TY - JOUR
T1 - Study of air compressibility effects on the aerodynamic performance of the IEA-15 MW offshore wind turbine
AU - Cao, Jiufa
AU - Qin, Zhaojie
AU - Chen, Yuanhang
AU - Shen, Wen Zhong
AU - Shen, Xiang
AU - Ke, Shitang
N1 - Funding information: This work was funded by the National Natural Science Foundation of China under grant number (51906210).
PY - 2023/4/15
Y1 - 2023/4/15
N2 - With the gradual upscaling of offshore wind turbines, the blade size becomes large and the blade tip velocity reaches almost a Mach number of 0.3, the limit of the incompressible flow assumption. To simulate wind turbine flows, an incompressible solver was often a good choice as it gave good predictions and the Mach number of the wind turbine flows were small. When the Mach number is increased to be close to 0.3, the validity of incompressible flow may be questionable and thus needs to be checked. In this paper, an accurate wind turbine flow solution method is proposed to study the compressibility effects. First, the National Renewable Energy Laboratory (NREL) Phase VI wind turbine is used as an example to verify the method at a small Mach number. Through a comparative analysis between the compressible, the incompressible numerical results, and experimental data, the proposed method is found with a good simulation accuracy. Next, the flow fields of the large wind turbine IEA-15 MW, under different wind conditions are simulated. The local Mach number, density and pressure coefficient at different blade cross-sections of the compressible results are analyzed and compared to its incompressible ones, and the influences of compressibility on the thrust, torque and power of the wind turbine are quantified. The results show that at the rated wind speed, the thrust of the compressible flow simulation is 1.40 % higher than that of the incompressible one, and the torque of the compressible flow simulation is nearly 11.07 % higher than that of the incompressible one. As a result, the compressibility effects are recommended to be added in future studies of large wind turbines.
AB - With the gradual upscaling of offshore wind turbines, the blade size becomes large and the blade tip velocity reaches almost a Mach number of 0.3, the limit of the incompressible flow assumption. To simulate wind turbine flows, an incompressible solver was often a good choice as it gave good predictions and the Mach number of the wind turbine flows were small. When the Mach number is increased to be close to 0.3, the validity of incompressible flow may be questionable and thus needs to be checked. In this paper, an accurate wind turbine flow solution method is proposed to study the compressibility effects. First, the National Renewable Energy Laboratory (NREL) Phase VI wind turbine is used as an example to verify the method at a small Mach number. Through a comparative analysis between the compressible, the incompressible numerical results, and experimental data, the proposed method is found with a good simulation accuracy. Next, the flow fields of the large wind turbine IEA-15 MW, under different wind conditions are simulated. The local Mach number, density and pressure coefficient at different blade cross-sections of the compressible results are analyzed and compared to its incompressible ones, and the influences of compressibility on the thrust, torque and power of the wind turbine are quantified. The results show that at the rated wind speed, the thrust of the compressible flow simulation is 1.40 % higher than that of the incompressible one, and the torque of the compressible flow simulation is nearly 11.07 % higher than that of the incompressible one. As a result, the compressibility effects are recommended to be added in future studies of large wind turbines.
KW - Offshore wind turbine
KW - Air compressibility
KW - Computational fluid dynamics
KW - Aerodynamic performance
UR - http://www.scopus.com/inward/record.url?scp=85149646775&partnerID=8YFLogxK
U2 - 10.1016/j.enconman.2023.116883
DO - 10.1016/j.enconman.2023.116883
M3 - Article
SN - 0196-8904
VL - 282
JO - Energy Conversion and Management
JF - Energy Conversion and Management
M1 - 116883
ER -