Validation of numerical models of the offshore wind turbine from the alpha ventus wind farm against full-scale measurements within OC5 Phase III

The main objective of the Offshore Code Comparison Collaboration Continuation, with Correlation (OC5) project is validation of aero-hydro-servo-elastic simulation tools for offshore wind turbines (OWTs) through comparison of simulated results to the response data of physical systems. Phase III of the OC5 project validates OWT models against the measurements recorded on a Senvion 5M wind turbine supported by the OWEC Quattropod from the alpha ventus offshore wind farm. The following operating conditions of the wind turbine were chosen for the validation: (1) idling below the cut-in wind speed, (2) rotor-nacelle assembly (RNA) rotation maneuver below the cut-in wind speed, (3) power production below and above the rated wind speed, and (4) shutdown. A number of validation load cases were defined based on these operating conditions. The following measurements were used for validation: (1) strains and accelerations recorded on the support structure and (2) pitch, yaw, and azimuth angles, generator speed, and electrical power recorded from the RNA. Strains were not directly available from the majority of the OWT simulation tools; therefore, strains were calculated based on out-of-plane bending moments, axial forces, and cross-sectional properties of the structural members. The simulation results and measurements were compared in terms of time series, discrete Fourier transforms, power spectral densities, and probability density functions of strains and accelerometers. A good match was achieved between the measurements and models setup by OC5 Phase III participants.OWEC Tower is acknowledged for releasing the jacket substructure, transition piece, and foundation design data for Phase III. Senvion is acknowledged for sharing the definition of the Senvion 5M wind turbine and its tower. The RAVE consortium is acknowledged for releasing the measurement data from the alpha ventus wind farm. This work was authored (in part) by the National Renewable Energy Laboratory, operated by Alliance for Sustainable Energy, LLC, for the U.S. Department of Energy (DOE) under Contract No. DE-AC36-08GO28308. Funding provided by the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Wind Energy Technologies Office. The views expressed in the article do not necessarily represent the views of the DOE or the U.S. Government. The submitted manuscript has been created by UChicago Argonne, LLC, Operator of Argonne National Laboratory (“Argonne”). Argonne, a U.S. Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan. http://energy.gov/downloads/doe-public-accessplanPeer ReviewedWojciech Popko / Fraunhofer IWES, Fraunhofer Institute for Wind Energy Systems / , Division Wind Turbine and System Technology, Am Luneort 100, Bremerhaven 27572 / , Germany / Amy Robertson / National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 / Jason Jonkman / National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 / Fabian Wendt / National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 / Philipp Thomas / Fraunhofer IWES, Fraunhofer Institute for Wind Energy Systems / , Division Wind Turbine and System Technology, Am Luneort 100, Bremerhaven 27572 / , Germany / Kolja Müller / University of Stuttgart / , Allmandring 5b, Stuttgart Wind Energy, Stuttgart 70569 / , Germany / Matthias Kretschmer / University of Stuttgart / , Allmandring 5b, Stuttgart Wind Energy, Stuttgart 70569 / , Germany / Torbjørn Ruud Hagen / OWEC Tower AS, Sommerrogata 17, Oslo 0255 / , Norway / Christos Galinos / Technical University of Denmark / , Department of Wind Energy, Frederiksborgvej 399, Roskilde 4000 / , Denmark / Jean-Baptiste Le Dreff / Electricitéde France, Recherche et Développement, 13 Boulevard Gaspard Monge, Palaiseau 91120 / , France / Philippe Gilbert / IFP Energies Nouvelles, 1 et 4 avenue de Bois-Préau, 92852 Rueil-Malmaison Cedex / , France / Bertrand Auriac / Principia La Ciotat, 215 Voie Ariane, La Ciotat 13600 / , France / Sho Oh / Nippon Kaiji Kyokai (ClassNK), 4-7 Kioicho, Chiyoda-Ku, Tokyo 102-8567 / , Japan / Jacob Qvist / 4Subsea, Hagaløkkveien 26, 1383 Asker, Hvalstad / , Norway / Stian Høegh Sørum / Norwegian University of Science and Technology / , Department of Marine Technology, Trondheim 7491 / , Norway / Loup Suja-Thauvin / Simis AS, Leonardveien 3, Malm 7790 / , Norway / Hyunkyoung Shin / University of Ulsan / , School of Naval Architecture and Ocean Engineering, Ulsan / , South Korea / Climent Molins / Polytechnic University of Catalonia / , Campus Nord, Carrer de Jordi Girona, 1, 3, Barcelona 08034 / , Spain / Pau Trubat / Polytechnic University of Catalonia / , Campus Nord, Carrer de Jordi Girona, 1, 3, Barcelona 08034 / , Spain / Paul Bonnet / Siemens Industry Software, Luis, Carrer Lluís Muntadas, No. 5, Cornellà de Llobregat, Barcelona 08940 / , Spain / Roger Bergua / Envision Energy Limited, 8/F, Building B, SOHO Zhongshan Plaza, 1065 West Zhongshan Road, Shanghai 200051 / , China / Kai Wang / Envision Energy Limited, 8/F, Building B, SOHO Zhongshan Plaza, 1065 West Zhongshan Road, Shanghai 200051 / , China / Pengcheng Fu / China General Certification Center, Room 1108, Yiheng Building No. 28, North 3rd Ring Road East, Chaoyang District, Beijing 100013 / , China / Jifeng Cai / China General Certification Center, Room 1108, Yiheng Building No. 28, North 3rd Ring Road East, Chaoyang District, Beijing 100013 / , China / Zhisong Cai / China General Certification Center, Room 1108, Yiheng Building No. 28, North 3rd Ring Road East, Chaoyang District, Beijing 100013 / , China / Armando Alexandre / DNV GL, One Linear Park, Avon Street, Temple Quay, Bristol BS2 0PS / , UK / Robert Harries / DNV GL, Edificio Trovador, Plaza de Antonio Beltrán Martínez, Zaragoza 50002 / , SpainPostprint (published version

