0
Research Papers

Description and Computer Modeling of a Ball-and-Socket Hub That Enables Teetering for Three-Bladed Wind Turbines

[+] Author and Article Information
Arnold Ramsland

Ramsland Technology,
97533 Franklin Ridge,
Chapel Hill, NC 27517
e-mail: acrbjr@msn.com

Contributed by the Solar Energy Division of ASME for publication in the JOURNAL OF SOLAR ENERGY ENGINEERING: INCLUDING WIND ENERGY AND BUILDING ENERGY CONSERVATION. Manuscript received May 20, 2014; final manuscript received February 4, 2015; published online March 12, 2015. Assoc. Editor: Yves Gagnon.

J. Sol. Energy Eng 137(3), 031019 (Jun 01, 2015) (12 pages) Paper No: SOL-14-1152; doi: 10.1115/1.4029813 History: Received May 20, 2014; Revised February 04, 2015; Online March 12, 2015

A horizontal axis wind turbine with a ball-and-socket hub is disclosed. The hub enables horizontal axis turbines with two or more blades to teeter in response to wind shear gradients. Computer modeling was done using existing and modified fast code in order to compare the new hub design with existing designs. Results show that a three-bladed turbine with the ball-and-socket hub provides very significant reductions in out-of-plane bending loads applied to the main shaft in comparison to a three-bladed turbine with a rigid hub. Results also show that the new hub design provides significant reductions in the out-of-plane loads applied to the blades. A blade fatigue study using a rainflow counting of multi-axial torque contributions at the blade root was performed in order to assess the impact of these reductions, and results show that the three-bladed turbine equipped with a ball-and-socket, teetering hub provides for very significant reductions in lifetime blade damage in comparison to existing wind turbine designs due to a combination of factors. The first factor is that teetering largely eliminates the cyclic variations in out-of-plane torque on the blades that are observed with rigid hubs. Here, the fatigue study shows that the three-bladed wind turbine with a teetering hub provides for an approximate sixfold reduction in lifetime blade damage in comparison to a three-bladed turbine with a rigid hub. The second factor is that the addition of a third blade reduces the load on each blade by one-third. Here, the fatigue study shows that a three-bladed turbine with a teetering hub provides for an approximate fourfold reduction in lifetime blade damage in comparison to a two-bladed turbine with a teetering hub.

Copyright © 2015 by ASME
Your Session has timed out. Please sign back in to continue.

