Argonne National Laboratory. Energy Technology Division.
Abstract
A mathematical model for fluid damping controlled instability of tubes presented in this paper is based on the unsteady flow theory. Motion dependent fluid forces are measured in a water channel. From the measured fluid forces, fluid stiffness and fluid damping coefficients, are calculated as a function of reduced flow velocity, oscillation amplitude, and Reynolds number. Once these coefficients are known, the mathematical model can be applied to predict structural instability due to fluid damping. Many cases are considered: single tube, twin tubes, tube row, triangular array, and square arrays. The results show the instability regions based on the fluid damping coefficients and provide the answers to a series of questions on fluid elastic instability of tube arrays in crossflow
