analysis of new modeled twisted wind …...this paper highlighted the important of wind energy and...

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International Journal of Mechanical Engineering and Technology (IJMET) Volume 8, Issue 12, December 2017, pp. 1148–1166, Article ID: IJMET_08_12_124 Available online at http://www.iaeme.com/IJMET/issues.asp?JType=IJMET&VType=8&IType=12 ISSN Print: 0976-6340 and ISSN Online: 0976-6359 © IAEME Publication Scopus Indexed

ANALYSIS OF NEW MODELED TWISTED

WIND TURBINE BLADES

S. Selvan Nambi

Research Scholar, Mechanical department, Noorul Islam Centre for Higher Education, Thuckalay, Kanyakumaridist, Tamilnadu, India

G.M. Joselin Herbert

Professor, Mechanical department, Noorul Islam Centre for Higher Education, Thuckalay, Kanyakumaridist, Tamilnadu, India

ABSTRACT

The total wind power installed capacity in India is 27 GW as on 2016-17. Since

energy crises in 1970’s public and private decision makers are considering how to

achieve a sustainable transition from fossil fuel based energy to sustainable and clean

energy namely renewable energy includes wind power, solar power, hydroelectricity,

biomass energy and bio fuels. Renewable energy technologies possess many long term

benefits including energy security job creation sustainable development, business

opportunities and prevention of global warming. Land based utility scale wind is one

of the lowest priced energy source available today. It is a clean fuel source, create

jobs, sustainable energy and eco-friendly. An extensive literature review has been

carried out to review & study the various performance analyses of blades of Wind

Turbine Generators. This paper highlighted the important of wind energy and the

various factors affecting the performance of wind farms. It further presents a case

study on the suitability as performance analysis of a 16.50 MW capacity wind farm

located at Muppandal area, situated in south India. In this paper the LM blade profile

is modified, and analysis were carried out using Ansys software and the results were

discussed. This study will be very much useful to wind turbine blade manufactures and

wind industries to sustainable wind energy generation.

Keywords: Performance, renewable energy, wind energy

Cite this Article: S. Selvan Nambi and G.M. Joselin Herbert, Analysis of New Modeled Twisted Wind Turbine Blades, International Journal of Mechanical Engineering and Technology 8(12), 2017, pp. 1148–1166 http://www.iaeme.com/IJMET/issues.asp?JType=IJMET&VType=8&IType=12

Analysis of New Modeled Twisted Wind Turbine Blades


1. INTRODUCTION

According to the World Bank report 2011, 40% of residences in India had no access to electricity. Wind power has one of the fastest growing important sources of renewable energy and it supports a growing worldwide electricity need. A 4 MW installed capacity wind farm every year could save emission of 300-500 tons of CO2 and 2-3.2 tons of SO2. Hence a brief literature survey has been carried out to study the performance of wind farms, along with a case study on the performance of 16.5 MW wind farm in India. Wind turbine has different technical areas like mechanics, aeronautics, electrical etc. The main components of the wind turbine are blades, hub, main bearing, main shaft; gearbox, brake, high speed shaft, Low sped shaft and generator are shown in Fig.1.

Figure 1 Nomenclature of wind mill [1].

Sarkar and Behera have calculated that 7 % failure will be occurred in the WTBs by considering all other types of failures as shown in Fig.2. For a TSR of 11.6 the maximum efficiency of 30 % is obtained for WTBs. For more practical and accurate design, the environmental factors such as wind direction, corrosion, water vapour intrusion, thermal expansion, mechanical load, summer-winter climate change, ageing and component derating which degrades the performance can be considered [2].

Figure 2 Share of the main components of total number of failures [2].

S. Selvan Nambi and G.M. Joselin Herbert


WTBs have been the most important part of the WT, because more damage will have occurred on the WTB side. The graph as shown in Fig.3 gives the wind rose from the top wind vane data. The compass orientations are based on the true geographic north, rather than the magnetic north. For 22.5º wide sectors wind rose is divided into 16 compass based on the true geographic north [3].

Figure 3 Wind Rose [3]

Table 1 Wind rose [3].

