Articles | Volume 7, issue 3
https://doi.org/10.5194/wes-7-1021-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/wes-7-1021-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Review article
| 
17 May 2022
Review article |
| 17 May 2022
| 17 May 2022
Wind turbine main-bearing lubrication – Part 1: An introductory review of elastohydrodynamic lubrication theory
Wind Energy and Control Centre, Department of Electronic and Electrical Engineering, The University of Strathclyde, Glasgow, UK
Elisha de Mello
Leonardo Centre for Tribology, Department of Mechanical Engineering, The University of Sheffield, Sheffield, UK
Rob Dwyer-Joyce
Leonardo Centre for Tribology, Department of Mechanical Engineering, The University of Sheffield, Sheffield, UK
Related authors
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.
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.
James Stirling, Edward Hart, and Abbas Kazemi Amiri
Wind Energ. Sci., 6, 15–31, https://doi.org/10.5194/wes-6-15-2021, https://doi.org/10.5194/wes-6-15-2021, 2021
Short summary
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.
Edward Hart, Benjamin Clarke, Gary Nicholas, Abbas Kazemi Amiri, James Stirling, James Carroll, Rob Dwyer-Joyce, Alasdair McDonald, and Hui Long
Wind Energ. Sci., 5, 105–124, https://doi.org/10.5194/wes-5-105-2020, https://doi.org/10.5194/wes-5-105-2020, 2020
Short summary
Short summary
This paper presents a review of existing theory and practice relating to main bearings for wind turbines. Topics covered include wind conditions and resulting rotor loads, main-bearing models, damage mechanisms and fault detection procedures.
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.
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.
James Stirling, Edward Hart, and Abbas Kazemi Amiri
Wind Energ. Sci., 6, 15–31, https://doi.org/10.5194/wes-6-15-2021, https://doi.org/10.5194/wes-6-15-2021, 2021
Short summary
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.
Edward Hart, Benjamin Clarke, Gary Nicholas, Abbas Kazemi Amiri, James Stirling, James Carroll, Rob Dwyer-Joyce, Alasdair McDonald, and Hui Long
Wind Energ. Sci., 5, 105–124, https://doi.org/10.5194/wes-5-105-2020, https://doi.org/10.5194/wes-5-105-2020, 2020
Short summary
Short summary
This paper presents a review of existing theory and practice relating to main bearings for wind turbines. Topics covered include wind conditions and resulting rotor loads, main-bearing models, damage mechanisms and fault detection procedures.
Related subject area
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Modal dynamics of structures with bladed isotropic rotors and its complexity for two-bladed rotors
Emmanuel Branlard and Jens Geisler
Wind Energ. Sci., 7, 2351–2371, https://doi.org/10.5194/wes-7-2351-2022, https://doi.org/10.5194/wes-7-2351-2022, 2022
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The article presents a framework to obtain the linear and nonlinear equations of motion of a multibody system including rigid and flexible bodies. The method yields compact symbolic equations of motion. The applications are many, such as time-domain simulation, stability analyses, frequency domain analyses, advanced controller design, state observers, and digital twins.
Masaru Kitahara and Takeshi Ishihara
Wind Energ. Sci., 7, 1007–1020, https://doi.org/10.5194/wes-7-1007-2022, https://doi.org/10.5194/wes-7-1007-2022, 2022
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The seismic soil–structure interaction of wind turbine support structures is investigated. Wind turbine support structures are modelled as a non-classically damped system, and its seismic loadings are analytically derived by the response spectrum method. To improve the prediction accuracy of the shear force on the footing, a threshold for the allowable modal damping ratio is proposed. The proposed method is capable of effectively estimating seismic loadings on the tower and footing.
Pablo Noever-Castelos, David Melcher, and Claudio Balzani
Wind Energ. Sci., 7, 623–645, https://doi.org/10.5194/wes-7-623-2022, https://doi.org/10.5194/wes-7-623-2022, 2022
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In the wind energy industry, a digital twin is fast becoming a key instrument for the monitoring of a wind turbine blade's life cycle. Here, our introduced model updating with invertible neural networks provides an efficient and powerful technique to represent the real blade as built. This method is applied to a full finite element Timoshenko beam model of a blade to successfully update material and layup parameters. The advantage over state-of-the-art methods is the established inverse model.
