DESIGN AND STRUCTURAL ANALYSIS OF POLYMER COMPOSITE

VERTICAL AXIS WIND TURBINE BLADES USING ANSYS

M.SARAVANAN1, K.G.MUTHURAJAN2

1DEPARTMENT OF MECHANICAL ENGINEERING, ASSISTANT PROFESSOR, VINAYAKA

MISSION’S KIRUPANANDA VARIYAR ENGINEERING COLLEGE, VINAYAKA MISSION’S

RESEARCH FOUNDATION( Deemed to be University), SALEM – 636 308, TAMILNADU, INDIA.

E-mail: msaravanan94@gmail.com.

2DEPARTMENT OF MECHANICAL ENGINEERING, SENIOR PROFESSOR, VINAYAKA MISSION’S

KIRUPANANDA VARIYAR ENGINEERING COLLEGE, VINAYAKA MISSION’S RESEARCH

FOUNDATION(Deemed to be University), SALEM – 636 308, TAMILNADU, INDIA.

E-mail: kgmuthurajan@gmail.com.

ABSTRACT This paper studies the potential for installing roof-mounted savonius type Vertical Axis Wind Turbine

(VAWT) systems on house roofs with the goal of maximizing the efficiency and reducing the cost. The

efficiency of the wind turbine depends on the material of the blade, shape of the blade and angle of the blade.

So material of the turbine blade is an important factor in the design of wind turbine. Most of the wind turbine

blades are made of mild steel, stainless steel, aluminum which has more density. This is main cause for huge

weight. It has high corrosion and less fatigue strength. The steel can be replaced by composite material to

reduce the weight, to improve corrosion resistance and fatigue strength, to make them more affordable,

efficient, durable and sustainable. In this paper, Glass Fiber Reinforced Polymer (GFRP) material has been used

to design savonius wind blades of 1 m height and 0.5 m chord length with 4 different arc radius .

For this purpose, modeling software Solid Works is used to model wind blade and static structural analysis of

the GFRP blade was done by using ANSYS.

Key Words : VAWT, Savonius, GFRP, ANSYS.

1. INTRODUCTION

Savonius wind turbine is one of the important type of vertical axis wind turbine used for converting the

force of the wind into torque on a rotating shaft and electric power. The turbine consists of a number of blades

vertically mounted on a rotating shaft. It is less cost and more reliable, but efficiency is poor. This turbine is self

starting and no pointing mechanism is required to allow for shifting wind direction. Sigurd Johannes Savonius

invented this wind turbine in 1922. It was not widely used for many years. Its popularity is increasing recently

due to increase of urbanized areas, which have specific demands. The Savonius rotor blade seems to satisfy

these particular needs.

JASC: Journal of Applied Science and Computations

Volume VI, Issue I, January/2019

ISSN NO: 1076-5131

Page No:236

DESIGN CALCULATION

The power of the wind is proportional to air density, area of the segment of wind being considered, and

the natural wind speed. The relationships between the above variables are provided in equation below.

Pw = ½ ρAV3

where Pw = Power of the wind (W)

ρ = Air density = 1.23 kg/m3

A = Area of a segment of the wind being considered (m2)

= D x H = 1 x 1 = 1 m2

D = Diameter of the turbine in meter

H = Height of the Turbine in meter

V = Wind speed in m/s

The angular velocity of a rotor is given by

ω = λ . V / R

Where λ = Dimensionless factor called the tip speed ratio.

λ is a characteristic of each specific wind mill and for a savonius rotor λ is typically around unity

R = Radius of the rotor

The output of a rotating body is obtained from the product of torque and angular speed.

P = M * ω

P = Output in N-m/s (1 N.m/s = 1W)

M = Torque in N-m

ω = Angular speed / s = 2 π n / 60

n = Rotational speed in rpm = ( 60 ω) / 2π

M = 60 P / 2 π n

According to Betz’s law, the maximum power that is possible to extract from a rotor is

P max = 16/27 * 1/2 *ρ * d * h * v3

The power of wind depends on the swept area of wind turbine and velocity of wind.

JASC: Journal of Applied Science and Computations

Volume VI, Issue I, January/2019

ISSN NO: 1076-5131

Page No:237

Table.1 : Power and Torque of the proposed wind turbine for various wind speeds

SL.

NO

WIND

SPEED

(m/s)

ANGULAR

SPEED

(rad/sec)

ROTATIONAL

SPEED

(RPM)

Pmax

(Watts)

Torque

(N-M)

1 1 2 19 0.36 0.18

2 2 4 38 2.90 0.73

3 3 6 57 9.80 1.63

4 4 8 76 23.22 2.90

5 5 10 96 45.36 4.54

6 6 12 115 78.38 6.53

7 7 14 134 124.46 8.89

8 8 16 153 185.78 11.61

9 9 18 172 264.52 14.70

10 10 20 191 362.85 18.14

11 11 22 210 482.95 21.95

12 12 24 229 627.00 26.13

13 13 26 248 797.18 30.66

14 14 28 267 995.66 35.56

15 15 30 287 1224.62 40.82

Fig.1 : Wind Speed Vs Wind Power

0.00

200.00

400.00

600.00

800.00

1000.00

1200.00

1400.00

POWER(WATTS)

POWER(WATTS)

JASC: Journal of Applied Science and Computations

Volume VI, Issue I, January/2019

ISSN NO: 1076-5131

Page No:238

DESIGN OF SAVONIUS BLADE WITH FOUR DIFFERENT SHAPES

R250 mm R300mm R350 mm Twisted blade

Fig.2 : Different shapes of Wind blades

Dimension : Height : 1000 mm, Rotor Diameter : 1000 mm, Thickness : 3 mm

Each Blade has same chord length of 500 mm with different arc radius.

