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| 高阻尼高雷诺数下串列双圆柱尾流激振特性数值研究 |
| Numerical Investigation on High Damping, High Reynolds Wake-induced Vibrations of Cylinders in Tandem Arrangement |
| 投稿时间：2019-09-16 修订日期：2019-10-25 |
| DOI： |
| 中文关键词: 涡激振动 驰振 尾流结构 高阻尼 高雷诺数 |
| 英文关键词: Vortex-Induced Vibration Galloping Wake Structure High Damping High Reynolds Numbers |
| 基金项目:国家自然科学基金项目（面上项目，重点项目，重大项目） |
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| 中文摘要: |
| 流激振动能量转换装置多柱体阵列涉及复杂的尾流激振问题，其运行时柱体振动具有高阻尼、高雷诺数特征。本文基于雷诺平均N-S方程，结合SST k-ω湍流模型和任意拉格朗日-欧拉流固耦合动网格控制方法建立串列双圆柱尾流激振数值模型，重点考察小间距比（两圆柱中心距离与圆柱外径之比）、高阻尼、高雷诺数条件下串列双圆柱的尾流激振特性。计算时两圆柱中心距离分别为1.5、2、3、4、20倍直径，振动圆柱阻尼比为0.12，计算雷诺数范围为17000~98000。对柱体的振动响应，升力系数和尾流形态进行了分析，计算结果表明，不同间距条件下下游圆柱振动表现为驰振、分离的涡激振动-驰振、涡激振动等不同的振动特性，振动特性的不同与上游圆柱后面的尾流形式及重附于下游圆柱的方式密切相关，S/D=1.5、2时剪切层交互式地重附于下游圆柱，使下游圆柱振动表现为驰振；S/D=3和4时，恒定式的剪切层重附抑制了下游圆柱的振动，导致分离的涡激振动-驰振振动形式的出现。 |
| 英文摘要: |
| The Flow-Induced Vibrations (FIVs) based hydrokinetic energy converter is a new concept to generate clean renewable electricity from ocean/river currents. High-Reynolds and high damping are required to operate the energy converter in ocean/river currents. Wake-induced vibration is a complex flow-structure interaction problem which is concerned in flow-induced vibrations of multi-cylinder. This work presents an extensive study of wake-induced vibrations of two closely spaced circular cylinders in tandem arrangement at high-Reynolds and high damping conditions using a computational fluid dynamics approach. The fluid flow is modeled using two-dimensional Reynolds-Averaged Navier–Stokes equations in conjunction with the SST k-ω turbulence model. An Arbitrary Lagrange-Euler (ALE) fluid-field model is used to simulate the fluid-solid interactions. The upstream cylinder is fixed and the downstream one is movable. Five spacing ratios were examined, i.e., S/D = 1.5, 2, 3, 4 and 20 (S is the gap spacing between the centers of the two cylinders; D is the diameter of cylinder). The Reynolds number is from 17000 to 98000, and the damping ratio is kept a constant of 0.12. Depending on the cylinders’ separation, the cylinder exhibited a galloping, or a separated vortex-resonance and galloping, or a vortex-resonance. It is found that the vortex shedding behind the upstream cylinder has strong influence in changing vortex shedding behind the downstream one, and then affects the vibration characteristics of the downstream one. |
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