Numerical studies of undulation control on dynamic stall for reverse flows

• Published in: Acta mechanica Sinica Vol. 36; no. 2; pp. 290 - 305
• Main Authors: Wang, Biao, Liu, Jian, Yang, Yunjun, Xiao, Zhixiang
• Format: Journal Article
• Language: English
• Published: Beijing The Chinese Society of Theoretical and Applied Mechanics; Institute of Mechanics, Chinese Academy of Sciences 01.04.2020; Springer Nature B.V; China Aerodynamics Research and Development Center,Mianyang 621000,China%China Academy of Aerospace Aerodynamics,Beijing 100074,China; School of Aerospace Engineering,Tsinghua University,Beijing 100084,China%School of Aerospace Engineering,Tsinghua University,Beijing 100084,China
• Edition: English ed.
• Subjects: Aerodynamics; Classical and Continuum Physics; Computational fluid dynamics; Computational Intelligence; Computer simulation; Detached eddy simulation; Engineering; Engineering Fluid Dynamics; Flow separation; Fluid flow; Performance prediction; Research Paper; Shear layers; Theoretical and Applied Mechanics; Three dimensional flow; Flow control; Dynamic stall; Undulating leading edge; Reverse flow; DDES-AC model
• ISSN: 0567-7718; 1614-3116
• DOI: 10.1007/s10409-020-00950-7

The delayed detached-eddy simulation with adaptive coefficient (DDES-AC) method is used to simulate the baseline and leading-edge undulation control of dynamic stall for the reverse flow past a finite-span wing with NACA0012 airfoil. The numerical results of the baseline configuration are compared with available measurements. DDES and DDES-AC perform differently when predicting the primary and secondary dynamic stalls. Overall, DDES-AC performs better owing to the decrease of grey area between the strong shear layer and the fully three-dimensional separated flow. Moreover, the effects of the undulating leading-edge on the forces, lift gradients, and instantaneous flow structures are explored. Compared with the uncontrolled case, the lift gradient in the primary dynamic stall is reduced from 18.4 to 8.5, and the secondary dynamic stall disappears. Therefore, periodic unsteady air-loads are also reduced. Additionally, the control mechanism of the wavy leading edge (WLE) is also investigated by comparison with the straight leading edge (SLE). No sudden breakdown of strong vortices is the main cause for WLE control.