A Precise Approach to Predict Transonic Wing Buffet Boundary
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摘要: 在用定常气动参数对机翼跨音速抖振边界进行仿真预计时,由于有些流场条件下的气动参数在抖振始发攻角附近变化不明显,给抖振边界的准确预计带来困难。因而提出了确定抖振始发攻角的气动参数曲线最大曲率法,通过求解机翼不同攻角下的定常流场N-S方程,获得机翼的升力系数、俯仰力矩系数和后缘压力系数,用四次多项式分别对这些气动参数进行曲线拟合,得到各种曲线的曲率方程,由曲率的极大值点确定抖振始发攻角。用该方法对一个NACA0012翼型在0.775马赫下的抖振始发攻角的仿真预计结果与风洞试验得到的抖振始发攻角对比表明具有较高的预计精度。Abstract: In the numerical prediction of transonic wing buffet boundary( i. e. buffet onset incidence) using steady aerodynamic parameters,it is difficult to determine the buffet boundary according to the aerodynamic parameters near the buffet onset incidence because the variations of these parameters are not obvious. A precise approach,called maximum curvature method,to predict the transonic wing buffet onset incidence is proposed. The flow field is simulated by solving steady N-S equation at different wing incidence,and the lifting coefficient curve,pitching moment coefficient curve and the trailing edge pressure coefficient curve are acquired and each curve is fitted by a quartic polynomial to get its curvature equation. Then the buffet onset incidence can be determined by solving its extremum. The transonic buffet onset incidence of a NACA 0012 airfoil at Mach 0. 775 is predicted by the present method. And the predicted transonic buffet onset incidence is compared to that obtained by wind tunnel tests cited from literature and good agreement is achieved. It is illustrated that the method can predict wing transonic buffet boundary with high precision because it utilizes more information from aerodynamic parameters in the vicinity of buffet onset incidence.
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Key words:
- airfoils /
- buffeting /
- computational fluid dynamics /
- computer simulation
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[1] Pearcey H H. Some effects of shock-induced separation of turbulent boundary layers in transonic flow past aerofoils[A].1955. [2] lovnovich M,Raveh D E. Reynolds-averaged navier-stokes study of the shock-buffet instability mechanism[J].AIAA Journal,2012,(03):80-89. [3] Pearcey H H,Osborne J,Haines A B. The interaction Between Local Effects at the Shock and Rear Separation-A Source of Significant Scale Effects in Wind-Tunnel Tests on Airfoils and Wings[R].CP-35,AGARD,1968. [4] Chung I,Lee D,Reu T. Prediction of transonic buffet onset for airfoils with separation bobble using steady approaches[J].Journal of Aircraft,2003,(04):795-797. [5] McDevitt J B,Okuno A F. Static and Dynamic Pressure Measurements on a NACA0012 Airfoil in the Ames High Reynolds Number Facility[R].NASA TP-2485,1985. [6] Barth T J,Jespersen D C. The design and application of upwind schemes on unstructured meshes[A].1989. [7] Menter F R. Two-equation eddy-viscosity turbulence models for engineering applications[J].AIAA-Joumal,1994,(8A):1598-1605. [8] 郭同庆,董璐,陆志良. 跨音速机翼抖振初始迎角N-S方程定常计算分析[J].航空学报,2008,(04):840-844. [9] Cbopra S C,Canale R P. Numerical Methods for Engineers[M].New York:McGraw-Hill,1998.454-455. [10] 同济大学数学教研室. 高等数学(上册)[M].北京:高等教育出版社,1996.210-211. [11] Pearcey H H. A Method for the Prediction of the Onset of Buffeting and Other Separation Effects From Wind Tunnel Test on Rigid Methods[R].AGARD Report 223,1958. [12] Pesrcey H H,Holder D W. Simple Methods for the Prediction of Wing Buffeting Resulting From Bubble Type Separation[R].NPL AERO-REP-1024,National Physical Laboratory,1962.
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