Offshore Code Comparison Collaboration Continuation (OC4), Phase I – Results of Coupled Simulations of an Offshore Wind Turbine with Jacket Support Structure

Heike von Waaden (REpower Systems SE) To be presented at the 22 nd International Society of Offshore and Polar Engineers Conference Rhodes, Greec

OC5 Project Phase II: Validation of Global Loads of the DeepCwind Floating Semisubmersible Wind Turbine

This paper summarizes the findings from Phase II of the Offshore Code Comparison, Collaboration, Continued, with Correlation project. The project is run under the International Energy Agency Wind Research Task 30, and is focused on validating the tools used for modeling offshore wind systems through the comparison of simulated responses of select system designs to physical test data. Validation activities such as these lead to improvement of offshore wind modeling tools, which will enable the development of more innovative and cost-effective offshore wind designs. For Phase II of the project, numerical models of the DeepCwind floating semisubmersible wind system were validated using measurement data from a 1/50th-scale validation campaign performed at the Maritime Research Institute Netherlands offshore wave basin. Validation of the models was performed by comparing the calculated ultimate and fatigue loads for eight different wave-only and combined wind/wave test cases against the measured data, after calibration was performed using free-decay, wind-only, and wave-only tests. The results show a decent estimation of both the ultimate and fatigue loads for the simulated results, but with a fairly consistent underestimation in the tower and upwind mooring line loads that can be attributed to an underestimation of waveexcitation forces outside the linear wave-excitation region, and the presence of broadband frequency excitation in the experimental measurements from wind. Participant results showed varied agreement with the experimental measurements based on the modeling approach used. Modeling attributes that enabled better agreement included: the use of a dynamic mooring model; wave stretching, or some other hydrodynamic modeling approach that excites frequencies outside the linear wave region; nonlinear wave kinematics models; and unsteady aerodynamics models. Also, it was observed that a Morison-only hydrodynamic modeling approach could create excessive pitch excitation and resulting tower loads in some frequency bands.This work was supported by the U.S. Department of Energy under Contract No. DEAC36- 08GO28308 with the National Renewable Energy Laboratory. Some of the funding for the work was provided by the DOE Office of Energy Efficiency and Renewable Energy, Wind and Water Power Technologies Office