Direction Distribution (V1)

Direction (%)

N 4.6

NNE 7.7

NE 7.5

ENE 4.9

E 3.3

ESE 2.1

SE 2.8

SSE 3.6

S 10.7

SSW 12.7

SW 12.5

WSW 9.0

W 7.1

WNW 3.6

NW 4.4

NNW 3.5

2. WIND ENERGY SCENARIO

From the Fig.4 the worldwide cumulative installed wind power capacity has increased from 24 GW in the year 2001 and has reached 540 GW in the year 2016. From this it is evident that the wind energy installed capacity is gradually going on increasing [4].

Figure 4 Global cumulative installed wind capacity 2001-2016 [4].

24 31 39 4759 74 93

120159

196236

282

318

371

435

486

540

0

100

200

300

400

500

600

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Year

Inst

all

ed

Ca

pa

city

(G

W)



Figure 5 Installed wind power capacity and generation in India since 2005 [5].

The installed wind power capacity and generation in India are plotted in the Fig.5. India’s total installed wind power capacity is 32GW which is 5.9% of global installed capacity. The electricity generation in India for one year from April 2016 to March 2017 is represented as a bar chart in Fig.6. It is clearly in indicate that in the month of July and August produces more than 6,000 GWh [5].

Figure 6 Month wise electricity generation April 2016 – March 2017 [5].

3. PERFORMANCE REVIEW OF NON-TWISTED BLADE

Erich has found that in wind turbine (WT), for design and manufacture of the wind turbine blades (WTBs) 20% total investments have been spent [6]. Tony et al. found that the design of the rotor mostly affects the performance of the WT [7]. Senthil et al. demonstrated numerical simulation using ABA Qus/Explicit finite element code for 12 mm thick M.S plate for ballistics resistance for deficit angles such as 00, 150, 300, 450, 570, 590. The result shows that the resistance of the target has been found to increase with increase in target obliquity [8]. Tang et al. identified that the displacement of wind turbine blade (WTB) sections has been increased from the root to the tip. The maximum displacement of 454 mm in the flap-wise direction for the wind velocity of 60 m/s, whereas the minimum displacement position locates at the blade root, having the characteristics of the cantilever. To avoid collision with the tower

6.277.85

9.58710.925

13.06416.084

18.42120.149

21.26423.354

26.769

32.28

0

5

10

15

20

25

30

35

2004 2006 2008 2010 2012 2014 2016 2018

Year

Inst

all

ed

Ca

pa

city

(G

W)

0

1000

2000

3000

4000

5000

6000

7000

2231.34

4132.07

5854.25

6977.56818.77

5595.97

3607.68

1863.981779.89

2308.452485.97

2355.65

Ele

ctri

city

ge

ne

rati

on

(G

Wh

)

Month



the sufficient tip clearance is provided. The sectional view of various parts such as trailing edge, leading edge, spar cap and shear web of WTB has been shown with pressure distribution is shown in Fig.7 [9].

Figure 7 Display of components and pressure distribution [9]

Table 2 Layup schedule for the blade [9]

