SIMULATION OF TUBE BUNDLE VIBRATIONS INDUCED BY CROSS-FLOW

A two-dimensional simulation model for flow-induced vibrations of tube bundles subjected to single-phase cross-flow is applied on six differ ent bundles at realistic Reynolds numbers. The calculation scheme solv es the unsteady Navier-Stokes equations, including turbulence modellin g. Fluid forces, tube acceleration, tube velocity and tube displacemen ts are computed after each time step due to the current flow field. Th e bundles are square and 30 degrees-arrangements, with pitch-to-diamet er ratios of 1.2 up to 2.4. The point of resonance or instability is d etermined by increasing the approach velocity step by step. The result s are analysed and compared with experimental data and with design cri teria proposed in the literature. (C) 1997 Academic Press Limited.