Damping of Heat Exchanger Tubes in Liquids: Review and Design Guidelines

This paper addresses the question of damping of multispan heat exchanger tubes with liquids (mostly water) on the shell side. The different energy dissipation mechanisms that contribute to damping are investigated. The available experimental data from the literature and from our own measurements are reviewed and analyzed. Three important energy dissipation mechanisms emerge. These are viscous damping between the tube and liquid, squeeze-film damping in the clearance between the tube, and support and friction damping at the support. Viscous damping only accounts for approximately 25% of the total damping of a typical tube. Thus, about 75% of the damping energy is dissipated at the support. Squeeze-film damping appears to be the most important energy dissipation mechanism. Squeeze-film damping is related to the support width and is inversely proportional to the tube frequency. Damping is formulated in terms of tube and tube-support parameters. Semi-empirical formulations for damping of heat exchanger tubes in liquids are recommended for design purposes.