Competition between Turbulence and Fluid-Elastic Forces in the Response of a Loosely Supported Tube under Cross-Flow. (2017)

• Record Type: Journal Article
• Authors: Borsoi, Laurent; Piteau, Philippe; Delaune, Xavier; Antunes, Jose
• Is Part Of: Procedia engineering. Volume 199(2017)
• Page Start: 1282
• Page End: 1289
• Publication Date: 2017
• Subjects: loosely supported tube -- cross-flow -- turbulence -- fluid-elastic -- non-linear -- impact -- auto-adjustment -- stop with gap -- perturbation -- limit cycle; Engineering -- Congresses; Engineering -- Periodicals; Engineering; Conference proceedings; Periodicals; 620.005
• DOI: 10.1016/j.proeng.2017.09.310
• Languages: English
• ISSNs: 1877-7058

Abstract

Abstract: In some degraded situations of heat-exchangers, tubes may be loosely supported while subjected to intense cross-flow generating both turbulence and fluid-elastic forces, and so have vibro-impacting responses. This paper aims at providing a better understanding of the dynamics of such systems in which the conjunction of stops with gaps, broadband random excitation, and fluid-elastic coupling forces, either stabilizing or destabilizing, produces some rather amazing effects linked to a general capacity for the system to be auto-adjusted by the impacts. It is especially shown, (i) how a non-linear gap-system "escapes from instability" by reinforcing the sequence of impacts, (ii) the almost perfect time-history mirror symmetry between the works of turbulence and fluid-elastic forces in the energy balance; (iii) the dissipative aspect of turbulence in some cases. Moreover the paper deals with the relative weight of turbulence and fluid-elastic forces in the tube response that notably depends on the gap size. For this, turbulence is considered as a perturbation of limit cycles obtained when the fluid-elastic forces are the only acting fluid-forces. The study is based on configurations mainly 1-DOF, like the one that has been experimentally tested, but extrapolations for real tube bundle are evoked in conclusion.