Component Radius (%) Z location (mm) Layup schedule Thickness

Root 2.8 to 5 140 to 250 [±45/06/±45/06/+45]s 9.35

Spar cap

5 to 20 250 to 1000 [±45/06/±45/06/+45]s 9.35

20 to 40 1000 to [±45/05/±45/05/+45]s 7.5

40 to 60 2000 to [±45/04/±45/04/+45]s 5.2

60 to 80 3000 to [±45/03/±45/03/+45]s 3.85

80 to 4000 to [±45/02/±45/02/+45]s 2.7

Leading edge 5 to 20 250 to 1000 [±45/02/±45]s 3

20 to 1000 to [±45/0/±45]s 1.85

Trailing edge 5 to 80 250 to 4000 [±45/0/balsa/0/±45]s 7

80 to 4000 to [±45/0]s 1.3

Shear web 5 to 100 250 to 5000 [±45/02/±45]s 3

Table.1 has listed the layup schedule for the wind turbine blade [9]. Scott et al. studied the effect of aeroelastic tailoring on performance characteristics of power generated is theoretically proportional to the square of the WTB length, however the theoretical mass increases cubically [10]. Ju and Sun have stated that WTB vibration will reduce the life of WTB and also will cause tower to vibrate. When rotor speed increases the first vibration natural frequency tend to increase [11]. Lanting has laminate thickness of WTB for root of 80 mm and WTB thickness at tip 20 mm, from root to tip the thickness of WTB sequentially reduces [12]. Almukhtar has studied the effect of drag on the performance of an efficient WTB design. The maximum value of Cp is only 0.47 achieved at a Tip Speed Ratio (TSR) of 7. The torque developed by turbine rises with increasing solidity [13]. Bagherpoor and Xuemin have carried out structural optimization design of 2 MW composite WTB. The introduction of coupling between the structural optimization and the aerodynamic solver with one component working as an objective and the other as a constraint [14]. Mahmuddin analysed WTB performance with Blade Element Momentum (BEM) theory. As the wind speed raises the power also increases for both the developed BEM and θ WTB. There is a slight differences of the results computed by BEM and θ WTB due to the slight difference of lift and drag data exprapolation method in developed BEM and θ WTB software [15]. Hosseini and Imani have Sayed et al. introduce an innovative approach to computer aided design of Horizontal Axis Wind Turbine Blades (HAWTBs). For a cubic B-spline surface for the aerodynamic zone. The strain energy for the averaging method is 2037 where as for the proposed method it is 1788. The reduction in strain energy shows the superiority of proposed



elongation [16]. Gaunaa has studied the unsteady 2D potential flow forces on a thin variable geometry airfoil undergoing arbitrary motion. As in the classic airfoil theory, the airfoil is represented by its camber line and its deflection is given by super position of chord wise deflection mode shapes [17].

4. PERFORMANCE REVIEW OF TWISTED BLADE

Prathiban et al. have analysed the effect of airfoil thickness over pressure distribution in WTBs. Every cross section is twisted to around 40 degrees for optimum performance and higher angle of attack [18]. Sudhamshu et al. have studied the effect of pitch angle on the performance of Horizontal Axis Wind Turbine (HAWT) for the wind velocities of 7, 15.1 and 25.1 m/s by using commercial CFD code fluent. The thrust increases with the increase in wind velocity and decreases with increase in pitch angle. As pitch angle increases normal force on the WTB increases. The maximum value of Chord is obtained at pitch angle of 50 and becomes negative at -100 and 200 [19]. Hassanzadeh et al. optimized and analyzed aerodynamic shape of small WTBs employing the viterna approach for post stall region to maximize its Annual Energy Production (AEP) by BEM theory. It shows an increase of 85 % in the AEP [20]. Cox and Echtermeyer studied geometric sealing effects of bend twist coupling in WTBs. The effect of geometric sealing on bend twist coupling for the WTB length of 30, 50, 70 & 90 m was studied. At the maximum load all WTBs achieved a tip twist between 60 and 70 towards feather. The load reduction of 10-11% is achieved which shows the potential for mass reduction. The load alleviation from bent twist coupling was independent of sealing effects [21]. Thumthae designed a 300 kW twist WTB variable speed HAWT based on BEM. The optimal design of WT reaches 50.5 % efficiency at the design TSR of 7.5 and the same efficiency as maintained for the wind speed range of 4-9 m/s by changing the rotation speeds from 16-36 rpm [22]. Polat and Tuncer have optimized the aerodynamic shape of WTBs using parallel genetic algorithm for Nord tank WT. For the wind speed of 10 m/s there is a 10 % increase in the power production [23]. Tang et al. stated that the WT rotor depends on the wind characteristics of the site and the aerodynamic shape of WTB. Torque and power generated by the rotor is depend on WTB geometry. The chord and twist angle distributions occurs at the 0, 0.5 R hub position and 0.95 R and 1R tip positions, when lift and drag is considered chord reduces gradually from location 0.95 R to 1 R [24]. Simms et al. compared performance of twisted Vs Non twisted HAWTBs. The WTB twist distribution optimizes power production at a single angle of attack along the span for 12 m/s in flow velocity angle of attack ranged from 350 at the 30 % span location to 100 at the 80 % span location. The CL and CD values for NACA 63-418 are shown in Fig.8 and 9 respectively [25].

Figure 8 Derived CL at r = 12.5 m (t/c = 18.20% ) using momentum theory and actuator disk theory. Comparision with 2D wind tunnel measurements [25].



Figure 9 Derived CD at r = 12.5 m (t/c = 18.20% ) using momentum theory and actuator disk theory. Comparision with 2D wind tunnel measurements [25].

