摘要
本文研究了圆柱尾迹中振荡翼型的动力学特性,通过浸入式边界方法结合自适应网格技术对雷诺数为1100的二维模型开展了数值模拟计算,重点关注圆柱翼型间距和振荡频率这两个关键参数的影响.文中给出了翼型动力学响应随上述两个参数的变化规律,包括流动作用力、频率特征以及翼型与流动之间的能量交换过程,结果表明圆柱尾迹能够显著改变翼型阻力的大小,并且对通过翼型升力所产生的能量交换过程具有重要影响.在某些特定流动工况下,翼型振荡会与尾迹之间呈现出1:1,1:2和1:3不同的同步模式.值得注意的是,1:2同步对应着一种非对称的涡脱落形态,在此工况下,即使翼型的振荡和上游圆柱尾迹都存在明显的周期性,翼型上依然存在非零的时均升力及力矩.此外由于圆柱尾迹与翼型振荡之间的强烈非线性干涉,在翼型响应中出现了新的频率条带,该条带满足非线性频率叠加关系.本文还发现振荡幅值对于同步现象具有重要影响.
The dynamic performance of an oscillating airfoil subjected to the wake of a circular cylinder is studied in this paper.Two-dimensional numerical simulations are conducted at Re=1100 by using an immersed boundary method together with the adaptive mesh refinement technique.The effects of two parameters,the gap between the cylinder and the airfoil and the oscillation frequency,are of particular interest to the present study.Therefore,dynamic responses are presented as functions of the two parameters,including the fluid forces,the associated frequency characteristics,and the energy exchange between the airfoil and the fluid.The results show that the cylinder wake can significantly reduce the drag as well as the energy extraction of the lift on the airfoil.Different synchronization behaviors between the airfoil’s oscillation and the wake pattern have been observed for some specific cases,i.e.,the 1:1,1:2 and 1:3 patterns.Remarkably,the 1:2 pattern is associated with an asymmetric vortex shedding pattern,which can further result in non-zero time-averaged lift and moment on the airfoil even though both the upstream vortices from the cylinder and the oscillation of the airfoil are periodic.Due to the strong nonlinear interaction between the cylinder wake and the airfoil’s oscillation,new frequency branches associated with nonlinear frequency superposition are formed in the responses of the airfoil and their characteristics have been demonstrated.The present study also finds that the oscillation amplitudes are important in determining the synchronization behavior.
作者
王卓
杜林
孙晓峰
Zhuo Wang;Lin Du;Xiaofeng Sun(Aeroengine Research Institute,Beihang University,Beijing,100191,China;School of Energy and Power Engineering,Beihang University,Beijing,100191,China)
基金
the National Natural Science Foundation of China(Grant No.52022009)
the Science Center for Gas Turbine Project of China(Grant No.P2022-A-II-003-001)
Key Laboratory Foundation,China(Grant No.2021-JCJQ-LB-062-0102)
the Fundamental Research Funds for the Central Universities of China.