References

Ramsland, A., 2014, “Horizontal Axis Wind Turbine With Ball-and-Socket Hub,” U.S. Patent No. 8,708,654.
Ramsland, A., “Horizontal Axis Wind Turbine With Ball-and-Socket Hub,” U.S. patent application U.S. 13/941,542.
Gipe, P., 1995, Wind Energy Comes of Age, Wiley, Hoboken, NJ, p. 297.
Schorbach, V., Dalhoff, P., and Gust, P., 2014, “Taming the Inevitable: Significant Parameters of Teeter End Impacts,” J. Phys. Conf. Ser., 524, p. 012070. [CrossRef]
Jonkman, J., and Buhl, M., 2005, “fast User’s Guide,” National Renewable Energy Laboratory, Golden, CO, Technical Report No. NREL/TP-500-38230.
Jonkman, J., Butterfield, W., Musial, W., and Scott, G., 2009, “Definition of a 5-MW Reference Wind Turbine for Offshore System Development,” National Renewable Energy Laboratory, Golden, CO, Technical Report No. NREL/TP-500-38060.
Jonkman, J., and Musial, W., 2010, “Offshore Code Comparison Collaboration (OC3) for IEA Task 23 Offshore Wind Technology and Deployment,” National Renewable Energy Laboratory, Golden, CO, Report No. NREL/TP-500-48191.
Jonkman, B., and Kilcher, L., 2012, “TurbSim User’s Guide: Version 1.06.00,” National Renewable Energy Laboratory, Golden, CO.
IEC, IEC61400-1, 2005, “ Wind turbines—Part 1,” Design Requirements, 3.0 ed., International Electrotechnical Commission, Geneva, Switzerland.
Hayman, G., 2012, “MLife Theory Manual for Version 1.00,” National Renewable Energy Laboratory, Golden, CO.
Burton, T., Jenkins, N., Sharpe, D., and Bossanyi, E., 2011, Wind Energy Handbook, Wiley, Hoboken, NJ, p. 339.
Epaarachchi, J., and Clausen, P., 2006, “The Development of a Fatigue Loading Spectrum for Small Wind Turbine Blades,” J. Wind Eng. Ind. Aerodyn., 94(4), pp. 207–223. [CrossRef]
Vassilopoulos, A., 2013, “Fatigue Life Prediction of Wind Turbine Blade Composite Materials,” Advances in Wind Turbine Blade Design and Materials, Woodhead Publishing Limited, Cambridge, UK, No. 2, pp. 251–297.
Etemaddar, M., Vahidian, E., and Skjåstad, O., 2014, “Fatigue Damage to the Spar-Type Offshore Floating Wind Turbine Under Blade Pitch Controller Faults,” 33rd International Conference on Ocean, Offshore and Arctic Engineering, Vol. 9A, Ocean Renewable Energy, No. V09AT09A015.
Lee, S., Churchfield, M., Moriarty, P., Jonkman, J., and Michalakes, J., 2013, “A Numerical Study of Atmospheric and Wake Turbulence Impacts on Wind Turbine Fatigue Loadings,” ASME J. Sol. Energy Eng., 135(3), p. 031001. [CrossRef]
Matsuishi, M., and Endo, T., 1968, “Fatigue of Metals Subjected to Varying Stress—Fatigue Lives Under Random Loading,” Jpn. Soc. Mech. Eng., pp. 37–40.
Palmgren, A., 1924, “Die Lebensdauer von Kugellagern,” Z. Deutsch. Ing., 68(1), pp. 339–341.
Miner, M., 1945, “Cumulative Damage in Fatigue,” ASME J. Appl. Mech., 12(3), pp. A159–A164.
Bannantine, J., and Socie, D., 1991, “A Variable Amplitude Multiaxial Fatigue Life Prediction Method,” Fatigue Under Biaxial and Multiaxial Loading, European Structural Integrity Society, ESIS Publication 10, Mechanical Engineering Publications, London, pp. 35–51.
Socie, D., and Marquis, G., 2000, Multiaxial Fatigue, Society of Automotive Engineers, Warrendale, PA, Chap. 4.
Fleming, P., Wright, A., Fingersh, L., and van Wingerden, J., 2011, “Resonant Vibrations Resulting From the Re-Engineering of a Constant-Speed 2-Bladed Turbine to a Variable-Speed 3-Bladed Turbine,” AIAA Paper No. 2011-634. [CrossRef]
Dvorak, P., 2012, “Teetering Toward Two-Blade Turbines,” Windpower Eng. Dev. Available at: http://www.windpowerengineering.com/design/teetering-toward-two-blade-turbines/
Hansen, A., Butterfield, C., and Cui, X, 1990, “Yaw Loads and Motions of a Horizontal Axis Wind Turbine,” ASME J. Sol. Energy Eng., 112(4), pp. 310–314. [CrossRef]
Saranyasoontorn, K., and Manuel, L., 2006, “Symmetry Considerations When Using Proper Orthogonal Decomposition for Predicting Wind Turbine Yaw Loads,” ASME J. Sol. Energy Eng., 128(4), pp. 574–579. [CrossRef]
Yim, S., and Rosen, D., 2012, “Build Time and Cost Models for Additive Manufacturing Process Selection,” Volume 2: 32nd Computers and Information in Engineering Conference, Parts A and B, Chicago, IL, Aug. 12–15.

Figures

Grahic Jump Location
Fig. 1

Wind Turbine undergoing teetering

Grahic Jump Location
Fig. 2

Exploded view of ball-and-socket hub

Grahic Jump Location
Fig. 3

Alternate main shaft ball with fitted transfer assembly

Grahic Jump Location
Fig. 6

Main shaft ball showing teetering arc and teetering plane

Grahic Jump Location
Fig. 7

Wind turbine with ball-and-socket hub protected by nose cone and back protector

Grahic Jump Location
Fig. 8

Teetering and pitch axes of two-bladed wind turbine

Grahic Jump Location
Fig. 9

Teetering and pitch axes of three-bladed wind turbine

Grahic Jump Location
Fig. 10

Lifetime Weibull wind speed distribution

Grahic Jump Location
Fig. 11

Blade 1 teetering profile with three-bladed hub

Grahic Jump Location
Fig. 12

Blade 1 teetering profile with two-bladed hub

Grahic Jump Location
Fig. 13

Rotating bending moment at LSS tip about ya axis with three-bladed hub (LSSTipMya)

Grahic Jump Location
Fig. 14

Rotating bending moment at LSS tip about za axis with three-bladed hub (LSSTipMza)

Grahic Jump Location
Fig. 15

Rotating bending moment at LSS tip about ya axis with two-bladed hub (LSSTipMya)

Grahic Jump Location
Fig. 16

Rotating bending moment at LSS tip about za axis with two-bladed hub (LSSTipMza)

Grahic Jump Location
Fig. 17

Rotating bending moment at low-speed shaft tip about ya axis with three-bladed hub (LSSTipMya) showing spike with teetering hub

Grahic Jump Location
Fig. 18

Nonrotating low-speed shaft bending moment about ys axis at shaft’s strain gage (LSSGagMys)

Grahic Jump Location
Fig. 19

Nonrotating low-speed shaft bending moment about zs axis at the shaft’s strain gage (LSSGagMzs)

Grahic Jump Location
Fig. 20

In-plane bending moment at blade 1 root (RootMxc1)

Grahic Jump Location
Fig. 21

Out-of-plane bending moment at blade 1 root (RootMyc1)

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In