二维振荡翼型俯仰和升沉耦合运动的水动力性能分析

Hydrodynamic performance analysis of pitching and heaving coupling motion for two dimensional oscillating airfoil

为了分析二维翼型在非定常状态下俯仰和升沉耦合运动的水动力性能,本文基于RANS方法,运用重叠网格技术,以NACA 0020翼型为研究对象,分析了翼型耦合运动与单一运动的区别以及不同振荡频率对翼型耦合运动时升力、阻力和涡流的影响。结果表明:二维翼型做耦合运动时,振荡频率越小,俯仰运动效应大于升沉运动效应,振荡频率越大,升沉运动效应加强;翼型的振荡频率越大,翼面上涡的分离越迟,翼型发生失速的时间越晚;脱落涡的范围越广,翼型的升力系数和阻力系数越大。

In order to analyze the hydrodynamic performance of the two dimensional airfoil in the unsteady state of the pitching and heaving coupling motion,based on the RANS method,the difference between the coupled motion and the single motion of the airfoil as well as the influence of the different oscillation frequencies on the lift,resistance and vortex in the coupled motion of the airfoil are analyzed by using the overlapping grid technique and taking the NACA 0020 airfoil as the research object.The results show that when the two-dimensional airfoil performs a coupling motion,the smaller the oscillation frequency is,the greater the pitching motion effect is than the heaving motion effect,and the larger the oscillation frequency is,the stronger the heaving motion effect is.When the airfoil oscillation frequency becomes larger,both the separation of the vortex on the airfoil and the stall of the airfoil tend to be later.With the range of the exfoliate vortex becoming wider,the lift and drag coefficients of the airfoil become larger.