Numerical study of ice-induced loads and responses of a monopile-type offshore wind turbine in parked and operating conditions

Abstract Offshore wind is an attractive source of renewable energy. In regions with cold climates, such as Canada, the Baltic Sea, and Bohai Bay, a good understanding of ice loads is essential to design a reliable and cost effective support structure for an offshore wind turbine. This paper presents a study of the dynamic ice–structure interaction of a commonly used monopile-type offshore wind turbine in drifting level ice in both parked and operating conditions. A semi-empirical numerical model for ice–structure interaction was coupled to the aero-hydro-servo-elastic simulation tool HAWC2. A convergence study was performed to determine the proper time step and simulation length to obtain reliable response prediction. The simulated ice load was compared with the formulations in international standards. The coupling between the ice loads and the structural response of the monopile-type wind turbine was investigated and found to be important. The effects of the ice characteristics (e.g., ice thickness and drifting speed) were examined with the turbine being in parked and operating conditions. Compared with current numerical model, standards from International Electrotechnical Commission (IEC) and International Organization for Standardization (ISO) predict lower ice loads. 3-D effect of ice–monopile interaction and failure of local ice sheet are considered. More stochastic dynamic phenomena are captured for ice–structure interaction in our numerical model. The effect of the ice thickness on the response was found to be significant. A negligible drifting speed effect is found on the bending moment response in the fore-aft direction. There is a large increase in the fore-aft response as the inclination angle of the cone increases. Further sensitivity studies and validation against model tests will be performed for the conical waterline of the wind turbine.

[1]  Wei Shi,et al.  Offshore Code Comparison Collaboration Continuation Within IEA Wind Task 30: Phase II Results Regarding a Floating Semisubmersible Wind System , 2014 .

[2]  L. Tuomi,et al.  Wave hindcast statistics in the seasonally ice-covered Baltic Sea , 2011 .

[3]  Jinlin Hou,et al.  Structural Design for the Ice-Resistant Platform , 2014 .

[4]  T D Ralston,et al.  ICE FORCE DESIGN CONSIDERATIONS FOR CONICAL OFFSHORE STRUCTURES , 1977 .

[5]  W. Bai,et al.  Experimental study of wave-driven impact of sea ice floes on a circular cylinder , 2014 .

[6]  Torgeir Moan,et al.  Dynamic response analysis of wind turbines under blade pitch system fault, grid loss, and shutdown events , 2013 .

[7]  Kaj Riska.  Models of ice-structure contact for engineering applications , 1995 .

[8]  Martin Richard,et al.  Development of a Probabilistic Ice Load Model Based on Empirical Descriptions of High Pressure Zone Attributes , 2014 .

[9]  Garry Timco,et al.  Ice loading on Danish wind turbines: Part 2. Analyses of dynamic model test results , 2005 .

[10]  P. Spencer,et al.  Quantile Regression as a Tool for Investigating Local and Global Ice Pressures , 2014 .

[11]  Sanna Syri,et al.  What economic support is needed for Arctic offshore wind power , 2014 .

[12]  Chang-Wan Kim,et al.  A study on the effect of different modeling parameters on the dynamic response of a jacket-type offshore wind turbine in the Korean Southwest Sea , 2013 .

[13]  B. Balakin,et al.  Numerical Prediction of Contact Surface Between Hummock and Ice Fields for Estimation of Ice Loads on Structure , 2013 .

[14]  Hagbart S. Alsos,et al.  Estimates of the Number of Vibration Cycles From Frequency Locked-in Ice Loads , 2014 .

[15]  Jaakko Heinonen,et al.  Dynamic Ice Load Model In Overall Simulation of Offshore Wind Turbines , 2011 .

[16]  Dayong Zhang,et al.  Comparison and Cause Analysis of Ice-Induced Structural Vibrations on Different Ice-Breaking Cones , 2015 .

[17]  Torgeir Moan,et al.  Effect of dynamic bending of level ice on ship's continuous-mode icebreaking , 2014 .

[18]  Alexander T. Bekker,et al.  Estimation of Limit Ice Loads On Engineering Offshore Structures In the Sea of Okhotsk , 2009 .

[19]  Robert Frederking.  Comparison of Standards For Predicting Ice Forces On Arctic Offshore Structures , 2012 .

[20]  B Wright,et al.  Ice Load Measurement on Molikpaq: Methodology and Accuracy , 2011 .

[21]  Garry Timco,et al.  Ice loading on Danish wind turbines: Part 1: Dynamic model tests , 2005 .

