Fluid-Structure Interaction of a Steam Generator Tube in a Cross-Flow Using Large-Eddy Simulation

The behavior of a steam generator tube in a cross flow is examined by coupling the ABAQUS structural analysis code to Large-Eddy Simulation (LES) within the FLUENT Computational Fluid Dynamics solver. The moving tube is assumed to be within an infinite staggered array of other tubes, the centers being separated in the streamwise direction by 1.31 times the tube diameter and in the cross-stream direction by 2.73 times the tube diameter of 0.688 inches. The Reynolds number based upon total mass flow and one tube diameter is 1.0 × 10⁵, indicating a transcritical regime, meaning that the boundary layer is expected to be transitional. The study begins with investigation of free two degree-of-freedom simulations of an individual tube, which are performed at low Reynolds number (3,800), where results are compared favorably to experimental results. High Reynolds number (3 × 10⁶) two degree-of-freedom single tube simulations are also demonstrated. This is followed by a comparison between experiment and computation of flow past a stationary tube bank. Finally, in-phase free oscillation of the single row of tubes is simulated. System behavior in terms of oscillation frequency and amplitude, along with qualitative flow characteristics are discussed.