Bak et al. compared 2D wind tunnel measurements, from the results it is concluded that CL is low in stall at the tip, good agreement at 0.6 R and high in stall at the inner part of the WTB. CD is in good agreement at the outer part of the WTB, slightly lower at the inner part at the WTB until α = 200, after which it has increased [26]. Stiesdal compared NACA 63 and NACA 44 series WTBs. Better power curve is obtained for low and medium range wind speeds whereas power curve drops under high wind speeds. This profile is more sensitive with surface dirt [27]. The linearly scaled 25 % DU91-W2-250 airfoil followed by 21 % thick NACA 63-4xx series airfoil subjected to wind tunnel tests. To compensate the loss in lift of the upper surface, a certain amount of lower surface behind loading was incorporated, giving typical S-shape of the pressure side in the airfoil DU91-W2-250. In the smooth condition this airfoil gives high peak lift coefficient and gives an acceptable performance in the rough situation. The maximum lift to drag ratio and a smooth stall behavior is the main features of mid span airfoil [28] [29].

5. CASE STUDY OF SREE SASTHA WIND FARM

The parameters are taken from the SREE SASTHA wind farm at Mupandal in Kanya Kumari Dist, TamilNadu. The case study was carried out for three different types of wind mills having LM blade as shown in Fig.10 is presented below:

For 30m height, 13.4 m WTB length for the wind velocity of 13 m/s the maximum power generation is 225 kW/hr and for the wind velocity of 7.6 m/s the maximum power generation reduced to 73 kW/hr for the rotor speed of 37 rpm having the generator speed of 1497 rpm.

The same wind mill with 70 m height produces 2MW for the generator speed of 1600 RPM. For the further increase in speed when it attains 1700 RPM the tip opens and the speed of rpm reduces.

The straight tip shape 530 model having a length of 12 m produces 250 kW.

Figure 10 Actual LM Blade [30]



Oggiano et al. studied the three different aerodynamic profiles (DU91-W2-250, RISØ-A1-21 and NACA 64-418). The DU91-W2-250 airfoil is applied from 20 to 45.6 % span, the RISO-A1-21 airfoil from 54.4 % to 65.6 % span and the NACA 64-418 airfoil outboard of 74.4 % span for the design pitch angle of 2-2.3 deg. The experiment was conducted for both normal operational conditions and fault conditions. For lower freestream velocities or high TSRs large differences between the normal operational and fault conditions can be seen. The large error of 82 % and 92 % indicate that large fluctuations in pressure at the leading edge were measured. Since the fluctuations are limited due to the exclusion of large vibrations [30].

The Table.3 indicates the technical data of LM blade having the length of 13.4 m for a rated power of 200 kW. For this the bolt hole diameter is 700 mm. The ID is assumed as 600 mm [31]. Raciti Castelli et al. have investigated CFD simulation of the flow field using the γ-θ transitional model for the laminar to turbulent transition on the DU91-W2-250 airfoil. The transition from the laminar to turbulent was estimated at 35 % of the chord length [32].

Table 3 Technical data of LM blade [31]

Blade length 13.4 m

Bolt hole circle diameter 700 mm

Rated power 200 kW electric

Rated Rotational Speed 46 RPM

Recommended Max Tip speed 75 m/s

Design wind class IEC 2

Turbulence class A

Maximum chord length 1.29 m

Silhouette area 10.9 m2

Pre – Bend 0.0 m

Blade mass 430 kg

Number of bolts 28

Thread of bolts M16

Production Method Vacuum Infusion

Materials Glass - Fibre Reinforced Plastics

Lightning Protection Aluminum Receptor System

Figure 11 DU 91-W2-250 Airfoil [33] Figure 12 NACA63-418 Airfoil [33]



Figure 13 Lift coefficient curve [33] Figure 14 Drag coefficient curve [33]

Table 4 Criteria for Evaluating Agreements and Discrepancies between Experiments and Computations [33]

Airfoil Name

Average Lift

Difference in

Linear region

Maximum Lift

Location

Difference

Maximum Lift

Difference

Maximum Lift

Difference in stall

NACA 63-418 5.1% 6.6% 16.2% 17.6%

DU 91-W2-250 2.5% 16.7% 7.6% 21.5%

The Table.4 Indicates the criteria for evaluating agreements and discrepancies between experiments and computations.