Pablo Noever-Castelos, Bernd Haller, and Claudio Balzani
Wind Energ. Sci., 7, 105–127, https://doi.org/10.5194/wes-7-105-2022, https://doi.org/10.5194/wes-7-105-2022, 2022
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Modern rotor blade designs depend on detailed numerical models and simulations. Thus, a validated modeling methodology is fundamental for reliable designs. This paper briefly presents a modeling algorithm for rotor blades, its validation against real-life full-scale blade tests, and the respective test data. The hybrid 3D shell/solid finite-element model is successfully validated against the conducted classical bending tests in flapwise and lead–lag direction as well as novel torsion tests.
Peyman Amirafshari, Feargal Brennan, and Athanasios Kolios
Wind Energ. Sci., 6, 677–699, https://doi.org/10.5194/wes-6-677-2021, https://doi.org/10.5194/wes-6-677-2021, 2021
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One particular problem with structures operating in seas is the so-called fatigue phenomenon. Cyclic loads imposed by waves and winds can cause structural failure after a number of cycles. Traditional methods have some limitations.
This paper presents a developed design framework based on fracture mechanics for offshore wind turbine support structures which enables design engineers to maximise the use of available inspection capabilities and optimise the design and inspection, simultaneously.
James Stirling, Edward Hart, and Abbas Kazemi Amiri
Wind Energ. Sci., 6, 15–31, https://doi.org/10.5194/wes-6-15-2021, https://doi.org/10.5194/wes-6-15-2021, 2021
Short summary
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.
William Finnegan, Priya Dasan Keeryadath, Rónán Ó Coistealbha, Tomas Flanagan, Michael Flanagan, and Jamie Goggins
Wind Energ. Sci., 5, 1567–1577, https://doi.org/10.5194/wes-5-1567-2020, https://doi.org/10.5194/wes-5-1567-2020, 2020
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Leading edge erosion is an ever-existing damage issue on wind turbine blades. This paper presents the numerical finite element analysis model for incorporating a new leading edge protection component for offshore applications, which is manufactured from thermoplastic polyurethane, into wind turbine blade designs. The model has been validated against experimental trials at demonstrator level, comparing the deflection and strains during testing, and then applied to a full-scale wind turbine blade.
Can Muyan and Demirkan Coker
Wind Energ. Sci., 5, 1339–1358, https://doi.org/10.5194/wes-5-1339-2020, https://doi.org/10.5194/wes-5-1339-2020, 2020
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Wind turbine blade prototypes undergo structural tests before they are used in the field so that any design failure can be detected prior to their operation. In this study, strength characteristics of a small-scale existing 5 m composite wind turbine blade is carried out utilizing the finite-element-method software package Ansys. The results show that the blade exhibits sufficient resistance against buckling. Yet, laminate failure is found to play a major role in the ultimate blade failure.
Sven Störtenbecker, Peter Dalhoff, Mukunda Tamang, and Rudolf Anselm
Wind Energ. Sci., 5, 1121–1128, https://doi.org/10.5194/wes-5-1121-2020, https://doi.org/10.5194/wes-5-1121-2020, 2020
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Multi-rotor wind turbine systems show the potential to reduce the levelized cost of energy. In this study a simplified and fast method as a first venture to find an optimal number of rotors and design parameters is presented. A variety of space frame designs are dimensioned based on ultimate loads and buckling, as a preliminary step for later detailed analyses.
Giovanni Migliaccio, Giuseppe Ruta, Stefano Bennati, and Riccardo Barsotti
Wind Energ. Sci., 5, 685–698, https://doi.org/10.5194/wes-5-685-2020, https://doi.org/10.5194/wes-5-685-2020, 2020
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This work addresses the mechanical modelling of complex beamlike structures, which may be curved, twisted and tapered in their reference state and undergo large displacements, 3D cross-sectional warping and small strains. A model suitable for the problem at hand is proposed. It can be used to analyze large deflections under prescribed loads and determine the stress and strain fields in the structure. Analytical and numerical results obtained by applying the proposed modelling approach are shown.
David Melcher, Moritz Bätge, and Sebastian Neßlinger
Wind Energ. Sci., 5, 675–684, https://doi.org/10.5194/wes-5-675-2020, https://doi.org/10.5194/wes-5-675-2020, 2020
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When a new rotor blade is designed, a prototype needs to be qualified by testing in two separate directions before it can be used in the field. These tests are time-consuming and expensive. Combining these two tests into one by applying loads in two directions simultaneously is a possible method to reduce time and costs. This paper presents a new computational method, which is capable of designing these complex tests and shows exemplarily that the combined test is faster than traditional tests.
