Articles | Volume 6, issue 1
https://doi.org/10.5194/wes-6-15-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Special issue:
https://doi.org/10.5194/wes-6-15-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Constructing fast and representative analytical models of wind turbine main bearings
James Stirling
CORRESPONDING AUTHOR
Wind and Marine Energy Systems CDT, EEE, University of Strathclyde, Glasgow, UK
Edward Hart
Wind Energy and Control Centre, EEE, University of Strathclyde, Glasgow, UK
Abbas Kazemi Amiri
Wind Energy and Control Centre, EEE, University of Strathclyde, Glasgow, UK
Related authors
No articles found.
Piotr Fojcik, Edward Hart, and Emil Hedevang
Wind Energ. Sci., 10, 1943–1962, https://doi.org/10.5194/wes-10-1943-2025, https://doi.org/10.5194/wes-10-1943-2025, 2025
Short summary
Short summary
Increasing the efficiency of wind farms can be achieved via reducing the impact of wakes – flow regions with lower wind speed occurring downwind from turbines. This work describes training and validation of a novel method for the estimation of the wake effects impacting a turbine. The results show that for most tested wind conditions, the developed model is capable of robust detection of wake presence and accurate characterisation of its properties. Further validation and improvements are planned.
Edward Hart
Wind Energ. Sci., 10, 1821–1827, https://doi.org/10.5194/wes-10-1821-2025, https://doi.org/10.5194/wes-10-1821-2025, 2025
Short summary
Short summary
A parametric model for the wind direction rose is presented, with testing on real offshore wind farm data indicating that the model performs well. The presented model provides opportunities for standardisation and enables more systematic analyses of wind direction distribution impacts and sensitivities.
Julian Quick, Edward Hart, Marcus Binder Nilsen, Rasmus Sode Lund, Jaime Liew, Piinshin Huang, Pierre-Elouan Rethore, Jonathan Keller, Wooyong Song, and Yi Guo
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2025-63, https://doi.org/10.5194/wes-2025-63, 2025
Revised manuscript under review for WES
Short summary
Short summary
Wind turbine main bearings often fail prematurely, creating costly maintenance challenges. This study examined how wake effects – where upstream turbines create disturbed airflow that impacts downstream turbines – affect bearing lifespans. Using computer simulations, we found that wake effects reduce bearing life by 16% on average. The direction of wake impact matters significantly due to interactions between wind forces and gravity, informing better wind turbine and farm farm design strategies.
Laurence Morgan, Abbas Kazemi Amiri, William Leithead, and James Carroll
Wind Energ. Sci., 10, 381–399, https://doi.org/10.5194/wes-10-381-2025, https://doi.org/10.5194/wes-10-381-2025, 2025
Short summary
Short summary
This paper presents a systematic study of the effect of blade inclination angle, chord distribution, and blade length on vertical-axis wind turbine performance. It shows that, for rotors of identical power production, both blade volume and rotor torque can be significantly reduced through the use of aerodynamically optimised inclined rotor blades. This demonstrates the potential of vertical rotors to reduce the cost of energy for offshore wind when compared to horizontal rotors.
Scott Dallas, Adam Stock, and Edward Hart
Wind Energ. Sci., 9, 841–867, https://doi.org/10.5194/wes-9-841-2024, https://doi.org/10.5194/wes-9-841-2024, 2024
Short summary
Short summary
This review presents the current understanding of wind direction variability in the context of control-oriented modelling of wind turbines and wind farms in a manner suitable to a wide audience. Motivation comes from the significant and commonly seen yaw error of horizontal axis wind turbines, which carries substantial negative impacts on annual energy production and the levellised cost of wind energy. Gaps in the literature are identified, and the critical challenges in this area are discussed.
Edward Hart, Elisha de Mello, and Rob Dwyer-Joyce
Wind Energ. Sci., 7, 1533–1550, https://doi.org/10.5194/wes-7-1533-2022, https://doi.org/10.5194/wes-7-1533-2022, 2022
Short summary
Short summary
This paper is the second in a two-part study on lubrication in wind turbine main bearings. Investigations are conducted concerning lubrication in the double-row spherical roller main bearing of a 1.5 MW wind turbine. This includes effects relating to temperature, starvation, grease-thickener interactions and possible non-steady EHL effects. Results predict that the modelled main bearing would be expected to operate under mixed lubrication conditions for a non-negligible proportion of its life.
