后退式微型后缘装置对机翼增升和流动特性影响的实验研究

Experimental investigation on aerodynamics and flow structures of a wing with mini-trailing edge device

实验测量了加装"后退式微型后缘装置"的NACA23012机翼在低雷诺数下的升/阻力、力矩和翼尖涡速度分布,并根据实验测量结果研究了该装置对机翼气动特性和翼尖涡结构的影响。实验升/阻力由六分量风洞天平测量,翼尖涡速度分布用七孔探针扫描获得,自由来流速度为15m/s,以弦长为特征长度的雷诺数为1×105。结果表明:与NACA23012原型相比,加装"后退式Mini-TED"后机翼升力显著增加,失速攻角减小;而使机翼阻力比原型翼在小攻角时略有增加,但在大攻角时有更明显的增长;在中高升力系数的情况下,机翼升阻比明显大于原型机翼;Mini-TED使得气动中心后移,相比于原型翼,机翼低头力矩以较为平稳的趋势增加,使机翼在中等攻角和大攻角情况下的俯仰稳定性得到提高;翼尖涡测量结果显示,后退式Mini-TED机翼在相同的正攻角下具有更大的上下翼面压力差,诱导出更强的翼尖涡和下洗运动,从而使得诱导阻力增加,总阻力也随之增加。

The experimental study on the lift/drag forces,pitching moment and tip vortices of a NACA23012 wing mounted with a Rearward Mini-TED at low Reynolds number is intro-duced.The influences of the flow structure to the aerodynamic characteristics of the wing are dis-cussed.The experiment was conducted in a low speed wind tunnel.The aerodynamic loads were measured using a 6-components transducer,and the velocity fields of the tip vortices were meas-ured by a seven-hole probe.The speed of free stream is 15 m/s,and the Reynolds number is Re =1.0 × 10 5 based upon the chord length of the wing.Compared with those of the prototype NACA23013 wing,the lift force of the one with Rearward Mini-TED wing increases significantly and the stalling angle of attack decreases.The Mini-TED leads to a slight increase of the drag force at the small angel of attack and a significant increase for larger angle of attack compared to that of prototype NACA23012 wing.The lift-to-drag ratio is larger than that of the clean NACA23012 wing at higher lift coefficient range.Meanwhile,the nose-down pitching moment is increased due to the downstream shifting of the aerodynamic center,the stability of the wing is improved at higher angle of attack.The high pressure distribution on the lower wing surface caused by Mini-TED leads to the increasing of intensity of the tip vortices,and the down-wash flow is enhanced,as a result the induced drag as well as the total drag are increased.