Ozan Gözcü and David R. Verelst
Wind Energ. Sci., 5, 503–517, https://doi.org/10.5194/wes-5-503-2020, https://doi.org/10.5194/wes-5-503-2020, 2020
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Geometrically nonlinear blade modeling effects on the turbine loads and computation time are investigated in an aero-elastic code based on multibody formulation. A large number of fatigue load cases are used in the study. The results show that the nonlinearities become prominent for large and flexible blades. It is possible to run nonlinear models without significant increase in computational time compared to the linear model by changing the matrix solver type from dense to sparse.
Edward Hart, Benjamin Clarke, Gary Nicholas, Abbas Kazemi Amiri, James Stirling, James Carroll, Rob Dwyer-Joyce, Alasdair McDonald, and Hui Long
Wind Energ. Sci., 5, 105–124, https://doi.org/10.5194/wes-5-105-2020, https://doi.org/10.5194/wes-5-105-2020, 2020
Short summary
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This paper presents a review of existing theory and practice relating to main bearings for wind turbines. Topics covered include wind conditions and resulting rotor loads, main-bearing models, damage mechanisms and fault detection procedures.
Evgueni Stanoev and Sudhanva Kusuma Chandrashekhara
Wind Energ. Sci., 4, 57–69, https://doi.org/10.5194/wes-4-57-2019, https://doi.org/10.5194/wes-4-57-2019, 2019
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In the frame of a multi-body simulation of a wind turbine, the lowest rotor blade eigenmodes are used to describe their elastic deformations. In this paper, a finite Timoshenko beam element is proposed based on the transfer matrix method. The element stiffness and mass matrices are derived by numerical integration of the differential equations of motion. A numerical example with generic rotor blade data demonstrates the performance of the method in comparison with FAST/ADAMS software results.
Dominik Traphan, Iván Herráez, Peter Meinlschmidt, Friedrich Schlüter, Joachim Peinke, and Gerd Gülker
Wind Energ. Sci., 3, 639–650, https://doi.org/10.5194/wes-3-639-2018, https://doi.org/10.5194/wes-3-639-2018, 2018
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Wind turbines are exposed to harsh weather, leading to surface defects on rotor blades emerging from the first day of operation. Defects
grow quickly and affect the performance of wind turbines. Thus, there is demand for an easily applicable remote-inspection method that is sensitive to small
surface defects. In this work we show that infrared thermography can meet these requirements by visualizing differences in the surface temperature
of the rotor blades downstream of surface defects.
Jake D. Nunemaker, Michael M. Voth, David A. Miller, Daniel D. Samborsky, Paul Murdy, and Douglas S. Cairns
Wind Energ. Sci., 3, 427–438, https://doi.org/10.5194/wes-3-427-2018, https://doi.org/10.5194/wes-3-427-2018, 2018
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This paper presents an experimental investigation of the tensile strength of fiberglass–epoxy composites before and after water saturation. The strengths of [0], [90], and [0/90] layups all show a drop in tensile strength. However, investigation of the data, damaged coupons, and acoustic emission events illustrates a change in the mechanism governing final failure between the dry and saturated coupons. This illustrates the complexity of strength prediction of multiple layups after saturation.
Malo Rosemeier, Gregor Basters, and Alexandros Antoniou
Wind Energ. Sci., 3, 163–172, https://doi.org/10.5194/wes-3-163-2018, https://doi.org/10.5194/wes-3-163-2018, 2018
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This research was conducted with the help of computer models to give argumentation on how the reliability of wind turbine rotor blade structures can be increased using subcomponent testing (SCT) as a supplement to full-scale blade testing (FST). It was found that the use of SCT can significantly reduce the testing time compared to FST while replicating more realistic loading conditions for an outboard blade segment as it occurs in the field.
