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Structural optimization of wind turbine blades with ring shear webs

  • Jie Meng
  • Dagang Sun
Technical Paper

Abstract

The aim of this paper is to present an optimized structure for the design of wind turbine blades. It sets up a forced blade model with ring shear webs and deduces the equations for the inertia moment I y of airfoil section, the maximum stress σmax and the compression ΔD of airfoil relative thickness. Then, the model and the equations are applied to one 750 kw wind turbine. By MATLAB software, the changing trends of the inertia moment I y , the maximum stress σmax, and the compression ΔD, respectively, along with the ratio ε of the inner chord length to the outer and the blade span x are gained. It is concluded that the bending strength around the blade root increases greatly. It also indicates that the bending strength of blades with ring shear webs is almost the same as the blades with solid shear webs when the ratio ε is set as 0.4, and also the use of ring shear webs in wind turbine blade structure leads to lighter blades.

Keywords

Ring shear web Inertia moment Maximum stress Compression Bending strength 

List of symbols

F

Aerodynamic force

Fl

Vertical aerodynamic lift force

Fd

Parallel aerodynamic drag force

α

Attack angle

v

Wind velocity,

c

Airfoil chord length,

G

The gravity of the micro-segment dx

b

Blade span

ρ

Air density

Cd

Drag coefficient

Cl

Lift coefficient

S

Blade area

P

Shear force

M

Bending moment

\(\rho^{\prime}\)

Density of blade material

C

Airfoil perimeter

h

The proportionality coefficient of C and c

λ

Tip-speed ratio

ω

The angular velocity of wind wheel rotation

R

Wind wheel radius

δ

The proportionality coefficient of the blade span to the wind wheel radius

σmax

Maximum normal stress

Iy

The inertia moment of cross section to y-axis

zmax

The distance from the farthest point to the neutral axis

Wy

The module of bending section

εi

Strain

Sij

Flexibility coefficient

u, v, w

Displacements at ring shear webs along the directions x, y and z

η13,3

The first kind of mutual influence coefficient

E

Modulus of elasticity

Gij

Shear modulus

νij

Poisson ratio

ziu(y)

The upper curve of inner ring

zid(y)

The lower curve of inner ring

zou(y)

The upper curve of outer ring

zod(y)

The lower curve of outer ring

am

The power parameter of the polynomial function of the upper curve of outer ring

bm

The power parameter of the polynomial function of the lower curve of outer ring

ε

The ratio of the chord length of the inner ring ci to that of the outer ring co

Ioy

The inertia moment of the outer ring cross section

Iiy

The inertia moment of the inner ring cross section

θ

Rotating angle

ΔD

The airfoil relative thickness compression

Notes

Acknowledgements

The authors wish to express their sincere thanks to Liu Shizhong, Yan Bijuan, Song Yong of Damping Vibration Attenuation Laboratory of Taiyuan University of Science and Technology for their general guidance and technical advice.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

References

  1. 1.
    Han QL, Tian D, Wang HK et al (2007) Test of flow field characteristics of resemble model of concentrated wind energy turbine outside truck-mounted test and analysis. Trans Chin Soc Agric Eng 23(1):110–115.  https://doi.org/10.3321/j.issn:1002-6819.2007.01.020 Google Scholar
  2. 2.
    Bir G, Migliore P (2004) Preliminary structural design of composite blades for two and three-blade rotors. Citeseer, Colorado, pp 1–12CrossRefGoogle Scholar
  3. 3.
    Wang L (2015) Nonlinear aeroelastic modelling of large wind turbine composite blades. Dissertation, University of Central LancashireGoogle Scholar
  4. 4.
    Barnes RH, Morozov EV (2016) Structural optimisation of composite wind turbine blade structures with variations of internal geometry configuration. Compos Struct 152:158–167.  https://doi.org/10.1016/j.compstruct.2016.05.013 CrossRefGoogle Scholar
  5. 5.
    Lin W, Athanasios K, Takafumi N et al (2016) Structural optimisation of vertical-axis wind turbine composite blades based on finite element analysis and genetic algorithm. Compos Struct 153:123–138.  https://doi.org/10.1016/j.compstruct.2016.06.003 CrossRefGoogle Scholar
  6. 6.
    Forcier LC, Simon J (2010) New structural design concepts for large thermoplastic wind turbine blades using structural optimization techniques. Am Inst Aeronaut Astronaut.  https://doi.org/10.2514/6.2010-2578 Google Scholar
  7. 7.
    Wang L, Liu XW, Guo LG et al (2014) A mathematical model for calculating cross-sectional properties of modern wind turbine composite blades. Renew Energy 64:52–60.  https://doi.org/10.1016/j.renene.2013.10.046 CrossRefGoogle Scholar
  8. 8.
    Palacios R, Cesnik CE (2009) Structural models for flight dynamic analysis of very flexible aircraft. Daedalus, Boston, pp 1–17Google Scholar
  9. 9.
    Guo S (2007) Aeroelastic optimization of an aerobatic aircraft wing structure. Aerosp Sci Technol 11:396–404.  https://doi.org/10.1016/j.ast.2007.01.003 CrossRefzbMATHGoogle Scholar
  10. 10.
    Wang L, Liu XW, Renevier N, Stables M, George MH (2014) Nonlinear aeroelastic modelling for wind turbine blades based on blade element momentum theory and geometrically exact beam theory. Energy 76:487–501.  https://doi.org/10.1016/j.energy.2014.08.046 CrossRefGoogle Scholar
  11. 11.
    Hansen MOL (2008) Aerodynamics of wind turbines, 2nd edn. Earthscan, London, pp 7–49Google Scholar
  12. 12.
    Li MF, Zhang KY, Huang L (2007) Mechanics of materials. Science Press, BeijingGoogle Scholar
  13. 13.
    Shen GL, Hu GK (2006) Mechanics of composite materials. Tsinghua University Press, BeijingGoogle Scholar
  14. 14.
    Wu JL (2001) Theory of elasticity. Higher Education Press, BeijingGoogle Scholar
  15. 15.
    Luo ZD, Li JS (1994) Anisotropic material mechanics, 1st edn. Shanghai Jiao Tong University Press, Shanghai, pp 3–22Google Scholar
  16. 16.
    Wang CX, Zhang Y (2003) Wind power generation. China Electric Power Press, BeijingGoogle Scholar

Copyright information

© The Brazilian Society of Mechanical Sciences and Engineering 2018

Authors and Affiliations

  1. 1.Taiyuan University of Science and TechnologyTaiyuanChina

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