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众所周知,风洞试验中的飞机模型,尤其是带有大展弦比机翼的模型有时会出现翼梢振动现象,振动模式主要表现为翼梢沉浮和俯仰形式,以致影响实验结果的精度和可靠性。选取相对厚度较小的NACA0008翼型,在求解非定常Navier-Stokes方程的基础上,采用改进的无限插值理论和绕翼型的C型网格,模拟风洞实验中模型振动条件下的流场,研究振动模式及其不同耦合对流场、尤其是大迎角流场的影响,并考虑了模型弹性轴不同位置对结果的影响。研究结果表明:在临近传统定常失速迎角的大迎角条件下,翼型的振动可以引起翼型大尺度的分离,导致翼型失速的提前发生;振动在不同的相位滞后条件下,对翼型流场的分离程度不尽相同。
As we all know, the wind tunnel test aircraft model, especially with a large aspect ratio wing sometimes appear wing vibration phenomenon, the main vibration mode wing tip ups and downs and pitch form, so as to affect the accuracy and reliability of the experimental results Sex. Based on solving the unsteady Navier-Stokes equations, the NACA0008 airfoil with relatively small thickness is chosen and the improved infinite interpolation theory and the C-shaped grid around the airfoil are used to simulate the flow field under the model vibration in the wind tunnel experiment , The effects of different modes of vibration and their coupling on the flow field, especially the flow field at high angles of attack, were studied. The effects of different locations of the model elastic axis on the results were also considered. The results show that under the condition of high angle of attack near the traditional steady-state stalling angle of attack, the vibration of the airfoil can cause the large-scale separation of the airfoils, leading to the premature occurrence of the airfoil stall. Under different phase lag conditions, Type flow field of the degree of separation is not the same.