Controlled transients of flow reattachment over stalled airfoils

被引:126
作者
Amitay, M [1 ]
Glezer, A
机构
[1] Georgia Tech Res Inst, ATAS Lab, Atlanta, GA 30318 USA
[2] Georgia Inst Technol, Sch Mech Engn, Atlanta, GA USA
关键词
synthetic jets; controlled reattachment and separation; actuation frequency; flow transients;
D O I
10.1016/S0142-727X(02)00165-0
中图分类号
O414.1 [热力学];
学科分类号
摘要
The flow transients associated with controlled reattachment and separation of the flow over a stalled airfoil are investigated in wind tunnel experiments. Control is effected using surface-mounted synthetic jet actuators that are typically operated at frequencics, which are at least an order of magnitude higher than the characteristic shedding frequency of the airfoil. While at these actuation frequencies the circulation (and hence the lift) of the attached flow is nominally time invariant, actuation at lower frequencies that are commensurate with the shedding frequency results in a Coanda-like attachment of the separated shear layer, organized vortex shedding and substantial oscillation of the circulation. The transients associated with flow reattachment and separation are investigated using amplitude modulation of the actuation waveform. Phase-locked measurements of the velocity field in the near wake of the airfoil and corresponding flow visualizations show that the transients that are associated with the onset of reattachment and separation are accompanied by the shedding of large-scale vertical structures and oscillations of the circulation. Pulsed modulated actuation of the actuation waveform is used to capture these transient effects and augment the increase in lift that is obtained by conventional time-harmonic actuation. (C) 2002 Elsevier Science Inc. All rights reserved.
引用
收藏
页码:690 / 699
页数:10
相关论文
共 17 条
[1]  
Ahuja K. K., 1984, AIAA Paper No. 84-2298
[2]   Role of actuation frequency in controlled flow reattachment over a stalled airfoil [J].
Amitay, M ;
Glezer, A .
AIAA JOURNAL, 2002, 40 (02) :209-216
[3]   Aerodynamic flow control over an unconventional airfoil using synthetic jet actuators [J].
Amitay, M ;
Smith, DR ;
Kibens, V ;
Parekh, DE ;
Glezer, A .
AIAA JOURNAL, 2001, 39 (03) :361-370
[4]  
AMITAY M, 2001, 2 INT S TURB SHEAR F
[5]  
Amitay M, 1999, 991001 AIAA
[6]  
AMITAY M, 1999, P 3 ASME JSME JOINT
[7]   FORCING LEVEL EFFECTS OF INTERNAL ACOUSTIC EXCITATION ON THE IMPROVEMENT OF AIRFOIL PERFORMANCE [J].
CHANG, RC ;
HSIAO, FB ;
SHYU, RN .
JOURNAL OF AIRCRAFT, 1992, 29 (05) :823-829
[8]  
DONOVAN JF, 1998, 980210 AIAA
[9]  
HONOHAN AM, 2000, 20002401 AIAA
[10]   CONTROL OF WALL-SEPARATED FLOW BY INTERNAL ACOUSTIC EXCITATION [J].
HSIAO, FB ;
LIU, CF ;
SHYU, JY .
AIAA JOURNAL, 1990, 28 (08) :1440-1446