The document presents the theoretical and computational investigation of an optimized horizontal-axis wind turbine blade for power extraction at wind farms in Bangladesh. The researchers designed and modeled a blade using the SD7080 airfoil profile. Computational fluid dynamics simulations validated the blade element momentum theory used in the design. The optimized blade was found to have higher annual power output and lower unit cost of energy than a commercial Enercon turbine, while requiring more land area for a wind farm.

1. Theoretical and Computational Investigations of Optimized
Blade of Horizontal-axis Wind Turbine for Power Extraction at Wind Farm.
Presented By:
Suraj Prasad Subedi Prosunto Kumar Biswas
Student ID:1707401 Student ID:1707421
Shuvashis Biswas Muradul Kabir
Student ID: 1707411 Student ID:1707436
Under the Supervision of
Sudipta Paul
Lecturer
Department of Mechanical Engineering
Hajee Mohammad Danesh Science and Technology University

2. Introduction
Technology Off-grid
(MWp)
On-grid
(MWp)
Technology Off-grid
(MWp)
On-grid
(MWp)
Total
(MWp)
Solar 349.57 203.36 Solar 349.57 203.36 552.93
Wind 2 0.9 Wind 2 0.9 2.9
Hydro 0 230 Hydro 0 230 230
Biogas to
Electricity
0.69 0 Biogas to
Electricity
0.69 0 0.69
Biomass to
Electricity
0.4 0 Biomass to
Electricity
0.4 0 0.4
Total 352.66 434.26 Total 352.66 434.26 786.92
Renewable Energy Share at Bangladesh Renewable Energy Installed Capacity
Despite wind energy being the fastest-growing clean energy source due to its zero-emission nature, Bangladesh is
lagging behind in transition from non-renewable energy to wind energy.
"Sustainable and renewable energy development authority(SREDA),"

3. Research
Outline

11. Research
Outline

12. Site Selection
Monthly mean wind speed in three sites at 10m height (2020)
0
1
2
3
4
5
6
7
JAN FB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG
Sayedpur Hatiya Kutubdia
The Bay of Bengal and the Ganges of Brahmaputra Meghna, which pass through 19 of Bangladesh's 64 districts, dominate the country's
coastal zone geomorphologically (sarwar & islam). It covers 47,201 km2 which is almost 32% of whole country (Islam, Xue, & Rahman,
2009). Among them we primarily select three sites from two divisions. where Hatia, Kutubdia situated in Chittagong division and Sayedpur
situated in Rangpur division. To produce wind energy, speed of wind is most important.
SK. S. Islam, X.-Z. Xue and M. M. Rahman, Journal of Wetlands Ecology, vol. 2, pp. 35-41, 2009.

13. Site Selection
wind speed at various altitude
map of chittagong division
Adjacent to Bay of Bengal
Area 2100 km2
Division, District Chittagong, Noakhali
Latitudes (22.07° - 22.35°) north
Longitudes (90.56° - 91.11°) east
Geographical Location of Hatiya Island
https://en.wikipedia.org/wiki/Hatiya_Island.

14. Hatiya Island
 Inhabited to about 452,463 people.
 Island is not connected to the national electrical system. (local grid)
 Three diesel generators with a total capacity of 400 kVA.
 Production of a combined 500 kW.

15. Extrapolation of wind data at Hatiya
Criteria Jan Feb March April May June July Aug Sep Oct Nov Dec Avg.
Wind speed 3.75 4.02 5.41 7.39 7.25 8.21 8.01 6.81 5.16 3.37 2.76 2.79 5.41
Scale Para. 4.48 4.81 6.41 8.68 8.51 9.62 9.38 8.02 6.12 4.05 3.33 3.36 6.40
0
1
2
3
4
5
6
7
8
9
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
10m 30m 50m 60m
Monthly mean wind speed variation at different height
0
2
4
6
8
10
12
Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec
10m 30m 50m 60m
Monthly scale parameter at different height

