Non-uniform Cross Flow Induced Vibration of Tube Bundle Based on High-Speed Visual Measurement

The study investigates cross flow-induced vibration under conditions of transverse flow nonuniformity through a visualization-based experimental approach. Flow-induced vibration characteristics of a two-span rotated triangular tube bundle, supported by two tube support plates (TSPs), are examined. Tube positions at the upper extremity are captured using a high-speed camera. Findings reveal that the tube bundle exhibits a higher susceptibility to fluid elastic Instability (FEI) when subjected to non-uniform cross flow induced by a one-third opening baffle, in contrast to a uniform hole baffle configuration. With the one-third opening baffle configuration, substantial variations in tube vibration amplitudes are observed among different tubes. and the tube bundle can be divided into three kinds of regions, i.e. the severe vibration region, transition region and reversed flow region. The severe vibration region encompasses the central tubes within the three columns directly facing the opening of the baffle. This region serves as the initiation zone for FEI and warrants particular design considerations.