FLUIDELELASTIC INSTABILITY, VORTEX-INDUCED VIBRATION AND SYMMETRY BREAKING IN HELICAL ARRAYS OF CYLINDERS SUBJECTED TO CROSS-FLOW

横流圆柱螺旋阵列中的流体弹性不稳定性、涡激振动和对称性破缺

• 批准号: RGPIN-2020-06955
• 负责人: mureithi, njuki
• 金额: $ 2.33万
• 依托单位: École Polytechnique de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=754482
• 关键词: FLUIDELELASTIC; INSTABILITY; VORTEX; INDUCED; VIBRATION

The proposed research program investigates the problem of fluid-structure interaction in large systems consisting of multiple components interconnected with high spatial symmetry. The physical system under consideration is an array of helical tubes subject to external flow parallel to the helix axis. Helical geometry tube arrays are ideal for compact heat-exchanger design. Compared to straight or U-bend tube heat exchangers, helical tube heat exchangers have a much larger heat transfer surface per unit volume of space occupied by the heat exchanger. The recent technological developments and focus on small-scale energy generation systems (e.g. small modular nuclear reactors, thermal solar power systems) is driving renewed interest in fluid-structure interaction in helical geometry heat exchangers. In addition to industrial applications, the highly complex flows in helical tube arrays presents some challenging fundamental research problems in the area fluid-structure interaction. The strong auto-coupling of the helical tubes can lead to enhanced instability due to strong fluid-structure correlation along the helix. Strong vortex-induced vibration due to vortex shedding synchronization along the helix is also expected to be an important problem. The primary objective of the proposed research is to investigate the fluid-structure interaction dynamics of helical geometry structures subjected to flow parallel to the helix axis. The primary flow-excitation phenomena expected are vortex-induced vibration and fluidelastic instability. While these phenomena are fairly well understood for arrays of straight tubes the helical tube geometry changes the FSI problem in a non-trivial manner. The proposed research program will address several related fluid-structure interaction (FSI) problems. The first is the problem of fluidelastic instability in helical tube array geometries. Experimental testing and theoretical model development will be done.  The second  FSI problem relates to vorticity shedding and Vorticity Induced Vibrations (VIV). This problem will be addressed using computational fluid dynamics  (CFD) and experimental methods. Experimental flow visualization using PIV techniques will also be performed in the helical tube array.  The research program aims to address the fundamental mechanisms underlying flow-induced vibrations in helical geometry tube arrays. These arrays are the key component of highly compact helical geometry heat exchangers and steam generators. The proposed research program is expected to contribute to the development of new methods for the stability analysis of these industrial components.

提出的研究计划研究了大型系统中流体结构相互作用的问题，这些系统由多个与高空间对称性相互连接的组件组成。所考虑的物理系统是平行于螺旋轴的外部流动的螺旋管阵列。螺旋几何管阵列是紧凑的热交换器设计的理想选择。与直接或U型管热交换器相比，螺旋管热交换器的热交换器每单位量的空间量的热传递表面更大。最近的技术发展和关注小型能源产生系统（例如，小型模块化核反应堆，热太阳能系统）正在推动对螺旋几何热交换器中流体结构相互作用的新兴趣。除了工业应用外，高度复杂的螺旋管阵列中的流动还提出了一些挑战的基本研究问题，该地区的流体结构相互作用。螺旋管的强大自动耦合可能会导致由于螺旋沿螺旋沿强大的流体结构相关性而增强的不稳定性。由于沿螺旋的涡流脱落同步引起的强涡流引起的振动也有望是一个重要的问题。拟议的研究的主要目标是研究螺旋几何结构的流体结构相互作用动力学，该动力学与螺旋轴平行的流动。预期的主要流动兴奋现象是涡旋诱导的振动和流体弹性的不稳定性。尽管这些现象对于直管阵列的螺旋管几何形状以非平凡的方式改变了FSI问题，但对这些现象进行了充分的理解。拟议的研究计划将解决螺旋管阵列几何形状中的几种相关流体弹性不稳定性。将进行实验测试和理论模型开发。第二个FSI问题涉及涡度脱落和涡度诱导的振动（VIV）。该问题将使用计算流体动力学（CFD）和实验方法解决。使用PIV技术的实验流可视化也将在螺旋管阵列中进行。该研究计划旨在解决螺旋几何管阵列中流动引起的振动的基本机制。这些阵列是拟议的研究计划预计将有助于开发这些工业组件稳定性分析的新方法的关键。