16. HAWT Blade Design
𝑇𝑆𝑅 =
𝑠𝑝𝑒𝑒𝑑 𝑜𝑓 𝑟𝑜𝑡𝑜𝑟 𝑡𝑖𝑝
𝑤𝑖𝑛𝑑 𝑠𝑝𝑒𝑒𝑑
power coefficient
Cp (= P/Pwind)
Cp max = 16/27 = 0.593
animation.http://www.chrvojeengineering.com

17. Selection of Airfoil
SG 6043 NACA 65-415
SD 7080
NACA 4418
Airfoils suitable for low Reynolds number application
were selected from airfoil database .
Reynolds Number=82000

18. Determination of Chord Length & Twist Angle
r/R = Cr
Cross
Section
No.
Local
radius
of
rotor,
r
Local
design
speed,
Relative wind speed
angle
𝛟 =
𝟐
𝟑
𝐚𝐫𝐜 𝐭𝐚𝐧(
𝟏
𝛌𝐫
)
Angle
of
Attack,
Twist
angle
Chord,
Cr
m Degree Degree Degree m
1 1 0.43 44.53 5.5 39.034 2.734
2 3 0.8 25.25 5.5 19.750 2.729
3 5 1.2 16.68 5.5 11.178 2.002
4 7 1.6 12.29 5.5 6.79 1.527
5 9 2.0 9.69 5.5 4.190 1.222
6 11 2.4 7.98 5.5 2.484 1.015
7 13 2.8 6.78 5.5 1.284 0.866
Schmitz formula
Blade Radius
R=
2𝑃𝑒
𝜌𝜋𝑉𝛼
3
𝐶𝑝
C(r)=
16πr
B(CL)D
sin2
(
1
3
arctan(
R
rλD
))
β(r) =
2
3
arctan
R
r
1
λD
– αD
r/R = β

19. Calculation of Power Coefficient ( BEMT Method )
flow chart of matlab code generation blade generated in q-blade software

20. Simulation Methodology

21. Meshed flow domain
Closer view of mesh generated around
the airfoil

22. Pressure and Velocity Contour
Pressure co-efficient on SD7080 airfoil
velocity contour on blade from CFD
pressure contour on blade from CFD

23. Blade Placement in Flow Domain
Blade Geometry made in SolidWorks-2019
View of blade placement from rotor axis
Blade placement in fluid domain
For computational flow’s
inlet & outlet diameter=3R
For Rotor
domain is expanded to 3R for front-stream direction
domain is expanded to 6R for back-stream direction

24. Boundary Condition for Mesh
Generated Volume Mesh of fluid domain
Generated Face Mesh of fluid domain
Boundary Condition Choice
Simulation type Steady simulation
Fluid material Air
Flow type Incompressible flow
Temperature 300 K
Kinematic viscosity 1.7894e-05 m2/s
Pressure 101,325 Pa
Wind speed 5.4 m/s
CFD algorithm SIMPLE
Viscous model SST k–omega
Solution methods Pressure–velocity coupling
Least-squares cell based
Pressure(standard);density
(second-order upwind) Momentum
(second-order upwind) Turbulent kinetic energy
(first-order upwind) Specific dissipation rate
(first-order upwind)
Solution controls Pressure: 0.5
Momentum: 0.5
Density: 1.225 kg/m3
Turbulent kinetic energy: 0.75
Boundary
Conditions Velocity inlet (5.4 m/s); Velocity inlet top
(5.4m/s)
pressure outlet (gauge
pressure: 0)
Moving wall with no-slip shear condition
Cell Zone Condition Frame Motion
Rotational Velocity 6.3 rad/s
Number of mesh cells About 1270000

25. Scaled Residual for Flow Domain
Scaled residuals of calculation
Complete flow domain around the blades

26. Results and Discussion

27. Analysis of SD 7080 blade at different Reynolds Number
Reynolds Number (𝐶𝑙)𝑚𝑎𝑥 (𝐶𝑙/𝐶𝑑) 𝑚𝑎𝑥
30000 0.81 12.5
60000 1.15 39.7
82000 1.17 46.47
10000 1.18 53.4
125000 1.20 59.8
Cp values initially increase with the
increase in the value of tip speed ratio (λ),
reaches the maximum, and then decreases.
Cp reaches maximum at λ=5.5 0.42
Cp at 𝜆𝑑𝑒𝑠𝑖𝑔𝑛 =6 0.412

28. Velocity Streamline & Power through CFD
Through Function Calculator present in the result section of CFD,
Torque in the blade wall was found ( T ) = 3665.6 [N m] (one blade )
applying equation,
Average Power = 69.094 kW
The values of the power coefficient of SD7080 obtained by CFD is smaller than the
values of the power coefficient obtained by BEM.

