The Shock wave Control Bump (SCB) can effectively weaken the shock wave intensity of the airfoil at transonic speeds, meanwhile exerting a positive effect on transonic buffet control. In this study, the URANS method is applied to numerical simulation to explore the control effect of the 2D SCB on the OAT15A supercritical airfoil under the transonic buffet condition. The differences between the two goals of drag reduction and buffet control are further investigated. Two bumps are designed with drag reduction optimization at cruise design points. Under the buffet condition, the bumps delayed the pressure recovery on the upper surface of the airfoil and weakened the interaction between the shock wave and the boundary layer. Therefore, the pressure fluctuation amplitude of bump configurations is reduced despite incomplete suppression of the buffet. Then, the effect of the bump crest position, height and length on the buffet is studied. The working mechanism of the SCB to suppress the buffet is obtained by analyzing the typical flow field. The bump reduced the shock wave intensity, preventing the boundary layer at the rear of the bump from moving upstream and interfering with the shock wave, resulting in shock buffet suppression. Based on the drag reduction design at the cruise design point, the relative reference positions of the two bumps are 0.04c and 0.10c (c representing length of the chord), respectively. The position range of the bumps at the same height to completely suppress the buffet without reducing the lift are[-0.01, 0.02]c and[0.01, 0.08]c, respectively. The smallest variation of the bump location between drag reduction and shock buffet control is 0.02c, and this distance has a significant impact on cruise characteristics and buffet performance of the airfoil. Consequently, the two types of bumps designed based on drag reduction at the cruise points and buffet control under the buffet condition have different crest positions. In engineering design, a trade-off between the two design goals should be achieved in bump design by comprehensive consideration to improve the overall performance of airfoils under transonic flight conditions.
[1] 李沛峰, 张彬乾, 陈迎春, 等. 减小翼型激波阻力的鼓包流动控制技术[J]. 航空学报, 2011, 32(6):971-977. LI P F, ZHANG B Q, CHEN Y C, et al. Wave drag reduction of airfoil with shock control bump[J]. Acta Aeronautica et Astronautica Sinica, 2011, 32(6):971-977(in Chinese).
[2] 张伟伟, 高传强, 叶正寅. 机翼跨声速抖振研究进展[J]. 航空学报, 2015, 36(4):1056-1075. ZHANG W W, GAO C Q, YE Z Y. Research advances of wing/airfoil transonic buffet[J]. Acta Aeronautica et Astronautica Sinica, 2015, 36(4):1056-1075(in Chinese).
[3] 田云, 刘沛清, 彭健. 激波控制鼓包提高翼型跨声速抖振边界[J]. 航空学报, 2011, 32(8):1421-1428. TIAN Y, LIU P Q, PENG J. Using shock control bump to improve transonic buffet boundary of airfoil[J]. Acta Aeronautica et Astronautica Sinica, 2011, 32(8):1421-1428(in Chinese).
[4] LEE B H K. Self-sustained shock oscillations on airfoils at transonic speeds[J]. Progress in Aerospace Sciences, 2001, 37(2):147-196.
[5] XIAO Q, TSAI H M, LIU F. Numerical study of transonic buffet on a supercritical airfoil[J]. AIAA Journal, 2006, 44(3):620-628.
[6] DECK S. Zonal-detached-eddy simulation of the flow around a high-lift configuration[J]. AIAA Journal, 2005, 43(11):2372-2384.
[7] DECK S. Numerical simulation of transonic buffet over a supercritical airfoil[J]. AIAA Journal, 2005, 43(7):1556-1566.
[8] IOVNOVICH M, RAVEH D E. Reynolds-averaged navier-stokes study of the shock-buffet instability mechanism[J]. AIAA Journal, 2012, 50(4):880-890.
[9] GONCALVES E, HOUDEVILLE R. Turbulence model and numerical scheme assessment for buffet computations[J]. International Journal for Numerical Methods in Fluids, 2004, 46(11):1127-1152.
[10] CARUANA D, MIGNOSI A, ROBITAILLIÉ C. Separated flow and buffeting control[J]. Flow, Turbulence and Combustion (formerly Applied Scientific Research), 2003, 71(1-4):221-245.
[11] CARUANA D, MIGNOSI A, CORRōGE M, et al. Buffet and buffeting control in transonic flow[J]. Aerospace Science and Technology, 2005, 9(7):605-616.