Table 5 Selected Airfoils Geometrical Parameters [33].

Airfoil Maximum

Thickness

Leading Edge

Maximum curvature

Well- performing airfoils

FX66-S196-V1 19 % 50.0

NACA 63-215 15 % 37.1

NACA 63-415 15 % 41.8

NACA 63-218 18 % 28.8

NACA 63-418 18 % 32.4

FFA-W3-241 24 % 16.5

S814 24 % 21.8

Poorly- performing airfoils

NACA 63-430 30 % 11.2

FFA-W3-211 21 % 24.7

RISO-A1-21 24 % 31.8

NACA 65-421 21 % 27.1

NACA 64-421 21 % 24.1

NACA 63-221 21 % 23.2

The Table.5 presents the geometrical parameters for the selected airfoils [34]. Fuglsang et al. compared LM 21.0 P WTB and the LM 21.0 ASR WTB. The energy yield from both the WTBs are the same. The WTB loads and power load decreased approximately 15 % and 13 % respectively. The power load density distribution slightly decreased [34]



6. BLADE STRUCTURAL MODELING

The modified LM blade structure is designed with the aerofoil having maximum chord length of 1.3 m is with DU- W2-91-250 and minimum chord length of 0.6 m is with NACA 63-418 by removing RISO A1-21 made using CATIA software having a length of 14 m as shown on Fig.15.

Figure 15 Modified LM Blade

Coordinates used in airfoils are tabulated.

Table 6 Coordinates of airfoils (DU-91-W2-250 / NACA64-418)

DU-91-W2-250 NACA 64-418

1300 1 0 600 0 12000

1170 36 0 569 7 12000

1040 67 0 501 22 12000

910 98 0 406 44 12000

780 126 0 295 62 12000

650 148 0 182 65 12000

520 162 0 86 49 12000

390 162 0 20 25 12000

260 143 0 0 2 12000

130 102 0 22 -17 12000

0 2 0 88 -33 12000

117 -111 0 184 -41 12000

260 -153 0 295 -36 12000

390 -163 0 405 -20 12000

520 -153 0 500 -5 12000

650 -127 0 568 1 12000

780 -86 0 600 0 12000

910 -40 0

1040 -4 0

1170 10 0

1300 1 0

The blade structure is generated using CATIA software for without twist and with a twist of (30,60,90,120,150) angles.



7. BLADE STRUCTURAL ANALYSIS

The generated blade structure is analysed for strain, Von mises stress, maximum and minimum principle stress and total deformation and the results were discussed below.

Total Deformation [1-20]

Figure 16 Total deformation

The maximum total deformation 2.131 m is occurs at the tip of the WTB and lees deformation 0.23678 m at longer chord length as shown in Fig.16.

Figure 17 Von-mises stress

The maximum von-mises stress 5.5133e8 N/mm2 is occurs at the maximum chord length flat area and lees stress 1.1279e5 N/mm2 at the tip of the WTB as shown in Fig.17.

Figure 18 Normal stress

The normal max stress -3.0849e7 will affect at the leading edge of the WTB.



Figure 19 Strain energy

The above Fig.19 shows that the max strain energy 60714 Nm occurs at the joint of the WTB with cylinder portion.

Figure 20 Maximum principle stress

The maximum principle stress 2.9312e9 occurs at the flat area and less principle stress (-1.8956e8) will occurs at tip of the WTB as shown in Fig.20.

Figure 20 Maximum principle elastic strain

Minimum principle elastic strain is shown in Fig.21.



8. WITHOUT TWIST WTB

Mode 0, Frequency 1.3891Hz Mode 5, Frequency 15.417 Hz

Mode10, Frequency 50.083Hz Mode 15, Frequency 95.422 Hz

Mode 20, Frequency 150.13 Hz

The above Fig.21 show that the increase of total deformation increases the maximum frequency.

Figure 22 Blade segment Vs Total deformation @ mode 1

For the mode 1 the blades with different twist of represented in graph shows that upto the twist of 120 degrees the deflection increases and afterwards it remains same upto 150 degree.

0

0.02

0.04

0.06

0.08

0.1

0.12

0 2 4 6 8 10

0 deg

30 deg

60 deg

90 deg

120 deg

150 deg

Blade segment

De

form

ati

on




For mode 5 and 10 the same deflection occurs for 0 to 60 degrees and the deflection increases from 60 degree to 120 degree then it remains same.



