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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

Pareto frontiers based on Mxy-r and AEP in planes of (A) Cpopt-AEP, (B) Cpopt-λopt.
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pone.0141848.g013: Pareto frontiers based on Mxy-r and AEP in planes of (A) Cpopt-AEP, (B) Cpopt-λopt.

Mentions: Fig 12C and 12D shows the AEP and load of Pareto frontiers against λopt. In general, both the AEP and load decrease with λopt, quite similar to the first kind optimization. But the design points with λopt<10.9 in this optimization, which have a larger AEP and load, are missed in the first kind optimization, which is shown if Fig 6B. Furthermore, Pareto frontiers based on Mxy-r and AEP are plotted in both the planes of Cpopt-AEP and Cpopt-λopt in Fig 13. As can be seen, in optimization, AEP and Cpopt do not have a positive correlation in a strict sense. Conversely, at a high value of AEP, Cpopt decreases with AEP. Hence, in the optimization based on CPopt and Mxy-r, designs with lower CPopt and λ but larger AEP and load are missed. Therefore, in aerodynamic design of a wind turbine blade, special attention should be paid to λopt which is slightly lower than the very λopt, to achieve the maximum CPopt, because in this region, blades usually have a larger AEP but smaller CPopt.


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

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

Pareto frontiers based on Mxy-r and AEP in planes of (A) Cpopt-AEP, (B) Cpopt-λopt.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0141848.g013: Pareto frontiers based on Mxy-r and AEP in planes of (A) Cpopt-AEP, (B) Cpopt-λopt.
Mentions: Fig 12C and 12D shows the AEP and load of Pareto frontiers against λopt. In general, both the AEP and load decrease with λopt, quite similar to the first kind optimization. But the design points with λopt<10.9 in this optimization, which have a larger AEP and load, are missed in the first kind optimization, which is shown if Fig 6B. Furthermore, Pareto frontiers based on Mxy-r and AEP are plotted in both the planes of Cpopt-AEP and Cpopt-λopt in Fig 13. As can be seen, in optimization, AEP and Cpopt do not have a positive correlation in a strict sense. Conversely, at a high value of AEP, Cpopt decreases with AEP. Hence, in the optimization based on CPopt and Mxy-r, designs with lower CPopt and λ but larger AEP and load are missed. Therefore, in aerodynamic design of a wind turbine blade, special attention should be paid to λopt which is slightly lower than the very λopt, to achieve the maximum CPopt, because in this region, blades usually have a larger AEP but smaller CPopt.

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