Matthias Stammler, Fabian Schwack, Norbert Bader, Andreas Reuter, and Gerhard Poll
Wind Energ. Sci., 3, 97–105, https://doi.org/10.5194/wes-3-97-2018, https://doi.org/10.5194/wes-3-97-2018, 2018
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Modern wind turbines all share the ability to turn (pitch) the blades around their main axis. By pitching the blades, the aerodynamic forces created by the blades are controlled. Rolling bearings, consisting of two steel rings and balls that roll on raceways between them, are used to allow pitching. To design pitch drives, it is necessary to know the losses within the bearings. This article describes how such losses have been measured and compares them with calculation models.
Jared W. Nelson, Trey W. Riddle, and Douglas S. Cairns
Wind Energ. Sci., 2, 641–652, https://doi.org/10.5194/wes-2-641-2017, https://doi.org/10.5194/wes-2-641-2017, 2017
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Given the rapid growth and large scale of wind turbines, it is important that wind farms achieve maximum availability by reducing downtime due to maintenance and failures. The Blade Reliability Collaborative, led by Sandia National Laboratories and sponsored by the US DOE, was formed to address this issue. A comprehensive study to characterize and understand the manufacturing flaws common in blades, and their impact on blade life, was performed by measuring and testing commonly included defects.
Jared W. Nelson, Trey W. Riddle, and Douglas S. Cairns
Wind Energ. Sci., 2, 653–669, https://doi.org/10.5194/wes-2-653-2017, https://doi.org/10.5194/wes-2-653-2017, 2017
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The Blade Reliability Collaborative was formed to address wind turbine blade reliability. To better understand and predict these effects, various progressive damage modeling approaches, built upon the characterization previously addressed, were investigated. The results indicate that a combined continuum–discrete approach provides insight into reliability with known defects when used in conjunction with a probabilistic flaw framework.
Morten Hartvig Hansen
Wind Energ. Sci., 1, 271–296, https://doi.org/10.5194/wes-1-271-2016, https://doi.org/10.5194/wes-1-271-2016, 2016
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The modal dynamics of wind turbines are the fingerprints of their responses under the stochastic excitation from the wind field. Commercial wind turbines have typically three-bladed rotors, and their modal dynamics are well understood. Two-bladed turbines are still commercially less successful, and this work also shows that their modal dynamics are significantly more complex than that of turbines with three or more blades.
Cited articles
Albahrani, S., Philippon, D., Vergne, P., and Bluet, J.: A review of in situ
methodologies for studying elastohydrodynamic lubrication, Proc. Institut. Mech. Eng. Pt. J, 230, 86–110, 2016. a
Antoine, J.-F., Visa, C., Sauvey, C., and Abba, G.: Approximate Analytical
Model for Hertzian Elliptical Contact Problems, J. Tribol., 128, 660–664, https://doi.org/10.1115/1.2197850, 2006. a
ASTM: D341 – 20e1 Standard Practice for Viscosity-Temperature Equations and Charts for Liquid Petroleum or Hydrocarbon Products, Standard, ASTM International, West Conshohocken, PA, https://doi.org/10.1520/D0341-20E01, 2020. a, b
Bair, S.: An experimental verification of the significance of the reciprocal
asymptotic isoviscous pressure for EHD lubricants, Tribol. Transact., 36, 153–162, 1993.