For the mode 15 the ansys result reveals that the maximum deflection occurs at 90 degree and afterwards it deceases.

0

0.02

0.04

0.06

0.08

0.1

0 2 4 6 8 10

0 deg

30 deg

60 deg

90 deg

120 deg

150 deg

Blade segment

De

form

ati

on

0

0.05

0.1

0.15

0.2

0.25

0.3

0 2 4 6 8 10

0 deg

30 deg

60 deg

90 deg

120 deg

150 deg

Blade segment

De

form

ati

on

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0 2 4 6 8 10

0 deg

30 deg

60 deg

90 deg

120 deg

150 deg

Blade segment

De

form

ati

on



Figure 26 Blade segment Vs Total deformation @ deformation 20

For the mode 20 the least deformation occurs at 90 degree, intermediate deformation occurs for 0 to 90 degree and the maximum deformation occurs at 120 and 150 degrees.

Figure 27 Von mises stress Vs Blade segment

For the various blade segments the Von mises stress is plotted in the Fig.6. From this it is inferred that the least stress occurs at 0 degree and maximum at 120 and 150 degree whereas it is almost same for 30 -90 degrees.

Figure 28 Frequency Vs No of modes

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0 2 4 6 8 10

0 deg

30 deg

60 deg

90 deg

120 deg

150 deg

Blade segment

De

form

ati

on

0.00E+00

5.00E+08

1.00E+09

1.50E+09

2.00E+09

2.50E+09

3.00E+09

3.50E+09

0 2 4 6 8 10

0 deg

30 deg

60 deg

90 deg

120 deg

150 deg

Blade segment

Vo

n m

ise

s st

ress

0

20

40

60

80

100

120

140

160

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

150 deg

120 deg

90 deg

60 deg

30 deg

0 deg

No of modes

Fre

qu

en

cy



The Fig.7 shows the frequency variation for different modes. It is gradually increasing with increasing modes.

Figure 29 Pressure Vs Twisted angle

For the different twisted angle, the pressure variation is shown in Fig.8. From this Fig.8 the average pressure increases upto 30 degree and remain almost same upto 90 degree and rapidly rises upto 120 degrees and its remains same afterwards.

Maximum principle stress

The maximum principle stress occurs at an angle of 90 twist blade and 150 degree twist blade at nearer to the tip and mid of the largest chord respectively.

Minimum principle stress

The minimum principle stress gradually increases from maimum chord length flat area to towards tip.

Strain energy

The strain energy is maximum at maximum chord length for the angle of 30 and 150 degree blades.

9. CONCLUSION

Wind energy is a clean fuel source, create jobs, sustainable energy and eco-friendly. The importance of wind energy and the various factors affecting the performance of wind farms are discussed and case study of a 16.50 MW capacity wind farm located at Muppandal area, situated in south India was carried out. The modified LM blade profile was analyzed and the results were discussed. From this following conclusions were obtained.

• The power generation gradually increased from April to August and gradually decreased afterwards

• From the case study it is concluded that 7% of failure occurs at the wind turbine blades.

0.00E+00

5.00E+08

1.00E+09

1.50E+09

2.00E+09

2.50E+09

3.00E+09

3.50E+09

0 20 40 60 80 100 120 140 160

Minimum Pressure

Average Pressure

Maximum Pressure

Twisted angle (deg)

Pre

ssu

re (

Pa

)



• A linear relationship between load and tip displacement, the deformation of the blade linearly increases with rise in load, which again indicate the blade material is still linear and safe.

• The modified LM blade is safe upto 90 degree because acceptable strain, Von mises stress, maximum and minimum principle stress and total deformation were occurred.

• For 150-degree twist blade all the above mentioned values are beyond the safe value. So it is not advisable to twist 150 degrees for this profile.

From this it is clear that the renewable energy technologies possess long term benefits including energy security job creation sustainable development, business opportunities and prevention of global warming.

REFERENCE

[1] http://researchhubs.com/post/engineering/wind-energy/introduction-to-wind-turbine.html. Date of access 11.12.2017.