29. Comparison of Cp & Power Output with Commercial Turbine
0.412
0.3962
0.3878
0.4
0.375
0.38
0.385
0.39
0.395
0.4
0.405
0.41
0.415
Q-Blade BEM CFD Enercon E-30
Cp
Turbine
Though Enercon E-30 while working at full efficiency have similar power
coefficient as the power coefficient of designed blade but has less annual power
generation than the designed blade.
Capacity factor, Cf 19.74%
Average power output,𝑃
𝑎𝑣𝑔 59.22 KW
Annual energy power output
(𝐸𝑜𝑢𝑡)
174.3 MWh
Capacity factor, Cf 30%
Average power output,𝑃
𝑎𝑣𝑔 70.68 KW
Annual energy power output
(𝐸𝑜𝑢𝑡)
198.5 MWh
Terms Values
Cut-in speed, Vc 2.5 (𝑚𝑠−1
)
Cut-off speed, Vf 13.5 (𝑚𝑠−1
)
Rated speed, Vr 25 (𝑚𝑠−1
)
Scale factor, c 6.39
Shape parameter, k 2
SD7080 BEMT blade
Enercon E-30

30. Calculation of PVC and Unit Cost
Serial Terms SD7080 Enercon E-30
1. Investment, I 317400 USD 414000 USD
2. Pay back period, n 10 years 10 years
3. Lifetime,T 20 years 20 Years
4. Comr 3306.3 USD 4312.5USD
5. Inflation rate,i 0.12 0.12
6. Interest rate,r 0.15 0.15
7. Scrap value,s 31740 USD 41400 USD
8. PVC 101389.6 USD 132246.7 USD
9. Eout 198.5 MWh 174.3 MWh
10. Unit cost($/KWh) 0.051 USD 0.076 USD
PVC=I +𝐶𝑜𝑚𝑟
1+𝑖
𝑟−𝑖
∗ 1 −
1+𝑖
1+𝑟
𝑛
− 𝑠
1+𝑖
1+𝑟
𝑛
A. Mohamed and B. Jamel, Environmental Science

31. Calculation of Required land area for two turbines
Serial Terms SD7080 Enercon E-30
1. Wind speed 5.41 ms-1 5.41 ms-1
2. Power density 96.984 Watt/m2
96.984 Watt/m2
3. Power available per square meter 2.63 Kwh/year/m2
2.63 Kwh/year/m2
4. Annual power output 198.5MWh 174.3MWh
5. Land area 75475.29 m2 66282.89 m2
Pavg m2=
Pdensity
320
Land area=
𝐸𝑜𝑢𝑡
𝑝𝑎𝑣𝑔 𝑚2
A. Mohamed and B. Jamel, Environmental Science

32. Conclusion
In the present study, designing and modeling of horizontal turbine blade was analyzed and studied.
Key Outcomes:
 SD7080 showed very good performance of lift to drag ratio and lift coefficient, thus selected due to its soft stall behavior
at different angle of attack.
 Blade was designed in q-blade(version-2) software by blade element momentum theory (BEMT).
 CFD results validated the BEM theorem in terms of power coefficient.
 Cp calculated from BEMT = 0.3962 and that obtained by CFD = 0.3878.
 Annual Power Output of SD 7080 BEMT blade = 198.5 MWh while of Enercon E-30 = 174.324 MWh.
 Unit cost($/kwh) seemed to be 0.051 USD for SD7080 while 0.076 USD for Enercon E-30.
 But Land requirement for the wind farm resulted to be lesser for Enercon E-30 than optimized SD7080 BEMT blade. i.e.
75475.29 m2 for SD7080 & 66282.89 m2 for Enercon E-30.

33. Thank You