Download or read book SeaLOWT Impact of Sea Ice Loads on Global Dynamics of Offshore Wind Turbines written by Wojciech Popko and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Impact of Sea Ice Loads on Global Dynamics of Offshore Wind Turbines written by Wojciech Popko and published by Fraunhofer Verlag. This book was released on 2020-12-10 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Support structures for offshore wind turbines (OWTs) are designed and certified site-specific based on the calculated load effects. These load effects originate from static, cyclic, stochastic, and transient loads from the met-ocean environment and rotating components of the wind turbine. The met-ocean environment of the Baltic Sea accounts for variable wind and marine conditions. Sea ice is part of marine conditions - which among others - should be included in the design process of OWT support structures. The load analysis and design of OWTs, including its components, rely on the time-domain based, coupled aero-hydro-servo-elastic simulation tools. Only this approach can provide an accurate prediction of the OWT dynamic response. Dynamic interaction between an OWT and external loads - including ice loads - cannot be disregarded as it may result in considerable loss of accuracy. A proper understanding of sea ice impact on the global dynamics of OWTs - involving the fully-integrated simulation approach - is necessary within the offshore wind research community, industry, and certification authorities.

Download or read book Ice Load Project Final Technical Report written by and published by . This book was released on 2014 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: As interest and investment in offshore wind projects increase worldwide, some turbines will be installed in locations where ice of significant thickness forms on the water surface. This ice moves under the driving forces of wind, current, and thermal effects and may result in substantial forces on bottom-fixed support structures. The North and Baltic Seas in Europe have begun to see significant wind energy development and the Great Lakes of the United States and Canada may host wind energy development in the near future. Design of the support structures for these projects is best performed through the use of an integrated tool that can calculate the cumulative effects of forces due to turbine operations, wind, waves, and floating ice. The dynamic nature of ice forces requires that these forces be included in the design simulations, rather than added as static forces to simulation results. The International Electrotechnical Commission (IEC) standard[2] for offshore wind turbine design and the International Organization for Standardization (ISO) standard[3] for offshore structures provide requirements and algorithms for the calculation of forces induced by surface ice; however, currently none of the major wind turbine dynamic simulation codes provides the ability to model ice loads. The scope of work of the project described in this report includes the development of a suite of subroutines, collectively named IceFloe, that meet the requirements of the IEC and ISO standards and couples with four of the major wind turbine dynamic simulation codes. The mechanisms by which ice forces impinge on offshore structures generally include the forces required for crushing of the ice against vertical-sided structures and the forces required to fracture the ice as it rides up on conical-sided structures. Within these two broad categories, the dynamic character of the forces with respect to time is also dependent on other factors such as the velocity and thickness of the moving ice and the response of the structure. In some cases, the dynamic effects are random and in other cases they are deterministic, such as the effect of structural resonance and coupling of the ice forces with the defection of the support structure. The initial versions of the IceFloe routines incorporate modules that address these varied force and dynamic phenomena with seven alternative algorithms that can be specified by the user. The IceFloe routines have been linked and tested with four major wind turbine aeroelastic simulation codes: FAST, a tool developed under the management of the National Renewable Energy Laboratory (NREL) and available free of charge from its web site; Bladed[4], a widely-used commercial package available from DNV GL; ADAMS[5], a general purpose multi-body simulation code used in the wind industry and available from MSC Software; and HAWC2[6], a code developed by and available for purchase from Danmarks Tekniske Universitet (DTU). Interface routines have been developed and tested with full wind turbine simulations for each of these codes and the source code and example inputs and outputs are available from the NREL website.

Download or read book Bottom Fixed Platform Dynamics Models Assessing Surface Ice Interactions for Transitional Depth Structures in the Great Lakes written by and published by . This book was released on 2015 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: To create long-term solutions for offshore wind turbines in a variety of environmental conditions, CAE tools are needed to model the design-driving loads that interact with an offshore wind turbine system during operation. This report describes our efforts in augmenting existing CAE tools used for offshore wind turbine analysis with a new module that can provide simulation capabilities for ice loading on the system. This augmentation was accomplished by creating an ice-loading module coupled to FAST8, the CAE tool maintained by the NREL for simulating land-based and offshore wind turbine dynamics. The new module includes both static and dynamic ice loading that can be applied during a dynamic simulation of the response of an offshore wind turbine. The ice forces can be prescribed, or influenced by the structure's compliant response, or by the dynamics of both the structure and the ice floe. The new module covers ice failure modes of spalling, buckling, crushing, splitting, and bending. The supporting structure of wind turbines can be modeled as a vertical or sloping form at the waterline. The Inward Battered Guide Structure (IBGS) foundation designed by Keystone Engineering for the Great Lakes was used to study the ice models coupled to FAST8. The IBGS foundation ice loading simulations in FAST8 were compared to the baseline simulation case without ice loading. The ice conditions reflecting those from Lake Huron at Port Huron and Lake Michigan at North Manitou were studied under near rated wind speed of 12 m/s for the NREL 5-MW reference turbine. Simulations were performed on ice loading models 1 through 4 and ice model 6 with their respective sub-models. The purpose of ice model 5 is to investigate ice loading on sloping structures such as ice-cones on a monopile and is not suitable for multi-membered jacketed structures like the IBGS foundation. The key response parameters from the simulations, shear forces and moments from the tower base and IBGS foundation base, were compared. Ice models 1 and 6 do not significantly affect the tower fore-aft shear and moment. However, ice model 2 (dynamic analyses), model 3 (random ice loading), and model 4 (multiple ice failure zone loading) show increased effect on the tower fore-aft shear and moment with significant effect from ice model 3.1. In general ice loading creates large reaction forces and moments at the base of the IBGS foundation; the largest occurred in model 1.1 (steady creep ice indentation loading) followed by model 3.1 (random creep ice indentation loading). In general the power production from the ice loading cases had little deviation from the baseline case without ice loading. For ultimate limit state (ULS), ice model 1.1 ice and 3.1 appear to be the ice most critical models to consider at an early stage of design. Ice model 4 is an important tool for assessing structural fatigue.

Download or read book Ultimate Toolbox written by Dawn Ibach and published by Alderac Entertainment Group (AEG). This book was released on 2009-09 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Our Island written by Children of Gununa and published by Penguin Group Australia. This book was released on 2014-04-30 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our island lies beneath a big blue sky, surrounded by the turquoise sea. Turtles glide through the clear salt water, and dugongs graze on banks of seagrass. In this lyrical celebration of place, the children of Mornington Islandexplore theirhome in words and pictures. This is a collaboration withmuch-loved children's picture-book creators authors Alison Lester and ElizabethHoney. All royalties from Our Island and one dollar from the sale of each copy are donated to Mornington Island State School to fund art projects in the community.

Download or read book Self Reflection Supplications written by Dilara Serkan and published by . This book was released on 2021-08-18 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our Lord! Let not our hearts deviate (from the truth) after You have guided us, and grant us mercy from You. Truly, You are the Bestower. (Surah Al-Imran - 3:8) This book allows you to identify how you are feeling and learn a supplication which will help overcome or battle that emotion. Whether you are feeling envy, happiness, hatred or laziness, this book can help provide a basis for your Duas and allow you to self-reflect on ways to handle these emotions in accordance with the Quran and Hadith. This book contains the dua in Arabic, with English transliteration and translation to allow readers to easily recall and memorise the true meaning behind different Duas.