[2] A. Sarkar and DK Behera, Wind Turbine Blade Efficiency and Power Calculation with Electrical Analogy, International Journal of Scientific and Research Publications, 2 (2), 2012, 1-5. ISSN 2250-3153. www.ijsrp.org.

[3] Wind Resource Assessment – Met Stat Report - Maple-Hill 1 Site No. 1232 - Generated at 12:45, 07/11/2011. www.hatch.ca.

[4] https://www.statista.com/statistics/268363/installed-wind-power-capacity-worldwide. Date of access 11.12.2017.

[5] https://en.wikipedia.org/wiki/Wind_power_in_India. Date of access 11.12.2017.

[6] H Erich, Wind Turbines: Fundamentals, Technologies, Application, Economics, 2nd edition edn. Springer 2006.

[7] B Tony, S David, J Nick and B Ervin, Wind Energy Handbook. John Wiley & Sons Ltd 2001.

[8] K Senthil, MA Iqbal, P Bhargava and NK Gupta, Experimental and Numerical Studies on Mild Steel Plates against 7.62 API Projectiles, 11th International Symposium on Plasticity and Impact Mechanics, Implast 2016. Procedia Engineering, 173, 2017,369 – 374.

[9] X Tang, R Peng and X Liu. Anthony Ian Broad, Design and Finite Element Analysis of Mixed Aerofoil Wind Turbine Blades, School of Computing, Engineering and Physical Sciences, University of Central Lancashire Fylde Road, Preston, UK 2011.

[10] S Scott, M Capuzzi, D Langston, E Bossanyi, G McCann, PM Weaver and A Pirrera, Effects of aeroelastic tailoring on performance characteristics of wind turbine systems, Renewable Energy, 114, 2017, 887-903.

[11] D Ju and Q Sun, Wind turbine blade flapwise vibration control through input shaping, Proceedings of the 19th World Congress, The International Federation of Automatic Control Cape Town, South Africa, Aug 2014, 24-29.

[12] Z Lanting, Research on Structural Lay-up Optimum Design of Composite Wind Turbine Blade, Energy procedia, 14, 2012, 637-642.

[13] AH Almukhtar, Effect of drag on the performance for an efficient wind turbine blade design, Energy Procedia, 18, 2012, 404–415.

[14] T Bagherpoor and Xuemin, Structural Optimization Design of 2MW Composite wind turbine blade, The 8th International Conference on Applied Energy – ICAE2016, Energy Procedia, 105, 2017, 1226–1233.

[15] F Mahmuddin, Rotor Blade Performance Analysis with Blade Element Momentum Theory, The 8th International Conference on Applied Energy – ICAE2016, Energy Procedia 105, 2017, 1123–1129.



[16] SF Hosseini and BM Imani, Innovative approach to computer-aided design of horizontal axis wind turbine blades, Journal of Computational Design and Engineering 4, 2017, 89–98.

[17] Gaunaa M, Unsteady 2D Potential Flow Forces on a Thin Variable Geometry Aerofoil Undergoing Arbitrary Motion, Riso National Laboratory, Roskilde, Denmark, July 2006.

[18] S Prathiban, M Manickam, P Renuka Devi and TTM Kannan, Effect of aerofoil thickness over pressure distribution in wind turbine blades, International journal of mechanical engineering and robotics research, ISSN 2278 – 0149 www.ijmerr.com. 3 (4), 2014, 564-572.

[19] AR Sudhamshu, MC Pandey, N Sunil, NS Satish, V Mugundhan and RK Velamati, Numerical study of effect of pitch angle on performance characteristics of a HAWT, Engineering Science and Technology, an International Journal, 19, 2016, 632–641.

[20] A Hassanzadeh, AH Hassanabad and A Dadvand, Aerodynamic shape optimization and analysis of small wind turbine blades employing the Viterna approach for post-stall region, Alexandria Engineering Journal, 55, 2016, 2035–2043.

[21] K Cox and A Echtermeyer, Geometric scaling effects of bend-twist coupling in rotor Blades, DeepWind'2013, 24-5 January, Trondheim, Norway. Energy procedia, Jan 2013.

[22] C Thumthae, Optimum Blade Profiles for a Variable-Speed Wind Turbine in Low Wind Area, Energy Procedia, 75, 2015, 651–657.

