Transverse vortex-induced vibration (VIV) of a two-dimensional, elliptic cylinder with various aspect ratios and stiffness is studied. The cylinder is elastically mounted and heated, and the flow direction is aligned with the direction of the thermal-induced buoyancy force. The transverse VIV can be suppressed as the thermal control parameter, the Richardson number ($Ri$), increases. Complete suppression is achieved when $Ri$ is above a critical value, $R{i}_c$. The critical $Ri$ increases with the aspect ratio. For elliptic cylinders in lock-in regime, $R{i}_c$ is the optimal value since both VIV suppression and the minimum drag are achieved. A maximum drag reduction of 50.2% was found for an aspect ratio (AR) 2 cylinder at $R{i}_c$. For VIV in the unsynchronized regime, even though the thermal control can suppress the vibration, the corresponding drag coefficient, however, can be higher than that in the case of without control. Therefore, the thermal control is more effective to suppress VIV in the lock-in regime. When suppressing the vibration of an AR 4 cylinder in the flexible VIV regime using thermal control, we observed the cross-2S vortex mode, in which the typical 2S vortices generated at near field can cross the centerline and switch sides after a few vibration cycles.

研究了具有不同长宽比和刚度的二维椭圆圆柱的横向涡激振动（VIV）。缸体被弹性地安装并被加热，并且流动方向与热致浮力的方向对准。可以将横向VIV作为热控制参数，理查森数（$\mathrm{[R}\mathrm{一世}$），增加。当完全抑制时 $\mathrm{[R}\mathrm{一世}$ 高于临界值， $\mathrm{[R}{\mathrm{一世}}_C$。关键 $\mathrm{[R}\mathrm{一世}$随着长宽比增加。对于处于锁定状态的椭圆圆柱， $\mathrm{[R}{\mathrm{一世}}_C$因为同时实现了VIV抑制和最小阻力，所以它是最佳值。对于宽高比（AR）2的圆柱体，最大减阻为50.2％ $\mathrm{[R}{\mathrm{一世}}_C$。对于处于非同步状态的VIV，即使热控制可以抑制振动，但是相应的阻力系数也可以比无控制情况下的阻力系数更高。因此，热控制在锁定状态下更有效地抑制了VIV。当使用热控制在柔性VIV模式下抑制AR 4气缸的振动时，我们观察到了2S交叉涡流模式，在该模式中，在近场产生的典型2S涡流在经过几个振动周期后可以越过中心线和切换侧。