A Hybrid CFD and Semi-analytical Model for Streamwise Fluidelastic Instability of Paraller Triangular Tube Bundles

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] This paper employs computational fluid dynamics (CFD) to simulate the flow field around a single flexible tube within a rigid, parallel triangular tube array under lateral flow conditions.

Time delay and decay functions within the dynamic channel were extracted through post-processing and integrated into a semi-analytical time-domain model to represent fluid-elastic forces in the drag direction. Utilizing this CFD-semi-analytical hybrid model, a time-domain analysis of drag-direction flow-induced instability in the tube bundle was conducted. The predicting critical velocity threshold showed stronggood agreement with existing literature and experiment.

[Conclusions] These findingsOur efforts provide valuable insights for the design of heat transfer tube bundles in steam generators, flow-induced vibration analysis, and fretting wear assessment.