TY - GEN
T1 - Design Optimization of Airfoils at Ultra-Low Reynolds Numbers
AU - Xu, Jianhua
AU - Li, Dan
AU - Song, Wenping
AU - Han, Zhonghua
AU - Li, Huijing
N1 - Publisher Copyright:
© 2021 32nd Congress of the International Council of the Aeronautical Sciences, ICAS 2021. All rights reserved.
PY - 2021
Y1 - 2021
N2 - Spoon shaped airfoil has high lift-to-drag ratio at ultra-low Reynolds numbers (ranges from 10,000 to 100,000), but instable separated flow on lower surface near trailing edge result to obvious unsteady effect, which affects the controllability and stability of the aircraft. This paper aims to design airfoils not only to improve the time-averaged lift-to-drag ratio, but also to weaken the unsteady effect. An efficient optimizer based on Kriging surrogate model, named “SurroOpt” is used for airfoil design. An in-house URANS (unsteady Reynolds-averaged Navier-Stokes) solver with SST transition model for flow transition is utilized to simulate the flows around airfoils. Both single-point and two-point design are investigated. The results demonstrate that the time-averaged lift-to-drag ratio of the optimized airfoil is higher than that of baseline in a wide range of angles of attack. Meanwhile, the unsteady amplitudes of aerodynamic force are reduced. It is concluded that the developed unsteady aerodynamic design method achieves the design goal of improving lift-to-drag ratio and reducing unsteady effect.
AB - Spoon shaped airfoil has high lift-to-drag ratio at ultra-low Reynolds numbers (ranges from 10,000 to 100,000), but instable separated flow on lower surface near trailing edge result to obvious unsteady effect, which affects the controllability and stability of the aircraft. This paper aims to design airfoils not only to improve the time-averaged lift-to-drag ratio, but also to weaken the unsteady effect. An efficient optimizer based on Kriging surrogate model, named “SurroOpt” is used for airfoil design. An in-house URANS (unsteady Reynolds-averaged Navier-Stokes) solver with SST transition model for flow transition is utilized to simulate the flows around airfoils. Both single-point and two-point design are investigated. The results demonstrate that the time-averaged lift-to-drag ratio of the optimized airfoil is higher than that of baseline in a wide range of angles of attack. Meanwhile, the unsteady amplitudes of aerodynamic force are reduced. It is concluded that the developed unsteady aerodynamic design method achieves the design goal of improving lift-to-drag ratio and reducing unsteady effect.
KW - Laminar separation bubble
KW - Ultra-low reynolds numbers
KW - Unsteady aerodynamic design of airfoil
UR - http://www.scopus.com/inward/record.url?scp=85122077695&partnerID=8YFLogxK
M3 - 会议稿件
AN - SCOPUS:85122077695
T3 - 32nd Congress of the International Council of the Aeronautical Sciences, ICAS 2021
BT - 32nd Congress of the International Council of the Aeronautical Sciences, ICAS 2021
PB - International Council of the Aeronautical Sciences
T2 - 32nd Congress of the International Council of the Aeronautical Sciences, ICAS 2021
Y2 - 6 September 2021 through 10 September 2021
ER -