Hydrodynamic Inertia Coefficients for a Tube Surrounded by Rigid Tubes

Abstract

The virtual mass of a long, transversely vibrating tube submerged in a liquid was experimentally determined. The tube was surrounded by rigid tubes in a hexangular array and in square array, at pitch-to-diameter ratios from 1.25 to 1.5. The inertia coefficients observed were considerably larger than for a cylinder in an infinite volume of fluid, but smaller than one would compute assuming an annulus inscribed within the clear space around the vibrating tube. The results show the reduction of natural frequencies in a submerged tube bundle for one particular relative motion of tubes. Experimental results concerning the increase in damping due to the surrounding tubes are briefly indicated.

Flow-Induced Vibration of Circular Cylindrical Structures

“…The self-addedmass coefficient for the central element is of particular interest. Figure 3.5 shows the values of the coefficient as a function of the pitch-to-diameter ratio as well as the experimental mass obtained by Moretti and Lowery (1976).…”

Cross-Flow-Induced-Vibrations in Heat Exchanger Tube Bundles: A Review

“…Figure 13 gives the results showing the variation of m C with pitch-to-diameter ratios . C -values in tube bundles , Moretti et al, 1976.…”

Fluidelastic instabilities in tube bundles exposed to nonuniform crossflow

“…Furthermore, assume that cylinder k is oscillating in a steadystate harmonic motion, i. Various investigators have used this technique to determine fluid coupling in quiescent fluid-- Moretti and Lowery (1976) and Lubin et al (1977) for ideal fluid and Chen et al (1977) for viscous fluid.…”