喷射气流对横向振荡圆柱体尾流抑制的影响

Influence of jet airflow on the suppression of transverse oscillation cylinder wake flow

对雷诺数Re=1200条件下的圆柱在均匀来流中横向受迫振荡的尾流控制问题进行数值模拟分析.通过尾部加喷射气流对不同旋涡脱落模式进行尾流控制,通过对圆柱在不同振幅和振荡频率下涡脱落情况进行观察研究,最终在无量纲振荡频率feD/V=0.21,振幅比A/D=0.5情况下发现了2S旋涡脱落模式并通过在柱体尾部施加不同速度的喷射气流对其进行控制;在feD/V∞=0.189,A/D=1.5情况下发现了P+S旋涡脱落模式并在柱体尾部施加不同速度的喷射气流对其进行控制.涡量图和功率频谱图结果表明,在2S模式下,喷射气流对旋涡脱落抑制效果明显,尤其当喷射速度Ve=5m/s时效果显著.而在P+S模式下,当喷射速度Ve=2.5m/s时旋涡脱落抑制效果较好,而当喷射速度Ve分别为5m/s和7.5m/s时,抑制效果一般.

Numerical simulation of the wake control problem of the cylinder in the uniform flows with the Reynolds number Re= 1200 was analyzed. Different wake vortex shedding modes were controlled by the tail jet stream. The vortex shedding condition was observed under different amplitude and oscillation frequency. The mode of 2S vortex shedding was observed and controlled under the condition of amplitude ratio A/D=0. 5 non- dimensional oscillation frequencies feD/V∞= 0. 21. The P ＋ S vortex shedding mode was observed and controlled under the condition of amplitude ratio A/D= 1.5 non-dimensional oscillation frequencies feD/V∞0. 189. The result of the vorticity and the velocity power spectrum show that the jet has obvious inhibit effect on 2S mode vortex shedding, especially when the velocity is 5 m/s. In the case of the P＋ S mode, when the jet velocity is 2.5 m/s, the inhibition effect in the jet velocity of 2.5 m/s is better than that of 5 m/s and 7.5 m/s.