Study of fluidelastic instability in the streamwise and transverse directions through tube array under two-phase flow conditions using pressure effects

• DOI: 10.1016/j.net.2024.08.017
• Publication Date: 2024-08-12T21:58:43Z
• Authors: Sijiu Qi; Wei Tan; Ke Zhang; Yuancen Wang; Wenjing Lin; Peize Han; Guorui Zhu
• Keywords: Normal triangular arrangement; TK9001-9401; Pressure; Fluidelastic instability; Nuclear engineering. Atomic power; Flow-induced vibrations

The fluidelastic instability (FEI) in heat exchanger tubes has been of widespread concern due to its tendency cause damage the tubes. Generally, FEI transverse direction tube occurs earlier than streamwise direction, and intrinsic frequency as well way distribution have a great influence. mechanisms involved inducing need be further investigated. We set up an air-water two-phase flow water tunnel test system adopt normal triangular arrangement plate with pitch-to-diameter ratio 1.41 conduct experiments. It was ensured that could occur experimental range, by varying flexible tube. phenomenon investigated single array cluster seven (the central cluster). Comparative analysis conducted between results two configurations. experiments concurrent directions, pressure exerted on Additionally, "transitional" state observed under strongly coupled vibration explored. findings indicated intensified coupling bundles, leading more complex field around bundle perimeter, consequently exacerbating vibration. Furthermore, state, enhanced stability manifested. primarily controlled stiffness mechanism; did not exhibit while did. This paper recommends constant (K) value 3.4 for Connors formula configuration 1.41, thereby providing empirical theoretical support bundles.