Edward Hart, Adam Stock, George Elderfield, Robin Elliott, James Brasseur, Jonathan Keller, Yi Guo, and Wooyong Song
Wind Energ. Sci., 7, 1209–1226, https://doi.org/10.5194/wes-7-1209-2022, https://doi.org/10.5194/wes-7-1209-2022, 2022
Short summary
Short summary
We consider characteristics and drivers of loads experienced by wind turbine main bearings using simplified models of hub and main-bearing configurations. Influences of deterministic wind characteristics are investigated for 5, 7.5, and 10 MW turbine models. Load response to gusts and wind direction changes are also considered. Cubic load scaling is observed, veer is identified as an important driver of load fluctuations, and strong links between control and main-bearing load response are shown.
Edward Hart, Elisha de Mello, and Rob Dwyer-Joyce
Wind Energ. Sci., 7, 1021–1042, https://doi.org/10.5194/wes-7-1021-2022, https://doi.org/10.5194/wes-7-1021-2022, 2022
Short summary
Short summary
This work provides an accessible introduction to elastohydrodynamic lubrication theory as a precursor to analysis of lubrication in a wind turbine main bearing. Fundamental concepts, derivations and formulas are presented, followed by the more advanced topics of starvation, non-steady effects, surface roughness interactions and grease lubrication.
Amir R. Nejad, Jonathan Keller, Yi Guo, Shawn Sheng, Henk Polinder, Simon Watson, Jianning Dong, Zian Qin, Amir Ebrahimi, Ralf Schelenz, Francisco Gutiérrez Guzmán, Daniel Cornel, Reza Golafshan, Georg Jacobs, Bart Blockmans, Jelle Bosmans, Bert Pluymers, James Carroll, Sofia Koukoura, Edward Hart, Alasdair McDonald, Anand Natarajan, Jone Torsvik, Farid K. Moghadam, Pieter-Jan Daems, Timothy Verstraeten, Cédric Peeters, and Jan Helsen
Wind Energ. Sci., 7, 387–411, https://doi.org/10.5194/wes-7-387-2022, https://doi.org/10.5194/wes-7-387-2022, 2022
Short summary
Short summary
This paper presents the state-of-the-art technologies and development trends of wind turbine drivetrains – the energy conversion systems transferring the kinetic energy of the wind to electrical energy – in different stages of their life cycle: design, manufacturing, installation, operation, lifetime extension, decommissioning and recycling. The main aim of this article is to review the drivetrain technology development as well as to identify future challenges and research gaps.
Cited articles
Artigao, E., Martín-Martínez, S., Honrubia-Escribano, A., and
Gómez-Lázaro, E.: Wind turbine reliability: A comprehensive review towards effective condition monitoring development, Appl. Energy, 228, 1569–1583, https://doi.org/10.1016/j.apenergy.2018.07.037, 2018. a
Bosmans, J., Blockmans, B., Croes, J., Vermaut, M., and Desmet, W.: 1D–3D
Nesting: Embedding reduced order flexible multibody models in system-level
wind turbine drivetrain models, in: Conference for Wind Power Drives, 12–13 March 2019, Aachen, 523–537, 2019. a
Cardaun, M., Roscher, B., Schelenz, R., and Jacobs, G.: Analysis of
wind-turbine main bearing loads due to constant yaw misalignments over a 20 years timespan, Energies, 12, 1768, https://doi.org/10.3390/en12091768, 2019. a
Dowson, D. and Higginson, G. R.: Elastohydrodynamic Lubrication – Chapter 12, in: vol. 23, Pergamon Press Ltd., Oxford, England, 1977. a
Girsang, I. P., Dhupia, J. S., Muljadi, E., Singh, M., and Pao, L. Y.: Gearbox and drivetrain models to study dynamic effects of modern wind turbines, IEEE T. Indust. Appl., 50, 3777–3786, https://doi.org/10.1109/TIA.2014.2321029, 2014.
