Video of axial flow-induced vibration (FIV) simulations at different axial position using RSM LRR and EVM k-ω SST models

Background:
This simulation validates a numerical methodology for predicting axial flow-induced vibration (FIV) by comparing results to experimental data for a blunt-end cantilever rod under axial flow, as detailed in Muhamad Pauzi et al. (2024). The rod dimensions and properties are representative of fuel rods in pressurised water reactors (PWRs). The study shows that both URANS models (described below) achieve good agreement with experimental measurements of root-mean-square (RMS) amplitudes and first mode frequency of vibrations. These findings are crucial for mitigating fretting wear in loosely supported fuel rods, reducing fuel failure and enhancing the reliability of nuclear power plants.

Videos:
The included videos illustrate the changes in both flow contours and structural displacement during self-excited FIV at an annulus Reynolds number of 35,100. These contour plots are dimensionless and present velocity, pressure, turbulent kinetic energy, and vorticity at various axial positions.

1. Video 1: This video visualises the onset of two-way fluid-structure interaction (FSI) coupling from 3 to 8 seconds of simulation time. The data are visualised at every 0.01 seconds, corresponding to 100 time steps (Δt = 0.0001 s).
2. Video 2: This video highlights a representative time window from 4.00 to 4.05 seconds, showcasing contour variations at each time step (Δt = 0.0001 s).

Simulation Setup:

• Fluid Model:
• • High-Reynolds number URANS models:
  • • (Top) Reynolds Stress Model (RSM), LRR model by Launder et al. (1975)
    • (Bottom) Eddy Viscosity Model (EVM), k-ω SST model by Menter (1994)
• Solid Model:
• • Linear elastic model
• Fluid-Structure Interaction (FSI) Coupling:
• • Two-way FSI using the IQN-ILS coupling algorithm by Degroote et al. (2009).

Software: The simulation utilised Foam-extend-4.0, solids4Foam for FSI modelling, Paraview for visualisation, and Canva for presentation design.

References:

• Muhamad Pauzi, A. et al. (2024) ‘Application of URANS Simulation and Experimental Validation of Axial Flow-Induced Vibrations on a Blunt-End Cantilever Rod for Nuclear Applications’, Arabian Journal for Science and Engineering. Available at: https://doi.org/10.1007/s13369-024-09505-5
• Launder, B. E., Reece, G. J., & Rodi, W. (1975). Progress in the development of a Reynolds-stress turbulence closure. Journal of Fluid Mechanics, 68(3), 537–566. https://doi.org/10.1017/S0022112075001814
• Menter, F. R. (1994). Two-equation eddy-viscosity turbulence models for engineering applications. AIAA Journal, 32(8), 1598–1605. https://doi.org/10.2514/3.12149
• Degroote, J., Bathe, K. J., & Vierendeels, J. (2009). Performance of a new partitioned procedure versus a monolithic procedure in fluid-structure interaction. Computers and Structures, 87(11–12), 793–801. https://doi.org/10.1016/j.compstruc.2008.11.013