Response of an Annular Tuned Liquid Damper Equipped With Damping Screens

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
K. P. McNamara ◽  
J. S. Love ◽  
M. J. Tait ◽  
T. C. Haskett
Keyword(s):  
Wind Turbine ◽  
Mechanical Model ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Tuned Liquid Damper ◽  
Equivalent Mechanical Model ◽  
Sloshing Mode ◽  
Force Excitation ◽  
Mode Response ◽  
Good Agreement

Abstract Annular tuned liquid dampers (TLDs) may be installed in slender structures with limited floor space, in which people and utilities must pass through the core, such as a wind turbine or observation tower. This study investigates an annular-shaped TLD equipped with damping screens. A linearized equivalent mechanical model capable of capturing the fundamental sloshing mode response of an annular TLD is presented. An experimental shake table testing program is completed to assess the performance of the model. Thirty-six frequency sweep tests consisting of various TLD configurations, excitation amplitudes, and excitation directions are completed. Good agreement is observed between the linearized equivalent mechanical model and experimental wave heights, sloshing forces, and energy dissipated per cycle that have been filtered to include only the fundamental sloshing mode response. The model is also observed to be in good agreement with experimental data for different excitation directions. The model is coupled to a generalized structure to investigate the response of a structure equipped with an annular TLD. The annular TLD is found to reduce the response of a generalized offshore wind turbine structure undergoing harmonic force excitation. The annular TLD provides performance comparable to an optimal linear tuned mass damper (TMD) with the same properties for a range of force excitation amplitudes.

Comparison of Dynamic Response in a 2MW Floating Offshore Wind Turbine During Typhoon Approaches

2019 ◽  
Author(s):  
Koji Tanaka ◽  
Iku Sato ◽  
Tomoaki Utsunomiya ◽  
Hiromu Kakuya
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Atmospheric Pressure ◽  
Offshore Wind ◽  
Floating Body ◽  
Offshore Wind Turbine ◽  
Floating Offshore Wind Turbine ◽  
Maximum Wave Height ◽  
Sea Area ◽  
Good Agreement

Abstract In this paper, we describe the analysis of the dynamic response of a 2 MW floating offshore wind turbine (FOWT) at the time of typhoon attack in the actual sea area. In order to introduce floating offshore wind turbine in Asia, it is essential to evaluate the influence of typhoon attack accurately. This FOWT, named HAENKAZE is the only FOWT to operate commercially in areas where typhoons occur. On July 3rd, 2018, the strongest typhoon (Prapiroon) at the installed area of the FOWT since its installation approached the HAENKAZE. The central atmospheric pressure of the typhoon at the closest time was 965 hPa, the maximum instantaneous wind speed at the hub height was 52.2 m/s, and the maximum wave height was 7.1 m. In this paper, the dynamic response of the floating body at the time of typhoon attack is compared for the measured and the simulated values. As a result of the comparison, basically a good agreement has been obtained between the measured and the simulated values except for yaw response, for which the simulated values considerably overestimate the measured values.

Modeling the Dynamics of Freely-Floating Offshore Wind Turbine Subjected to Waves With an Open-Source Overset Mesh Method

2021 ◽  
Author(s):  
Romain Pinguet ◽  
Sam Kanner ◽  
Michel Benoit ◽  
Bernard Molin
Keyword(s):  
Experimental Data ◽  
Wind Turbine ◽  
Open Source ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Wave Tank ◽  
Floating Offshore Wind Turbine ◽  
Mesh Method ◽  
Mesh Convergence ◽  
Good Agreement

Abstract The aim of this study is to develop a viscous numerical wave tank using a coupled solver between the wave generation and absorption toolbox waves2Foam, developed by Jacobsen et al. [1] and the overset method built in the open source CFD software OpenFOAM©. This wave tank can be used to analyze the behavior of Floating Offshore Wind Turbine (FOWT) in nonlinear waves. A mesh convergence analysis is presented on a simple 2D case in order to validate the CFD model. The results are compared to experimental data from the literature and show good agreement. The response of a floater developed for a FOWT is analyzed. The free surface elevation, heave and pitch motions are compared to experimental results from the literature. Comparisons between experimental data and numerical results are discussed.

scholarly journals Progress on the Development of a Holistic Coupled Model of Dynamics for Offshore Wind Farms: Phase II — Study on a Data-Driven Based Reduced-Order Model for a Single Wind Turbine

2019 ◽  
Author(s):  
Z. Lin ◽  
A. Stetco ◽  
J. Carmona-Sanchez ◽  
D. Cevasco ◽  
M. Collu ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Wind Farm ◽  
Coupled Model ◽  
Operating Conditions ◽  
Offshore Wind ◽  
Coupled Analysis ◽  
Offshore Wind Turbine ◽  
Reduced Order Models ◽  
Reduced Order ◽  
Good Agreement