a
Harris, T. A.: Essential Concepts of Bearing Technology, 5th Edn., CRC Press, Boca Raton, Florida, https://doi.org/10.1201/9781420006599, 2006. a
Hart, E.: Developing a systematic approach to the analysis of time-varying main-bearing loads for wind turbines, Wind Energy, 23, 2150–2165, https://doi.org/10.1002/we.2549, 2020. a, b
Hart, E., Clarke, B., Nicholas, G., Kazemi Amiri, A., Stirling, J., Carroll, J., Dwyer-Joyce, R., McDonald, A., and Long, H.: A review of wind turbine main bearings: design, operation, modelling, damage mechanisms and fault detection, Wind Energ. Sci., 5, 105–124, https://doi.org/10.5194/wes-5-105-2020, 2020. a, b
Hibbeler, R.: Structural Analysis, Pearson Education, University of Louisiana, Lafayette, 2011. a
Junginger, M., Faaij, A., and Turkenburg, W. C.: Cost Reduction Prospects for
Offshore Wind Farms, Wind Eng., 28, 97–118, 2004. a
Keller, J., Shend, S., Cotrell, J., and Greco, A.: Wind turbine drivetrain reliability collaborative workshop: a recap, Tech. rep., US Department
of Energy, available at: https://www.researchgate.net/publication/307511892 (last access: 23 December 2020), 2016. a
Kock, S., Jacobs, G., and Bosse, D.: Determination of Wind Turbine Main Bearing Load Distribution, J. Phys.: Conf. Ser., 1222, 012030, https://doi.org/10.1088/1742-6596/1222/1/012030, 2019. a, b
Leet, K. C. and Uang, A. G.: Fundamentals of Structural Analysis, McGraw Hill, Boston, 2011. a
Popov, E. P.: Engineering Mechanics of solids, Prentice-Hall Inc., Upper Saddle River, NJ, 1990. a
Sethuraman, L., Guo, Y., and Sheng, S.: Main Bearing Dynamics in Three-Point
Suspension Drivetrains for Wind Turbines, in: American wind energy association windpower, 18–21 May 2015, Orlando, Florida, 2015. a
Sinha, Y. and Steel, J. A.: A progressive study into offshore wind farm
maintenance optimisation using risk based failure analysis, Renew. Sustain. Energ. Rev., 42, 735–742, https://doi.org/10.1016/j.rser.2014.10.087, 2015. a
Smalley, J.: Turbine components: bearings, available at:
http://www.windpowerengineering.com/design/mechanical
(last access: 5 April 2019), 2015. a
Tavner, P. J., Xiang, J., and Spinato, F.: Reliability analysis for wind
turbines, Wind Energy, 10, 1–18, https://doi.org/10.1002/we.204, 2007. a
Tibbits, P. A.: Fem simulation and life optimization of tandem roller thrust
bearing, in: Proceedings of the ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference – DETC2005, 3 A, 24–28 September 2005, Long Beach, California, USA, 79–88, https://doi.org/10.1115/detc2005-84234, 2005. a
UK Government: Contracts for Difference Second Allocation Round Results,
Tech. Rep. September, UK Government, 2017. a
Wang, S., Nejad, A. R., Bachynski, E. ., and Moan, T.: Effects of bedplate
flexibility on drivetrain dynamics: Case study of a 10 MW spar type floating
wind turbine, Renew. Energy, 161, 808–824, https://doi.org/10.1016/j.renene.2020.07.148, 2020a. a, b
Wang, S., Nejad, A. R., and Moan, T.: On design, modelling, and analysis of a
10-MW medium-speed drivetrain for offshore wind turbines, Wind Energy, 23,
1099–1117, https://doi.org/10.1002/we.2476, 2020b. a
Wilkinson, M.: Measuring Wind Turbine Reliability – Results of the Reliawind
Project, Tech. rep., GL Garrad Hassan, St Vincent's Works, Bristol, UK, https://doi.org/10.11333/jwea.35.2_102, 2011.
a
Wind Europe: Wind Energy in Europe in 2019, Tech. rep., Wind Europe, available at:
https://windeurope.org/wp-content/uploads/files/about-wind/statistics/WindEurope-Annual-Statistics-2019.pdf
(last access: 26 February 2019), 2020. a
Yagi, S.: Bearings for Wind Turbine, 71, NTN Technical review, NTN, 40–47, 2004. a
Short summary
This paper considers the modelling of wind turbine main bearings using analytical models. The validity of simplified analytical representations is explored by comparing main-bearing force reactions with those obtained from higher-fidelity 3D finite-element models. Results indicate that good agreement can be achieved between the analytical and 3D models in the case of both non-moment-reacting (such as for a spherical roller bearing) and moment-reacting (such as a tapered roller bearing) set-ups.
This paper considers the modelling of wind turbine main bearings using analytical models. The...
Special issue
Altmetrics
Final-revised paper
Preprint