[12] IOVNOVICH M, RAVEH D E. Transonic unsteady aerodynamics in the vicinity of shock-buffet instability[J]. Journal of Fluids and Structures, 2012, 29:131-142.
[13] 高传强, 张伟伟, 叶正寅. 基于谐振舵面的跨声速抖振抑制探究[J]. 航空学报, 2015, 36(10):3208-3217. GAO C Q, ZHANG W W, YE Z Y. Study on transonic buffet suppression with flapping rudder[J]. Acta Aeronautica et Astronautica Sinica, 2015, 36(10):3208-3217(in Chinese).
[14] GAO C Q, ZHANG W W, YE Z Y. Numerical study on closed-loop control of transonic buffet suppression by trailing edge flap[J]. Computers & Fluids, 2016, 132:32-45.
[15] GAO C, ZHANG W, KOU J. Active control of transonic buffet flow[J]. Journal of Fluid Mechanics, 2017,824:312-351.
[16] ASHILL P R, LOCK W W. A novel technique for controlling shock strength of laminar flow aerofoil sections[C]//Proceedings 1 st European Forum on Laminar Flow Technology, 1992.
[17] QIN N, WONG W S, LE MOIGNE A. Three-dimensional contour bumps for transonic wing drag reduction[J]. Proceedings of the Institution of Mechanical Engineers, Part G:Journal of Aerospace Engineering, 2008,222,5:619-629.
[18] BIRKEMEYER J, ROSEMANN H, STANEWSKY E. Shock control on a swept wing[J]. Aerospace Science and Technology, 2000, 4(3):147-156.
[19] MAYER R, LUTZ T, KRÄMER E. Numerical study on the ability of shock control bumps for buffet control[J]. AIAA Journal, 2018, 56(5):1978-1987.
[20] TIAN Y, GAO S Q, LIU P Q, et al. Transonic buffet control research with two types of shock control bump based on RAE2822 airfoil[J]. Chinese Journal of Aeronautics, 2017, 30(5):1681-1696.
[21] GEOGHEGAN J A, GIANNELIS N F, VIO G A. Parametric study of active shock control bumps for transonic shock buffet alleviation[C]//AIAA Scitech 2020 Forum. Reston:AIAA, 2020.
[22] GEOGHEGAN J, GIANNELIS N, VIO G. A numerical investigation of the geometric parametrisation of shock control bumps for transonic shock oscillation control[J]. Fluids, 2020, 5(2):46.
[23] 肖志祥, 罗堃宇, 刘健. 宽速域RANS-LES混合方法的发展及应用[J]. 空气动力学学报, 2017, 35(3):338-353. XIAO Z X, LUO K Y, LIU J. Developments and applications of hybrid RANS-LES methods for wide-speed-range flows[J]. Acta Aerodynamica Sinica, 2017, 35(3):338-353(in Chinese).
[24] GIANNELIS N F, LEVINSKI O, VIO G A. Influence of Mach number and angle of attack on the two-dimensional transonic buffet phenomenon[J]. Aerospace Science and Technology, 2018, 78:89-101.
[25] JACQUIN L, MOLTON P, DECK S, et al. An experimental study of shock oscillation over a transonic supercritical profile[C]//35th AIAA Fluid Dynamics Conference and Exhibit. Reston:AIAA, 2005.
[26] JACQUIN L, MOLTON P, DECK S, et al. Experimental study of shock oscillation over a transonic supercritical profile[J]. AIAA Journal, 2009, 47(9):1985-1994.
[27] GROSSI F, BRAZA M, HOARAU Y. Prediction of transonic buffet by delayed detached-eddy simulation[J]. AIAA Journal, 2014, 52(10):2300-2312.
[28] HUANG J B, XIAO Z X, LIU J, et al. Simulation of shock wave buffet and its suppression on an OAT15A supercritical airfoil by IDDES[J]. Science China Physics, Mechanics and Astronomy, 2012, 55(2):260-271.
[29] FUKUSHIMA Y, KAWAI S. Wall-modeled large-eddy simulation of transonic airfoil buffet at high Reynolds number[J]. AIAA Journal, 2018, 56(6):2372-2388.
[30] ZHAO Y, FORHAD A. A general method for simulation of fluid flows with moving and compliant boundaries on unstructured grids[J]. Computer Methods in Applied Mechanics and Engineering, 2003, 192(39-40):4439-4466.
[31] BRUCE P J K, COLLISS S P. Review of research into shock control bumps[J]. Shock Waves, 2015, 25(5):451-471.
CJA