CAJ | 학술논문

采用倾斜出口合成射流激励器对NACA633-421三维直机翼进行分离流主动流动控制，天平测力结果表明合成射流可以有效地控制机翼流动分离，提升最大升力系数10．4％，推迟失速迎角4°。运用边界层测试技术及粒子图像测速系统（PIV）对合成射流分离流控制机制进行研究分析，结果表明，控制后边界层速度型变得“饱满”，形状因子减小，其底层能量增加，抵抗逆压梯度能力增强。瞬态及时均化PIV测试流场图进一步证明合成射流向主流进行动量注入及掺混后，主流附着机翼表面，翼面附近流体湍流动能和雷诺剪切应力增加，分离点向下游推迟，流动分离得到抑制。
채용경사출구합성사류격려기대NACA633-421삼유직궤익진행분리류주동류동공제，천평측력결과표명합성사류가이유효지공제궤익류동분리，제승최대승력계수10．4％，추지실속영각4°。운용변계층측시기술급입자도상측속계통（PIV）대합성사류분리류공제궤제진행연구분석，결과표명，공제후변계층속도형변득“포만”，형상인자감소，기저층능량증가，저항역압제도능력증강。순태급시균화PIV측시류장도진일보증명합성사류향주류진행동량주입급참혼후，주류부착궤익표면，익면부근류체단류동능화뢰낙전절응력증가，분리점향하유추지，류동분리득도억제。
Active flow control on a three-dimensional NACA633-421 airfoil has been investiga-ted experimentally using beveled-slit-synthetic-j et-actuator (BSSJA).Balance force measurement results show that the synthetic jet can control the flow separation effectively,improve the maxi-mum lift coefficient by 10.4% and increase the stall angle of attack by 4°.Both boundary layer velocity measurement and particle image velocimetry (PIV)technology have been performed un-der selected experimental conditions to investigate the mechanism of synthetic jet flow control. Results reveal that the shape factor of boundary layer velocity profile decreases with BSSJA con-trol and the promotion of the power of the boundary layer is responsible for the control effect. The instantaneous flow maps and ensemble-averaged PIV results reveal that synthetic j et tends to enhance the flow dilution and transfer the mass flux so that the separated flow could attach to the wall of NACA633-421 airfoil again.In addition,the turbulent kinetic energy (TKE)and Reyn-olds stress are increased near the wall compared to the situation without control.