TY - JOUR
T1 - Experimental investigation of the occurrence of transonic flow effects on the FFA-W3-211 airfoil
AU - Aditya, Abhyuday
AU - De Tavernier, Delphine
AU - Schrijer, Ferdinand
AU - Van Oudheusden, Bas
AU - Von Terzi, Dominic
PY - 2024
Y1 - 2024
N2 - For the largest wind turbines currently designed, when operating at rated power and at high wind speeds, the tip airfoils can experience large negative angles of attack. For these conditions and in combination with turbulence, the airfoils are at risk of reaching locally supersonic flow, even at low free-stream Mach numbers. The possibility of shock wave formation and its consequences endangers the lifetime of these largest rotating machines ever built. So far only numerical analyses of this challenge have been attempted with significant modelling uncertainty. Here, for the first time, a wind turbine airfoil (the FFA-W3-211, used at the blade tip of the IEA 15MW reference wind turbine) is studied under transonic conditions using experimental techniques. Schlieren visualization and Particle Image Velocimetry were employed for free-stream Mach numbers of 0.5 and 0.6 and various angles of attack. It was shown that calculations based on isentropic flow theory and compressibility corrections were able to predict the situations where supersonic flow occurred. However, they could not predict the frequency of occurrence and whether shock waves were formed. In conclusion, an unsteady characterization of such airfoil behavior in transonic flow seems to be warranted.
AB - For the largest wind turbines currently designed, when operating at rated power and at high wind speeds, the tip airfoils can experience large negative angles of attack. For these conditions and in combination with turbulence, the airfoils are at risk of reaching locally supersonic flow, even at low free-stream Mach numbers. The possibility of shock wave formation and its consequences endangers the lifetime of these largest rotating machines ever built. So far only numerical analyses of this challenge have been attempted with significant modelling uncertainty. Here, for the first time, a wind turbine airfoil (the FFA-W3-211, used at the blade tip of the IEA 15MW reference wind turbine) is studied under transonic conditions using experimental techniques. Schlieren visualization and Particle Image Velocimetry were employed for free-stream Mach numbers of 0.5 and 0.6 and various angles of attack. It was shown that calculations based on isentropic flow theory and compressibility corrections were able to predict the situations where supersonic flow occurred. However, they could not predict the frequency of occurrence and whether shock waves were formed. In conclusion, an unsteady characterization of such airfoil behavior in transonic flow seems to be warranted.
UR - http://www.scopus.com/inward/record.url?scp=85196397896&partnerID=8YFLogxK
U2 - 10.1088/1742-6596/2767/2/022031
DO - 10.1088/1742-6596/2767/2/022031
M3 - Conference article
AN - SCOPUS:85196397896
SN - 1742-6588
VL - 2767
JO - Journal of Physics: Conference Series
JF - Journal of Physics: Conference Series
IS - 2
M1 - 022031
T2 - 2024 Science of Making Torque from Wind, TORQUE 2024
Y2 - 29 May 2024 through 31 May 2024
ER -