Flow-Visualization of a Prototypical Helical Coil Test Bundle Undergoing Vibrations

Abstract Flow-Induced Vibrations (FIVs) have been of the upmost interest in the engineering community due to their large role in safety and reliability design in heat exchangers. This has especially been true in the nuclear sector as focuses have shifted to Small Modular Reactors (SMRs). These reactors aim to decrease the volumetric footprint of reactors, while maintaining a reasonable power output. To achieve this more compact heat exchangers and faster flow rates are implemented. These changes lead to larger vibrational amplitudes in the system and must be accounted for. This study utilizes Particle Image Velocimetry (PIV) to provide flow visualization of a prototypical section of a Helical Coil Steam Generator (HCSG) with a clockwise, counterclockwise tube rotation undergoing vibrations. The bundle of interest utilizes a canti-levered attachment approach in order to lower the natural frequency of the system. The flow field statistics are studied intensively in order to gain greater understanding of the FIV phenomenon. Several advanced analysis techniques are utilized in this pursuit such as: Proper Orthogonal Decomposition (POD), Wavelet, and spectral analysis.

Flow-Visualization of a Prototypical Helical Coil Test Bundle Undergoing Vibrations Conference Paper