Verification of a Numerical Model of the Offshore Wind Turbine From the Alpha Ventus Wind Farm Within OC5 Phase III

The main objective of the Offshore Code Comparison Collaboration Continuation, with Correlation (OC5) project, is validation of aero-hydro-servo-elastic simulation tools for offshore wind turbines (OWTs) through comparison of simulated results to the response data of physical systems. Phase III of the OC5 project analyzes the Senvion 5M wind turbine supported by the OWEC Quattropod from the alpha ventus offshore wind farm. This paper shows results of the verification of the OWT models (code-to-code comparison). A subsequent publication will focus on their validation (comparison of simulated results to measured physical system response data). Based on the available data, the participants of Phase III set up numerical models of the OWT in their simulation tools. It was necessary to verify and to tune these models. The verification and tuning were performed against an OWT model available at the University of Stuttgart - Stuttgart Wind Energy (SWE) and documentation provided by Senvion and OWEC Tower. A very good match was achieved between the results from the reference SWE model and models set up by OC5 Phase III participants

Aero-Elastic Simulation Time Series of IWT7.5 Reference Turbine

This set of time series comprises simulation time series of the IWT7.5 reference wind turbine (Revision 2.5) with an IPC controller. The turbine model is available online (first reference), a detailed description of the controller is part of the second reference. The signals of the files are WindSpeed, ElectricalPower, and pitch angles and loads of three blades.The folder names follow the DLC convention of IEC61400. The file names follow the pattern d.d_sxyyzz were d.d. is the DLC, s refers to a stiff foundation, x to the shear factor, yy to the seed and zz to the mean wind speed. The yaw error is included in each file, there are no separate file for yaw misalginments

Educational Use of 3D Printers

W niniejszym artykule poruszona została tematyka zastosowania drukarek 3D w procesie edukacji. Na wstępie zaprezentowana została krótka historia druku 3D. Kolejna część poświęcona została omówieniu wybranych technik stosowanych w tych urządzeniach. Zaprezentowane zostały jedynie te, które autorzy uznali za najciekawsze z punktu widzenia wykorzystania ich w edukacji. Ostatnia część poświęcona została zaprezentowaniu obszarów edukacyjnych, w których z powodzeniem może być zastosowana drukarka 3D.In this article we discussed was the subject of the use of 3D printers in the educational process. At the outset, it was presented a brief history of 3D printing. Another part is devoted to the discussion of selected techniques used in these devices. Presented are only those that the authors considered it the most interesting from the point of view of their use in education. The last part is devoted to the presentation of educational areas in which it can successfully be applied to a 3D printer

Exclusively endoscopic approach for juvenile angiofibroma in an adult – a case report

Aim: To demonstrate clinical, radiological, and diagnostic pitfalls of juvenile angiofibroma (JA) in an adult.Study design: Retrospective analysis of a case report.Results: Juvenile angiofibroma in adults is a rare entity with only two cases reported in the literature, confirming thelow prevalence of the disease. We present a case of juvenile angiofibroma in an adult that preoperatively wassuspected to be a malignant disease. Effective treatment included surgical excision via an exclusively endoscopicapproach.Conclusions: Symptoms of JA in an adult may mimic a malignant process. However, in the case of unilateral epistaxis,rhinorrhea and nasal obstruction in an adult JA should be considered in the differential diagnosis

Integrated stress response activation by sleep fragmentation during late gestation in mice leads to emergence of adverse metabolic phenotype in offspring

International audienc