OWC to support vehicle-to-vehicle (V2V) and vehicle-to- infrastructure (V2I) communications. The study also evaluates the system's performance under various environmental conditions and proposes methods to mitigate challenges such as interference and atmospheric attenuation.</em>
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Ali, Zakir, Chen Sun, Qasim Jan, Muhammad Furqan, and Xiqi Gao. "Precoder Design for Network Massive MIMO Optical Wireless Communications." Sensors 24, no. 16 (2024): 5188. http://dx.doi.org/10.3390/s24165188.
Full textAbstract:
Precoding is a technique employed to enhance transmission rates in various communication systems, including massive multiple-input multiple-output (MIMO) and optical wireless communication (OWC). In this study, we focus on network massive MIMO OWC (NM-MIMO-OWC) systems and investigate the precoder design to enhance the sum rate and improve the system performance. We present the network’s massive MIMO OWC framework. By utilizing this framework, we are able to calculate the achievable sum rate. Subsequently, we consider the precoding design for maximizing the sum rate while adhering to the total power constraint. To solve this optimization problem, we provide a necessary condition of the optimal solution based on the Karush–Kuhn–Tucker (KKT) conditions, and propose a low-complexity algorithm to further enhance the efficiency of the proposed precoding technique. The numerical results demonstrate that the proposed precoder design significantly improves the transmission rate and effectively maximizes the sum rate.
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Al-Rubaye, Wisam I., Dhiaa S. Ghanem, Hussein Mohammed Kh, Hayder Abdulzahra, Ali M. Saleem, and Abbas R. Abbas. "Estimation of Oil-Water Contact Level Using Different Approaches: A Case Study for an Iraqi Carbonate Reservoir." Journal of Petroleum Research and Studies 10, no. 2 (2020): 95–113. http://dx.doi.org/10.52716/jprs.v10i2.354.
Full textAbstract:
In petroleum industry, an accurate description and estimation of the Oil-Water Contact(OWC) is very important in quantifying the resources (i.e. original oil in place (OIIP)), andoptimizing production techniques, rates and overall management of the reservoir. Thus,OWC accurate estimation is crucial step for optimum reservoir characterization andexploration. This paper presents a comparison of three different methods (i.e. open holewell logging, MDT test and capillary pressure drainage data) to determine the oil watercontact of a carbonate reservoir (Main Mishrif) in an Iraqi oil field "BG”. A total of threewells from "BG" oil field were evaluated by using interactive petrophysics software "IPv3.6". The results show that using the well logging interpretations leads to predict OWCdepth of -3881 mssl. However, it shows variance in the estimated depth (WELL X; -3939,WELL Y; -3844, WELL Z; -3860) mssl, which is considered as an acceptable variationrange due to the fact that OWC height level in reality is not constant and its elevation isusually changed laterally due to the complicated heterogeneity nature of the reservoirs.Furthermore, the results indicate that the MDT test can predict a depth of OWC at -3889mssl, while the capillary drainage data results in a OWC depth of -3879 mssl. The properMDT data and SCAL data are necessary to reduce the uncertainty in the estimationprocess. Accordingly, the best approach for estimating OWC is the combination of MDTand capillary pressure due to the field data obtained are more reliable than open hole welllogs with many measurement uncertainties due to the fact of frequent borehole conditions.
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George, Arun, Il-Hyoung Cho, and Moo-Hyun Kim. "Optimal Design of a U-Shaped Oscillating Water Column Device Using an Artificial Neural Network Model." Processes 9, no. 8 (2021): 1338. http://dx.doi.org/10.3390/pr9081338.
Full textAbstract:
A U-shaped oscillating water column (U-OWC) device has been investigated to enhance power extraction by placing the bottom-mounted vertical barrier in front of a conventional OWC. Then, the optimal design of a U-OWC device has been attempted by using an artificial neural network (ANN) model. First, the analytical model is developed by a matched eigenfunction expansion method (MEEM) based on linear potential theory. Using the developed analytical model, the input and output features for training an ANN model are identified, and then the database containing input and output features is established by a Latin hypercube sampling (LHS) method. With 200 samples, an ANN model is trained with the training data (70%) and validated with the remaining test data (30%). The predictions on output features are made for 4000 random combinations of input features for given significant wave heights and energy periods in irregular waves. From these predictions, the optimal geometric values of a U-OWC are determined by considering both the conversion efficiency and wave force on the barrier. It is found that a well-trained ANN model shows good prediction accuracy and provides the optimal geometric values of a U-OWC suitable for wave conditions at the installation site.