Brewe, D. and Hamrock, B.: Simplified Solution for Elliptical-Contact
Deformation Between Two Elastic Solids, J. Lubricat. Tech., 99, 485–487, 1977. a
Cann, P.: Starvation and reflow in a grease-lubricated elastohydrodynamic
contact, Tribol. Transact., 39, 698–704, 1996. a
Cann, P., Williamson, B., Coy, R., and Spikes, H.: The behaviour of greases in elastohydrodynamic contacts, J. Phys. D, 25, A124, https://doi.org/10.1088/0022-3727/25/1A/020, 1992. a
Cousseau, T., Björling, M., Graça, B., Campos, A., Seabra, J., and
Larsson, R.: Film thickness in a ball-on-disc contact lubricated with greases, bleed oils and base oils, Tribol. Int., 53, 53–60, 2012. a
Dlugoš, J. and Novotnỳ, P.: Effective Implementation of Elastohydrodynamic Lubrication of Rough Surfaces into Multibody Dynamics
Software, Appl. Sci., 11, 1488, https://doi.org/10.1016/j.triboint.2019.106064, 2021. a
Dowson, D.: A generalized Reynolds equation for fluid-film lubrication, Int. J. Mech. Sci., 4, 159–170, 1962. a
Dowson, D. and Higginson, G.: A numerical solution to the elasto-hydrodynamic
problem, J. Mech. Eng. Sci., 1, 6–15, 1959. a
Gao, M., Liang, H., Wang, W., and Chen, H.: Oil redistribution and
replenishment on stationary bearing inner raceway, Tribol. Int., 165, 107315, https://doi.org/10.1016/j.triboint.2021.107315, 2022. a
Goksem, P. and Hargreaves, R.: The effect of viscous shear heating on both film thickness and rolling traction in an EHL line contact – Part II: Starved conditions, J. Lubricat. Tech., 100, 353–358, 1978. a
Greenwood, J.: An extension of the Grubin theory of elastohydrodynamic
lubrication, J. Phys. D, 5, 2195, https://doi.org/10.1088/0022-3727/5/12/309, 1972. a
Greenwood, J. A.: Elastohydrodynamic lubrication, Lubricants, 8, 51, https://doi.org/10.3390/lubricants8050051, 2020. a
Guo, Y., Bankestrom, O., Bergua, R., Keller, J., and Dunn, M.: Investigation of main bearing operating conditions in a three-Point mount wind turbine
drivetrain, Forschung im Ingenieurwesen, 85, 405–415, 2021. a
Habchi, W.: Finite element modeling of elastohydrodynamic lubrication problems, John Wiley & Sons Ltd., ISBN 978-1-119-22512-6, 2018. a
Habchi, W. and Vergne, P.: A Quantitative Determination of Minimum Film
Thickness in Elastohydrodynamic Circular Contacts, Tribol. Lett., 69, 1–12, 2021. a
Habchi, W., Eyheramendy, D., Vergne, P., and Morales-Espejel, G.: A full-system approach of the elastohydrodynamic line/point contact problem, J. Tribol., 130, 021501, https://doi.org/10.1115/1.2842246, 2008. a
Hamrock, B. J. and Dowson, D.: Isothermal elastohydrodynamic lubrication of
point contacts: Part IV – starvation results, J. Lubricat. Tech., 99, 15–23, 1977b. a
Hart, E., Turnbull, A., Feuchtwang, J., McMillan, D., Golysheva, E., and
Elliott, R.: Wind turbine main-bearing loading and wind field
characteristics, Wiley Wind Energy, 22, 1534–1547, https://doi.org/10.1002/we.2386,
2019. a
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
Holmes, M., Evans, H., Hughes, T., and Snidle, R.: Transient elastohydrodynamic point contact analysis using a new coupled differential deflection method part 1: theory and validation, Proc. Institut. Mech. Eng. Pt. J, 217, 289–304, 2003. a
Hooke, C.: A review of the paper “A numerical solution to the elastohydrodynamic problem” by D. Dowson and GR Higginson, Proc. Institut. Mech. Eng. Pt. C, 223, 49–63, 2009. a
Huang, L., Guo, D., Liu, X., Xie, G., Wan, G. T., and Wen, S.: Effects of nano thickener deposited film on the behaviour of starvation and replenishment of lubricating greases, Friction, 4, 313–323, 2016. a
Hughes, T., Elcoate, C., and Evans, H.: Coupled solution of the
elastohydrodynamic line contact problem using a differential deflection
method, Proc. Institut. Mech. Eng. Pt. C, 214, 585–598, 2000. a
Hurley, S. and Cann, P.: IR spectroscopic analysis of grease lubricant films in rolling contacts, in: Tribology Series, vol. 36, Elsevier, 589–600,
https://doi.org/10.1016/S0167-8922(99)80079-0, 1999. a
Lubrecht, A., Venner, C. H., and Colin, F.: Film thickness calculation in
elasto-hydrodynamic lubricated line and elliptical contacts: the Dowson,
