Analysis on streamwise fluidelastic instability of rotated triangular tube arrays subjected to two-phase flow

摘要

Fluidelastic instability of a tube array in a steam generator is a key factor for the security of a nuclear power plant. Several experimental and theoretical analyses were carried out to investigate the out-plane fluidelastic instability of a tube array subjected to two-phase flow. Recently, streamwise fluidelastic instability in the steam generator has been observed in an operating nuclear power plant. To illustrate the streamwise fluidelastic instability of a rotated triangular array in two-phase flow, a mathematical model of a cluster of seven flexible tubes was proposed and a computational program was written in this paper. A series of experiments were conducted to obtain the critical velocity of the tube array within void fraction ranging from 0% to 80%. By comparing the experimental and numerical results, the mathematical model and the computational program was verified. Base on the model, the streamwise fluidelastic instability of six kinds of flexible tube array configurations in two-phase flow was further investigated. The results demonstrate that streamwise fluidelastic instability of a tube array in two-phase flow may be influenced by the immediate neighboring tubes. (C) 2019 Elsevier Ltd. All rights reserved.