Flow-induced vibration (FIV) is a critical concern in various engineering applications, including piping systems, valves, and nuclear fuel bundles, where excessive vibration can lead to structural damage, fatigue failure, and flow instabilities. This presentation provides an overview of FIV mechanisms in practical engineering systems, with a particular focus on the vibration response of tube arrays subjected to cross-flow. Tube arrays are commonly found in heat exchangers and steam generators, where fluid-structure interactions can result in complex vibratory behaviors, including vortex shedding, turbulence-induced excitation, and fluidelastic instability.