Higginson, Hamrock contribution, Proc. Institut. Mech. Eng. Pt. J, 223,
511–515, 2009. a
Mihailidis, A., Agouridas, K., and Panagiotidis, K.: Non-Newtonian starved
thermal-elastohydrodynamic lubrication of finite line contacts, Tribol. Transact., 56, 88–100, 2013. a
Morales-Espejel, G.: Central film thickness in time-varying normal approach of rolling elastohydrodynamically lubricated contacts, Proc. Institut. Mech. Eng. Pt. C, 222, 1271–1280, 2008. a
Nejad, A. R., Keller, J., Guo, Y., Sheng, S., Polinder, H., Watson, S., Dong, J., Qin, Z., Ebrahimi, A., Schelenz, R., Gutiérrez Guzmán, F., Cornel, D., Golafshan, R., Jacobs, G., Blockmans, B., Bosmans, J., Pluymers, B., Carroll, J., Koukoura, S., Hart, E., McDonald, A., Natarajan, A., Torsvik, J., Moghadam, F. K., Daems, P.-J., Verstraeten, T., Peeters, C., and Helsen, J.: Wind turbine drivetrains: state-of-the-art technologies and future development trends, Wind Energ. Sci., 7, 387–411, https://doi.org/10.5194/wes-7-387-2022, 2022. a
Panton, R.: Incompressible Flow, in: chap. 22 “Lubrication Approximation”, 4th Edn., John Wiley & Sons, ISBN: 978-1-118-41573-3, 2013. a
Popovici, G., Venner, C. H., and Lugt, P.: Effects of load system dynamics on
the film thickness in EHL contacts during start up, J. Tribol., 126, 258–266, 2004. a
Rolink, A., Schröder, T., Jacobs, G., Bosse, D., Hölzl, J., and
Bergmann, P.: Feasibility study for the use of hydrodynamic plain bearings
with balancing support characteristics as main bearing in wind turbines, J. Phys.: Conf. Ser., 1618, 052002, https://doi.org/10.1088/1742-6596/1618/5/052002, 2020. a
Rolink, A., Jacobs, G., Schröder, T., Keller, D., Jakobs, T., Bosse, D.,
Lang, J., and Knoll, G.: Methodology for the systematic design of conical
plain bearings for use as main bearings in wind turbines, Forschung Ingenieurwesen, 85, 629–637, 2021. a
Sugimura, J., Okumura, T., Yamamoto, Y., and Spikes, H.: Simple equation for
elastohydrodynamic film thickness under acceleration, Tribol. Int. 32, 117–123, 1999. a
Tsuha, N. A. H. and Cavalca, K. L.: Finite line contact stiffness under
elastohydrodynamic lubrication considering linear and nonlinear force models,
Tribol. Int., 146, 106219, https://doi.org/10.1016/j.triboint.2020.106219, 2020. a, b
Van Zoelen, M., Venner, C. H., and Lugt, P.: Free surface thin layer flow on
bearing raceways, J. Tribol., 130, 021802, https://doi.org/10.1115/1.2805433, 2008. a
Van Zoelen, M. T., Venner, C. H., and Lugt, P. M.: Free surface thin layer flow in bearings induced by centrifugal effects, Tribol. Transact., 53,
297–307, 2010. a
Venner, C.: Higher-Order Multilevel Solvers for the EHL Line and Point Contact Problem, J. Tribol., 4, 741–750, https://doi.org/10.1115/1.2927328, 1994. a
Venner, C. and Bos, J.: Effects of lubricant compressibility on the film
thickness in EHL line and circular contacts, Wear, 173, 151–165, 1994. a
Venner, C. and Lubrecht, A.: Multigrid techniques: A fast and efficient method for the numerical simulation of elastohydrodynamically lubricated point contact problems, Proc. Institut. Mech. Eng. Pt. J, 214, 43–62,
https://doi.org/10.1243/1350650001543007, 2000a. a
Venner, C. and Lubrecht, A.: Multi-level methods in lubrication, Elsevier,
ISBN 9780444505033, 2000b. a
Vergne, P. and Bair, S.: Classical EHL versus quantitative EHL: a perspective
part I – real viscosity-pressure dependence and the viscosity-pressure
coefficient for predicting film thickness, Tribol. Lett., 54, 1–12, 2014. a
Wheeler, J., Fillot, N., Vergne, P., Philippon, D., and Morales-Espejel, G.: On the crucial role of ellipticity on elastohydrodynamic film thickness and
friction, Proc. Institut. Mech. Eng. Pt. J, 230, 1503–1515, 2016a. a
Zhang, X. and Glovnea, R.: An experimental investigation of grease lubricated
EHD contact subjected to normal sinusoidally variable loading, Tribol. Int., 147, 106272, https://doi.org/10.1016/j.triboint.2020.106272, 2020. a
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.
This work provides an accessible introduction to elastohydrodynamic lubrication theory as a...
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