Browsing by Keyword "Wave Energy Conversion"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Mooring System Design Approach: A Case Study for MARMOK-A Floating OWC Wave Energy Converter(American Society of Mechanical Engineers (ASME), 2018) Touzon, Imanol; de Miguel, Borja; Nava, Vincenzo; Petuya, Victor; Mendikoa, Iñigo; Boscolo, Francesco; Tecnalia Research & Innovation; RENOVABLES OFFSHOREThis paper presents a methodology and a flowchart of steps to take for a, consistent and rapidly convergent design of catenary mooring systems. It is subsequently applied for a floating Oscillating Water Column WEC MARMOK-A developed by Oceantec Energías Marinas, in order to fulfill the technical requirements of such dynamic systems. The approach, based on the catenary equations, considers the water depth as a design scale factor for the mooring system, leading to an equivalent static mooring performance. In general, a mooring system configuration is described by the number and distribution of lines; thus, as a preprocess in the herein described procedure, a database is built for different line lengths. The main advantage of the procedure is that once that, after characterizing a mooring system configuration at a specific water depth with a specific line mass and axial stiffness, the database built can be used for any other water depth with any line mass and axial stiffness, accelerating the design optimization process. Mooring static properties are derived for a given material elastic modulus, lines’ mass and water depth. The mean offset and horizontal stiffness are afterwards derived with lines pretension and steady environmental forces (mean wave drift, current and wind) as well as maximum offset and characteristic line tensions. Finally, the process is applied for different lines pretensions to achieve an objective horizontal stiffness of the structure. The introduced procedure is presented through its application to the MARMOK-A device at a 90m depth site moored by means of a Karratu named mooring configuration. Results are presented in terms of total lines mass, device maximum expected excursion and required footprint for different horizontal stiffness and lines mass in order to give an insight of the impact on total plant cost indicators.Item A Power Take-Off Behaviour at High Pressure Operation Point, Using Four Double-acting Hydraulic Cylinders Modelled by a Port-based Approach(2015-09) Antolín-Urbaneja, Juan Carlos; Cortes, A.; Marcos, Marga; Lasa, Joseba; Cabanes, Itziar; Tecnalia Research & InnovationThis paper deals with the behaviour at high pressure operation points of a hydraulic Power Take-Off (PTO) using a highly detailed model based on four double-acting hydraulic cylinders modelled by a port-based approach. The developed model takes advantage of the availability of basic hydraulic components which can be parameterized based on real ones, including most of the hydraulic losses. With the aim of optimizing the extraction of wave energy, this PTO is able to modify its restraining torque through the independent activation of the hydraulic cylinders located in the primary transmission and modifying some geometrical parameters related to their fixation points respecting to the axis torque. The ultimate objective of this PTO is to provide a wide range of torques that can be modulated by modifying the operating high pressure of the HP accumulator, the combination of the available areas of the double-acting hydraulic cylinder and the location of their fixation points with respect to the applied movement. This factor can help to improve the control of WEC based on activated bodies with the aim to optimize the extraction of wave energy. In this paper an extended simulation results at different operation points and input movements are presented.