Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
Analysis of the switching flow after two cylinders side-by-side submitted to a high turbulence impinging flow
Submission Author:
Ana Ost , RS , Brazil
Co-Authors:
Sergio Viçosa Möller, Ana Ost
Presenter: Ana Ost
doi://10.26678/ABCM.COBEM2017.COB17-0544
Abstract
Bistability describes a phenomenon which, under the same conditions, presents distinct stable behaviors, where two different flow modes are present and remain in a stable configuration, during a certain period of time until a second flow mode is assumed. An experimental study, about the influence of the turbulence intensity on a bistable flow, were the flow through two cylinders side-by-side is studied in an aerodynamic channel with two turbulence intensities, lower than 1%, and about 7.5%, was performed. Usually, this phenomenon is investigated using Wavelets and Fourier Spectral Analysis. This work suggests the use of Hilbert-Huang Transform as a method that enables the analysis of non-stationary and non-linear turbulent signals. The experiment was performed with two rigid cylinders with an arrangement of pitch-to-diameter ratio (p/d) of 1.26 The hot wire anemometry technique was used as experimental technique. The results show that the Hilbert-Huang Transform can improve significantly the analysis of turbulent data, revealing the main characteristics of signal by obtaining the instantaneous frequency of it.
Keywords
Turbulent flow, bistability, Turbulence intensity, Hilbert-Huang Transform.
