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本文以开发低雷诺数下优良气动特性翼段为目标,对以NACA63_4-021翼型为基型的光滑翼段和仿生翼段模型,在0°~90°攻角,雷诺数Re=2×10~5的条件下,采用五分量测力天平和粒子图像测速仪(PIV)于直流风洞中分别测量升阻力等翼型气动特性和流场特性.结果表明:仿生翼段的失速特性更为平缓,失速后升力系数提高21%,升阻比增加23%,阻力系数减小3%,在30°~80°大攻角区具有一定增升减阻效果。作用机理:改变了光滑翼型的边界层分离模式,加强了边界层内部和外部势流的动量交换,进而增强了吸力面流场抵御逆压梯度的能力,使得流动分离推迟,失速得以延缓。
In this paper, aiming at the development of the aerodynamic characteristics of the low wing Reynolds number aerofoils, the smooth wing section and the bionic wing section model based on the NACA63_4-021 airfoil are studied. The Reynolds number Re = 2 × The aerodynamic characteristics and flow field characteristics of airfoil, such as lift resistance, were measured in a DC wind tunnel using a five-component force-measuring balance and a particle image velocimeter (PIV) under the conditions of 10-5.The results show that the stall characteristics More smooth, after the stall lift coefficient increased by 21%, lift resistance ratio increased by 23%, the drag coefficient decreased by 3%, 30 ° ~ 80 ° angle of attack with a certain increase drag reduction effect. Mechanism: The smooth boundary layer separation mode is changed, the momentum exchange between the internal and external boundary layers is strengthened, and the ability of the suction flow field to resist the reverse pressure gradient is enhanced. The flow separation is delayed and the stalling is delayed.