悬垂取水管作为温差能发电平台等生产设施的核心构件，受到的关注与日俱增。悬垂连接双管结构较之单管有着更高的输送效率与更低的制造工艺要求，但是其涡激振动特性尚不明确。为此，本文开展了一系列悬垂连接双管模型试验，提出了一种针对大位移、小变形问题的涡激载荷识别方法，对比分析了双管与单管的涡激振动特性，得到的结论如下：在相同流速和方向下，悬垂双管和悬垂单管的涡激振动位移幅值在低流速时相似，但在高流速下存在差异；悬垂双管更容易表现出涡激振动的不稳定性，包括行波和多频响应等；双管结构可以采用与单管相同的斯特劳哈尔数进行涡激振动预报；此外，悬垂双管与悬垂单管在横向流动方向上的附加质量系数存在显著差异，其主要起到调节固有湿频率的作用，以使得双管发生涡激振动共振。

This study investigates vortex-induced vibration (VIV) characteristics of double free-hanging water transmission pipes, which are crucial for temperature difference energy harvesting platforms. Compared to single pipe, double pipes could offer higher transport efficiency and cost-effectiveness. In this paper, Model experiments were conducted to analyze VIV characteristics of the double free-hanging pipes and a method for identifying vortex-induced loads for large displacements and small deformations was proposed. A comparative analysis of the VIV characteristics of double free-hanging pipe and the single pipe was performed, leading to the following conclusions: Findings show that VIV displacement amplitudes of double free-hanging pipe are similar at low flow velocities but differ with those of single pipe at high velocities. The double free-hanging pipe is more prone to instability in VIV, including traveling waves and multi-frequency responses. And it is found that the VIV frequencies of double free-hanging pipe can be predicted by the same Strouhal number as the single pipe. Additionally, a significant difference in the added mass coefficient affects natural wet frequency adjustment for VIV resonance.