Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
INVESTIGATION OF THE HIGH ENERGY MODE BRANCH IN FLEXIBLE CYLINDERS VIV: A NOVEL RECURSIVE EXPERIMENTAL ANALYSIS METHODOLOGY
Submission Author:
Wagner Antonio Defensor Filho , SP
Co-Authors:
CELSO Pupo Pesce, Guilherme Franzini, Wagner Antonio Defensor Filho
Presenter: Wagner Antonio Defensor Filho
doi://10.26678/ABCM.COBEM2017.COB17-0946
Abstract
An experimental investigation was conducted at a circulating water channel on the “high speed mode response branch”, firstly revealed in the works by Fujarra et al 2001, from experiments with cantilevered flexible cylinders with orthotropic bending stiffnesses. Such a branch, herein called ‘high energy mode branch’ HEMB, is characterized by oscillation amplitudes of order of one diameter, in a range of reduced velocities much beyond the usual VIV lock-in peak. The present campaign systematically addresses the effect of the natural frequency ratio, fx1/fy1, on the HEMB. A response branch chart obtained as a function of reduced velocity and parameterized according to the frequency ratio is the ultimate focus of this investigation. The present paper describes the experimental methodology, including a novel experimental analysis procedure based on a recursive application of the Hilbert-Huang Transform. Preliminary experimental results are shown.
Keywords
vortex induced vibrations, High Energy Mode Branch, Hilbert-Huang Transform., Empirical Mode Decomposition, experimental analysis methodology, flexible cylinders, fluid-structure interactions
