Abstract We numerically investigate the effect of thermal buoyancy on wake-induced vibration (WIV) of an elastically mounted square prism in the wake of an identical stationary prism. The upstream prism is heated at a prescribed temperature while the downstream prism is insulated and vibrates transversely to the flow direction. The Reynolds number, based on side of the prism is, Re = 100 and center-to-center distance is twice the side of the prism. Numerical simulations were performed for mass ratio m = 3, Prandtl number Pr = 7.1 and Richardson number Ri = [0, 1]. The reduced velocity UR is varied in a range from 4 to 30. The maximum oscillation amplitude occurs at UR = 5 at Ri = 1 as compared to Ri = 0. We report 50% reduction in the amplitude at Ri = 1 as compared to Ri = 0, implying WIV suppression due to the presence of thermal buoyancy. A complete suppression occurs at UR > 7 at Ri = 1. The lock-in (synchronization) region is narrow for both the cases. The downstream prism oscillates in phase to the lift force at Ri = 1 as ϕ remains 0∘, whereas at Ri = 0, ϕ changes abruptly from 0∘ to 180∘ and remains 180∘ for higher UR. We briefly discuss the influence of thermal buoyancy on wake dynamics. The present results provide insights to suppress the WIV by tailoring the thermal buoyancy for multiple bluff bodies in laminar flow.

中文翻译：

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热浮力诱导抑制尾流振动

摘要 我们数值研究了热浮力对相同固定棱镜尾流的弹性安装方形棱镜尾流诱导振动 (WIV) 的影响。上游棱镜在规定温度下被加热，而下游棱镜被隔热并横向于流动方向振动。基于棱柱边的雷诺数是，Re = 100，中心到中心的距离是棱柱边的两倍。对质量比 m = 3、普朗特数 Pr = 7.1 和理查森数 Ri = [0, 1] 进行了数值模拟。降低的速度 UR 在 4 到 30 的范围内变化。与 Ri = 0 相比，最大振荡幅度出现在 UR = 5 处，Ri = 1 处。我们报告说，与 Ri 相比，Ri = 1 处的幅度减小了 50% = 0，意味着由于热浮力的存在，WIV 抑制。完全抑制发生在 UR > 7 和 Ri = 1 处。这两种情况的锁定（同步）区域都很窄。下游棱镜在 Ri = 1 处与升力同相振荡，因为 ϕ 保持 0∘，而在 Ri = 0 处，ϕ 从 0∘ 突然变化到 180∘ 并且保持 180∘ 以获得更高的 UR。我们简要讨论了热浮力对尾流动力学的影响。目前的结果为通过调整层流中多个钝体的热浮力来抑制 WIV 提供了见解。