平行三角形管束曳力方向流弹失稳的CFD-半解析混合模型

Background] Fluidelastic instability (FEI) of heat transfer tube bundles under cross-flow conditions represents a critical safety concern in steam generator design, as it may result in tube wear and rupture. While most existing studies have focused on FEI in the lift direction, relatively limited attention has been given to the drag direction. However, recent findings suggest that drag-induced FEI also poses a substantial risk. [Purpose] This study aims to investigate drag FEI using a hybrid CFDsemi-analytical model and determine its critical velocity threshold. [Methods] A two-dimensional CFD model of a single flexible tube in a rigid parallel-triangular array was developed. Transient simulations under cross-flow were performed to capture flow field evolution. Flow channel images were post-processed to extract time delay and decay functions. These functions were embedded into a semi-analytical time-domain model to analyze fluidelastic response. [Results] The predicting critical velocity threshold showed strong agreement with existing literature and experiment. [Conclusions] These findings provide valuable insights for the design of heat transfer tube bundles in steam generators, flow-induced vibration analysis, and fretting wear assessment.