STATIC STRUCTURAL ANALYSIS OF WIND BLADE

All the four different shapes of GFRP material blades are analyzed with different loads of 500N, 1000N, 1500N

and 2000N. The results are tabulated and the comparisons of the results are plotted.

Fig.3 : Stress, Strain and Total Deformation for R250 mm and R300 mm in 500N loads

Fig.4 : Stress, Strain and Total Deformation for R350 mm and Twisted with R250 mm in 500N loads

Fig.5 : Stress, Strain and Total Deformation for R250 mm and R300 mm in 1000N loads

JASC: Journal of Applied Science and Computations

Volume VI, Issue I, January/2019

ISSN NO: 1076-5131

Page No:239

Fig.6 : Stress, Strain and Total Deformation for R350 mm and Twisted with R250 mm in 1000N loads

Fig.7 : Stress, Strain and Total Deformation for R250 mm and R300 mm in 1500N loads

Fig.8 : Stress, Strain and Total Deformation for R350 mm and Twisted with R250 mm in 1500N loads

Fig.9 : Stress, Strain and Total Deformation for R250 mm and R300 mm in 2000N loads

Fig.10 : Stress, Strain and Total Deformation for R350 mm and Twisted with R250 mm in 2000N loads

JASC: Journal of Applied Science and Computations

Volume VI, Issue I, January/2019

ISSN NO: 1076-5131

Page No:240

RESULT AND DISCUSSION

Table.2 : STRESS (Mpa)

LOAD(N)

GFRP

R250

GFRP

R300

GFRP

R350

GFRP

TWISTED

500 79.441 97.088 285.41 105.51

1000 158.88 194.18 570.82 211.02

1500 238.32 291.26 856.22 316.52

2000 317.77 388.35 1141.6 422.03

Fig.11 : Load Vs Stress

Table.3 : STRAIN

LOAD(N)

GFRP

R250

GFRP

R300

GFRP

R350

GFRP

TWISTED

500 0.010158 0.010584 0.02445 0.0061191

1000 0.020315 0.021168 0.0489 0.012238

1500 0.030473 0.031752 0.073351 0.018357

2000 0.040631 0.042336 0.097801 0.024476

Fig.12 : Load Vs Strain

0

200

400

600

800

1000

1200

GFRP R250 GFRP R300 GFRP R350 GFRP

TWISTED

Series1

Series2

Series3

Series4

0

0.02

0.04

0.06

0.08

0.1

0.12

GFRP R250 GFRP R300 GFRP R350 GFRP TWISTED

Series1

Series2

Series3

Series4

JASC: Journal of Applied Science and Computations

Volume VI, Issue I, January/2019

ISSN NO: 1076-5131

Page No:241

Table.4:Deformation(mm)

LOAD(N) GFRP R250 GFRP R300

GFRP

R350

GFRP

TWISTED

500 593.39 262.16 259.84 433.85

1000 1186.8 524.32 519.67 867.7

1500 1780.2 786.48 779.51 1301.5

2000 2373.6 1048.6 1039.3 1735.4

Fig.13 : Load Vs Deformation

CONCLUSION

The result of static structural analysis to evaluate displacement, stress and strain is good and result

shows that GFRP material can be used to fabricate wind turbine blade with less weight and low cost without

affecting its performance and stability. The maximum stress of 1142MPa and stain of 0.09 is realized in GFRP

R350 blades at 2000N loads. It is suitable for houses in urban areas to produce green energy with available wind

power. The proposed wind turbine can produce electric power of 363 Watts at wind speed of 10 m/s and 1225

Watts at wind speed of 15 m/s which is enough for house use. On comparing with steel, we can reduce the

weight of the material by 1/4th and manufacturing cost by 50%.

REFERENCES

[1] K. A. Brown and R.Brooks, “Design And Analysis Of Vertical Axis Thermoplastic Composite Wind Turbine

Blade”, 2013

[2] Ashwin Dhote, Vaibhav Bankar, “Design, Analysis and Fabrication of Savonius Veritical Axis Wind

Turbine”, IRJET, 2015.

[3] B.Bittumon, Amith Raju, Harish Abraham Mammen, Abhy Thamby, Aby K Abraham, “Design and Analysis

of Maglev Vertical Axis Wind Turbine”, IJETAE, 2014.

[4] MD. Saddam Hussen1 , Dr. K. Rambabu , M. Ramji3 , E. Srinivas4 2Student, Mechanical Engineering,

Sir.C.R.Reddy College of Engineering, Andhra Pradesh, India,” Design and Analysis Of Vertical Axis Wind

Turbine Rotors”, IJRMEE, 2015.

[5] Hikkaduwa Vithanage, Ajith, “Design and Performance Analysis of Pitched-Plate Vertical Axis Wind

Turbine for Domestic Power Generation”, 2012.

0

500

1000

1500

2000

2500

GFRP R250 GFRP R300 GFRP R350 GFRP TWISTED

Series1

Series2

Series3

Series4

JASC: Journal of Applied Science and Computations

Volume VI, Issue I, January/2019

ISSN NO: 1076-5131

Page No:242