Numerical study of the effect of periodic jet excitation on cylinder aerodynamic instability
Numerical study of the effect of periodic jet excitation on cylinder aerodynamic instability
复制标题
周期性射流激励对气缸气动不稳定性影响的数值研究
DOI：
10.12989/was.2002.5.2_3_4.141
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
T. Nomura
中科院分区：
文献类型：
--
作者：
S. Hiejima;T. Nomura
采用ALE有限元方法对具有剪切层不稳定频率的周期性射流激励下的振荡圆柱绕流进行了数值模拟。激励从圆柱表面的两点施加到流动上。数值结果表明，具有剪切层失稳频率的激励可以减小负阻尼，从而稳定振荡圆柱的气动特性。升力相位的变化对稳定气缸空气动力学是重要的。升力相位的变化是由具有剪切层不稳定频率的周期激励诱导的涡合并引起的，而涡合并是由于分离剪切流中周期激励的高增长率、波数的快速增加和相速度的降低。
Numerical simulations based on the ALE finite element method are carried out to examine the aerodynamics of an oscillating circular cylinder when the separated shear flows around the cylinder are stimulated by periodic jet excitation with a shear layer instability frequency. The excitation is applied to the flows from two points on the cylinder surface. The numerical results showed that the excitation with a shear layer instability frequency can reduce the negative damping and thereby stabilize the aerodynamics of the oscillating cylinder. The change of the lift phase seems important in stabilizing the cylinder aerodynamics. The change of lift phase is caused by the merger of the vortices induced by the periodic excitation with a shear layer instability frequency, and the vortex merging comes from the high growth rate, the rapid increase of wave number and decrease of phase velocity for the periodic excitation in the separated shear flows.