Abstract At present, over 1500 offshore wind turbines (OWTs) are operating in the UK with a capacity of 5.4GW. Until now, the research has mainly focused on how to minimise the CAPEX, but Operation and Maintenance (O&M) can represent up to 39% of the lifetime costs of an offshore wind farm, mainly due to the assets’ high cost and the harsh environment in which they operate. Focusing on O&M, the HOME Offshore research project (www.homeoffshore.org) aims to derive an advanced interpretation of the fault mechanisms through holistic multiphysics modelling of the wind farm. With the present work, an advanced model of dynamics for a single wind turbine is developed, able to identify the couplings between aero-hydro-servo-elastic (AHSE) dynamics and drive train dynamics. The wind turbine mechanical components, modelled using an AHSE dynamic model, are coupled with a detailed representation of a variable-speed direct-drive 5MW permanent magnet synchronous generator (PMSG) and its fully rated voltage source converters (VSCs). Using the developed model for the wind turbine, several case studies are carried out for above and below rated operating conditions. Firstly, the response time histories of wind turbine degrees of freedom (DOFs) are modelled using a full-order coupled analysis. Subsequently, regression analysis is applied in order to correlate DOFs and generated rotor torque (target degree of freedom for the failure mode in analysis), quantifying the level of inherent coupling effects. Finally, the reduced-order multiphysics models for a single offshore wind turbine are derived based on the strength of the correlation coefficients. The accuracy of the proposed reduced-order models is discussed, comparing it against the full-order coupled model in terms of statistical data and spectrum. In terms of statistical results, all the reduced-order models have a good agreement with the full-order results. In terms of spectrum, all the reduced-order models have a good agreement with the full-order results if the frequencies of interest are below 0.75Hz.

Development of an Analysis Code of Rotor-Floater Coupled Response of a Floating Offshore Wind Turbine

2013 ◽  
Author(s):  
Hideyuki Suzuki ◽  
Hajime Shibata ◽  
Hiroyuki Fujioka ◽  
Shinichiro Hirabayashi ◽  
Kimiko Ishii ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Offshore Wind ◽  
Frame Structure ◽  
Offshore Wind Turbine ◽  
Response Analysis ◽  
Aerodynamic Load ◽  
Lumped Mass ◽  
Mass Model ◽  
Floating Offshore Wind Turbine ◽  
Good Agreement

Coupled rotor-floater response analysis is essentially important for the design of Rotor Nacelle Assembly (RNA) and floating support structure of Floating Offshore Wind Turbine (FOWT). The authors have developed an analysis code UTWind for analysis of the coupled structural response. Blades and floater are modeled as frame structure with beam elements. Lumped mass model is use for mooring. Aerodynamic load on blade is calculated by Blade Element Momentum Theory (BEM), and hydrodynamic load is calculated by Hooft’s method, and Morison equation was modified to be applicable to cylindrical element with cross section with two axes of lines symmetry. The equations of motion of rotor, floater and mooring are solved in time domain by weak coupling algorithm. The numerical results by the code were compared with responses measured by experiment in wave and wind-and-wave coexistence field with/without blade pitch control and showed good agreement. Response by negative damping was reproduced by the code and showed good agreement with experiments.

Verification of Engineering Modeling Tools for Floating Offshore Wind Turbines

2013 ◽  
Author(s):  
Tiago Duarte ◽  
David Tomas ◽  
Denis Matha ◽  
António Sarmento ◽  
Frieder Schuon
Keyword(s):  
Wind Turbine ◽  
Physical Models ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Floating Platform ◽  
Modeling Tools ◽  
Offshore Wind Turbines ◽  
Floating Offshore Wind Turbines ◽  
Engineering Modeling ◽  
Good Agreement

This paper presents a verification exercise with three different codes for floating offshore wind turbine modeling: FAST, S4WT and SIMPACK. The comparison showed good agreement in most of the results, and the main differences identified can largely be traced back to the different physical models used by the three simulation softwares. A detailed analysis of the wind turbine loads and motions is also included. FAST offered a greater computational efficiency compared with the other two softwares. Nevertheless, if one is interested in more detailed loads on blades, exact blade deflection predictions in bending and torsion, elastic effects of the floating platform etc., the more detailed codes S4WT and SIMPACK are beneficial.

scholarly journals A model for quick load analysis for monopile-type offshore wind turbine substructures

2018 ◽  
Vol 3 (1) ◽  
pp. 57-73 ◽  
Author(s):  
Signe Schløer ◽  
Laura Garcia Castillo ◽  
Morten Fejerskov ◽  
Emanuel Stroescu ◽  
Henrik Bredmose
Keyword(s):  
Wind Turbine ◽  
Load Condition ◽  
Structural Response ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Fatigue Load ◽  
Extreme Loads ◽  
Extreme Load ◽  
Load Analysis ◽  
Good Agreement

Abstract. A model for quick load analysis, QuLA, of an offshore wind turbine substructure is presented. The aerodynamic rotor loads and damping are pre-computed for a land-based configuration. The dynamic structural response is represented by the first global fore-aft mode only and is computed in the frequency domain with phases using the equation of motion. The model is compared to the state-of-the-art aeroelastic code Flex5. Both lifetime fatigue and extreme loads are considered in the comparison. In general there is good agreement between the two models. Some deviations for the sectional forces are explained in terms of the model simplifications. The differences in the sectional moments are found to be within 10 % for the fatigue load case and 10 % for the extreme load condition.

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