[22]  Qianjin Yue,et al.  Dynamic Ice Force Analysis on a Conical Structure Based on Direct Observation and Measurement , 2014 .

[23]  Torgeir Moan,et al.  Wind turbine aerodynamic response under atmospheric icing conditions , 2014 .

[24]  Nand Kishor,et al.  Off-shore wind farm development: Present status and challenges , 2014 .

[25]  Tuomo Kärnä,et al.  Dynamic ice forces of slender vertical structures due to ice crushing , 2009 .

[26]  Jason Jonkman,et al.  Offshore Code Comparison Collaboration, Continuation: Phase II Results of a Floating Semisubmersible Wind System: Preprint , 2013 .

[27]  Torgeir Moan,et al.  Offshore Code Comparison Collaboration within IEA Wind Task 23: Phase IV Results Regarding Floating Wind Turbine Modeling; Preprint , 2010 .

[28]  Arne Gürtner,et al.  Numerical Simulation of Ice Action to a Lighthouse , 2009 .

[29]  J. Jonkman,et al.  Definition of a 5-MW Reference Wind Turbine for Offshore System Development , 2009 .

[30]  Andrei V. Metrikine,et al.  Analysis of the fatigue life of offshore wind turbine generators under combined ice- And aerodynamic loading , 2014 .

[31]  Denise Sudom,et al.  Conical structures in ice : The roles friction, slope and shape play , 2014 .

[32]  Li Jie.  Dynamic Response Analysis of Wind-excited Wind Turbine Systems , 2011 .

[33]  Sami Saarinen,et al.  Ice crushing tests with variable structural flexibility , 2011 .

[34]  Zhen Gao,et al.  Offshore code comparison collaboration continuation (OC4), phase I - Results of coupled simulations of an offshore wind turbine with jacket support structure , 2012 .

[35]  Dale G. Karr,et al.  Ice Nonsimultaneous Failure, Bending and Floe Impact Modeling for Simulating Wind Turbine Dynamics Using FAST , 2014 .

[36]  B Petersen,et al.  Ice Forces to Wind Turbine Foundations in Denmark , 2003 .

[37]  Michael Strobel,et al.  Introduction of ice loads in overall simulation of offshore wind turbines , 2011 .

[38]  Torgeir Moan,et al.  Study on the effect of ice-structure interaction on the dynamic response of a monopile offshore wind turbine , 2015 .

[39]  Kirill Sazonov,et al.  Analysis and Probabilistic Modeling of the Stationary Ice Loads Stochastic Process With Lognormal Distribution , 2014 .

[40]  Torgeir Moan,et al.  A six-degrees-of-freedom numerical model for level ice–ship interaction , 2013 .

[41]  Dale G. Karr,et al.  A Surface Ice Module for Wind Turbine Dynamic Response Simulation Using FAST , 2013 .

[42]  Wojciech Popko,et al.  State-of-the-art Comparison of Standards in Terms of Dominant Sea Ice Loads for Offshore Wind Turbine Support Structures in the Baltic Sea , 2012 .

[43]  M. Bjerkås,et al.  Ice Induced Vibrations - Observations of a Full Scale Lock-in Event , 2013 .

[44]  Ning Xu,et al.  Comparison and Cause Analysis of Ice-Induced Structural Vibration of Upward and Downward Cones , 2014 .

[45]  Torgeir Moan,et al.  Stochastic Dynamic Response Analysis of a Tension Leg Spar-Type Offshore Wind Turbine , 2013 .

[46]  Ian Baring-Gould,et al.  State-of-the-art of wind energy in cold climates , 2010 .

[47]  Torgeir Moan,et al.  A numerical method for the prediction of ship performance in level ice , 2010 .

[48]  Demian Battaglia,et al.  Deterministic and stochastic quantum annealing approaches , 2005 .

[49]  Ole Øiseth,et al.  Model-based force and state estimation in experimental ice-induced vibrations by means of Kalman filtering , 2015 .

[50]  John Murray,et al.  Model Tests on a Spar in Level Ice and Ice Ridge Conditions , 2009 .

[51]  Tuomo Kärnä,et al.  Mitigation of ice loading on off-shore wind turbines: Feasibility study of a semi-active solution , 2008 .

[52]  Torgeir Moan,et al.  Experiments on Level Ice Loading on an Icebreaking Tanker with Different Ice Drift Angles , 2013 .

[53]  Tuomo Kärnä,et al.  Ice Loads for Offshore Wind Turbines in Southern Baltic Sea , 2009 .