Operational Modal Analysis of a Triangular-Pitch Tube Bundle Subjected to Two-Phase Cross-Flow - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Journal of Pressure Vessel Technology Année : 2018

Operational Modal Analysis of a Triangular-Pitch Tube Bundle Subjected to Two-Phase Cross-Flow

(1)
1
Enrico Deri
  • Fonction : Auteur
  • PersonId : 1032582

Résumé

Flow-induced vibrations of tubes in two-phase heat exchangers are a concern for the nuclear industry. EDF has developed a numerical tool, which allows one to evaluate safety margins and thereafter to optimize the exchanger maintenance policy. The software is based on a semi analytical model of fluid-dynamic forces and dimensionless fluid force coefficients which need to be evaluated by experiment. A test rig was operated with the aim of assessing parallel triangular tube arrangement submitted to a two-phase vertical cross-flow: a kernel of nine flexible tubes is set in the middle of a rigid bundle. These tubes vibrate as solid bodies (in translation) both in the lift and drag directions in order to represent the so-called in-plane and out-of-plane vibrations. This paper outlines the experimental results and some detailed physical analysis of some selected points of the experiment series: the response modes are identified by means of operational modal analysis (i.e. under unmeasured flow excitation) and presented in terms of frequency , damping and mode shapes. Among all the modes theoretically possible in the bundle, it was found that some of them have a higher response depending on the flow velocity and the void fraction. Mode shapes allow to argue if lock-in is present and to clarify the role of lift and drag forces close to the fluidelastic instability.
Fichier non déposé

Dates et versions

hal-01804695 , version 1 (01-06-2018)

Identifiants

Citer

Enrico Deri. Operational Modal Analysis of a Triangular-Pitch Tube Bundle Subjected to Two-Phase Cross-Flow. Journal of Pressure Vessel Technology, 2018, 140 (3), ⟨10.1115/1.4038725⟩. ⟨hal-01804695⟩

Collections

EDF
40 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook Twitter LinkedIn More