[23] O Polat and IH Tuncer, Aerodynamic shape optimization of wind turbine blades using a parallel genetic algorithm, Procedia Engineering, 6, 2013, 28-31.

[24] X Tang, X Huang, R Peng and X Liu, A Direct Approach of Design Optimization for Small Horizontal Axis Wind Turbine Blades, Procedia CIRP, 36, 2015, 12–16.

[25] DA Simms, MC Robinson, MM Hand and LJ Fingersh, A Comparison of baseline Aerodynamic Performance of Optimally-Twisted versus Non-Twisted HAWT Blades, National Renewable Energy Laboratory.

[26] C Bak, P Fuglsang, NN Sorensen and H Aagaard Madsen, Chapter 2. Derivation by momentum theory and actuator disk theory, Airfoil Charateristics for wind turbines, Riso National Laboratory, Roskilde, Technical University of Denmark, (March), 1999, 7 -26. ISBN 87-550-2415-7.

[27] H Stiesdal, The aerodynamics of the wind turbine, The wind turbine components and operation, Bonus info 1998, Bonus energy A/S. Fabriksvej 4, Box 170. 7330 BrandeWeb: www.bonus.dk

[28] WA Timmer and R Van Rooij, Summary of the delft university wind turbine dedicated airfoils, AIAA-2003-0352, Journal of Solar energy engineering, Technical papers, 125 (4) 2003, 488-496.

[29] WA Timmer and R Van Rooij, Design of airfoils for wind turbine blades, DUWIND, section Wind Energy, Faculty CiTG, 03 May 2004. https://gcep.stanford.edu/pdfs/energy_workshops_04_04/wind_van_rooij.pdf.

[30] L Oggiano, K Boorsma, G Schepers and M Kloosterman, Comparison of simulations on the NewMexico rotor operating in pitch fault conditions. The Science of Making Torque from Wind (TORQUE 2016). Journal of Physics: Conference Series 753 (2016) 022049. IOP Publishing. doi:10.1088/1742-6596/753/2/022049. Pg [1-10]. IP Address: 192.81.217.249. downloaded on 04/11/2016 at 06:21.

[31] Wind blade 134-0.2.pdf. Date of access 11.12.2017.

[32] M Raciti Castelli, G Grandi and E Benini, Numerical Analysis of Laminar to Turbulent Transition on the DU91-W2-250 airfoil, World Academy of Science, Engineering and Technology, International Journal of Mechanical, Aerospace, Industrial, Mechatronic and Manufacturing Engineering, 6 (3), 2012, 717-724. Scholar.waste.org/publications.



[33] F Bertagnolio, NN Sorensen, J Johansen and P Fuglsang, Wind turbine airfoil catalogue, Denmark 2016; (Oct) 1- 152. ISBN 87 550 2910 8. Forskningscenter Risoe. Risoe-R; No. 1280 (EN).

[34] P Fuglsang, O Sangill and P Hansen, Design of a 21 m Blade with Riso-A1 Airfoils for Active Stall Controlled Wind Turbines, Riso National Laboratory, Roskilde (Dec), 2002, ISBN 87-550-3137-4.

[35] Jose Prasobh M J, D. Karmakar, P K Satheesh Babu, Coupled Dynamic Analysis of a Spar- Type Offshore Floating Wind Turbine, International Journal of Design and Manufacturing Technology (IJDMT), Volume 5, Issue 3, September - December (2014), pp. 41-52

[36] Gayathri.S.Nair, Krishnakumari.T, Comparison of Crowbar Control and Novel Control Methods for Dfig Wind Turbine to Enhance Lvrt Capability under Various Faults, International Journal of Electrical Engineering & Technology (IJEET), Volume 5, Issue 12, December (2014), pp. 14-20

[37] Nadiya G. Mohammed, Application of Crowbar Protection on Dfig-Based Wind Turbine Connected to Grid, International Journal of Electrical Engineering & Technology (IJEET), Volume 4, Issue 2, March – April (2013), pp. 81-92

[38] M. Natesan, Dr. S. Jeyanthi and U. Sivasathya, A Review on Design of Augmented Wind Turbine Blade for Low Wind Speed Urban Area, International Journal of Mechanical Engineering and Technology, 8(7), 2017, pp. 685-692

analysis of new modeled twisted wind …...this paper highlighted the important of wind energy and...

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