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Influence of Reynolds Number on Multi-Objective Aerodynamic Design of a Wind Turbine Blade.

Ge M, Fang L, Tian D - PLoS ONE (2015)

Bottom Line: To make the study more general, two kinds of multi-objective optimization are involved: one is based on the maximum power coefficient (CPopt) and the ultimate load, and the other is based on the ultimate load and the annual energy production (AEP).It is found that under the same configuration, the optimal design has a larger CPopt or AEP (CPopt//AEP) for the same ultimate load, or a smaller load for the same CPopt//AEP at higher Reynolds number.At a certain tip-speed ratio or ultimate load, the blade operating at higher Reynolds number should have a larger chord length and twist angle for the maximum Cpopt//AEP.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing, P. R. China.

ABSTRACT
At present, the radius of wind turbine rotors ranges from several meters to one hundred meters, or even more, which extends Reynolds number of the airfoil profile from the order of 105 to 107. Taking the blade for 3MW wind turbines as an example, the influence of Reynolds number on the aerodynamic design of a wind turbine blade is studied. To make the study more general, two kinds of multi-objective optimization are involved: one is based on the maximum power coefficient (CPopt) and the ultimate load, and the other is based on the ultimate load and the annual energy production (AEP). It is found that under the same configuration, the optimal design has a larger CPopt or AEP (CPopt//AEP) for the same ultimate load, or a smaller load for the same CPopt//AEP at higher Reynolds number. At a certain tip-speed ratio or ultimate load, the blade operating at higher Reynolds number should have a larger chord length and twist angle for the maximum Cpopt//AEP. If a wind turbine blade is designed by using an airfoil database with a mismatched Reynolds number from the actual one, both the load and Cpopt//AEP will be incorrectly estimated to some extent. In some cases, the assessment error attributed to Reynolds number is quite significant, which may bring unexpected risks to the earnings and safety of a wind power project.

No MeSH data available.


Related in: MedlinePlus

Distributions of (A) twist angle and (B) chord length for design points of A, B, C and D.
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pone.0141848.g008: Distributions of (A) twist angle and (B) chord length for design points of A, B, C and D.

Mentions: Interestingly, although some constraints are implemented artificially in both the chord length and twist angle, the operating α and Cl/Cd show a good agreement with the ideal condition, as shown in Fig 7. It is observed that in multi-objective optimization of the practical blade, distributions of α and Cl/Cd for both A and B are well in agreement with the ideal condition at λopt. As a result, the twist angle of B increases about 1.05 degrees in comparison with that of A, due to that the design α is smaller at higher Reynolds number, as shown in Fig 8A. Similarly, due to the increase of the largest Cl/Cd at higher Reynolds number, CPopt increases accordingly. As shown in Fig 6A, CPopt of A is 0.4918, while CPopt of B is about 0.497.


Influence of Reynolds Number on Multi-Objective Aerodynamic Design of a Wind Turbine Blade.

Ge M, Fang L, Tian D - PLoS ONE (2015)

Distributions of (A) twist angle and (B) chord length for design points of A, B, C and D.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4631510&req=5

pone.0141848.g008: Distributions of (A) twist angle and (B) chord length for design points of A, B, C and D.
Mentions: Interestingly, although some constraints are implemented artificially in both the chord length and twist angle, the operating α and Cl/Cd show a good agreement with the ideal condition, as shown in Fig 7. It is observed that in multi-objective optimization of the practical blade, distributions of α and Cl/Cd for both A and B are well in agreement with the ideal condition at λopt. As a result, the twist angle of B increases about 1.05 degrees in comparison with that of A, due to that the design α is smaller at higher Reynolds number, as shown in Fig 8A. Similarly, due to the increase of the largest Cl/Cd at higher Reynolds number, CPopt increases accordingly. As shown in Fig 6A, CPopt of A is 0.4918, while CPopt of B is about 0.497.

Bottom Line: To make the study more general, two kinds of multi-objective optimization are involved: one is based on the maximum power coefficient (CPopt) and the ultimate load, and the other is based on the ultimate load and the annual energy production (AEP).It is found that under the same configuration, the optimal design has a larger CPopt or AEP (CPopt//AEP) for the same ultimate load, or a smaller load for the same CPopt//AEP at higher Reynolds number.At a certain tip-speed ratio or ultimate load, the blade operating at higher Reynolds number should have a larger chord length and twist angle for the maximum Cpopt//AEP.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing, P. R. China.

ABSTRACT
At present, the radius of wind turbine rotors ranges from several meters to one hundred meters, or even more, which extends Reynolds number of the airfoil profile from the order of 105 to 107. Taking the blade for 3MW wind turbines as an example, the influence of Reynolds number on the aerodynamic design of a wind turbine blade is studied. To make the study more general, two kinds of multi-objective optimization are involved: one is based on the maximum power coefficient (CPopt) and the ultimate load, and the other is based on the ultimate load and the annual energy production (AEP). It is found that under the same configuration, the optimal design has a larger CPopt or AEP (CPopt//AEP) for the same ultimate load, or a smaller load for the same CPopt//AEP at higher Reynolds number. At a certain tip-speed ratio or ultimate load, the blade operating at higher Reynolds number should have a larger chord length and twist angle for the maximum Cpopt//AEP. If a wind turbine blade is designed by using an airfoil database with a mismatched Reynolds number from the actual one, both the load and Cpopt//AEP will be incorrectly estimated to some extent. In some cases, the assessment error attributed to Reynolds number is quite significant, which may bring unexpected risks to the earnings and safety of a wind power project.

No MeSH data available.


Related in: MedlinePlus