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COBEM 2019
25th International Congress of Mechanical Engineering
ANALYSIS OF THE WAKE OF TWO PARALLEL CIRCULAR CYLINDERS AT SEVERAL ANGULAR POSITIONS TO THE FLOW
Submission Author:
Patrick Habowski , RS , Brazil
Co-Authors:
Patrick Habowski, Alexandre Vagtinski de Paula, Sergio Viçosa Möller
Presenter: Patrick Habowski
doi://10.26678/ABCM.COBEM2019.COB2019-1304
Abstract
An experimental study performed in an air channel using hot wire anemometers and a flow observation in a hydrodynamic channel is presented, for a configuration of two rigid cylinders with different angular positions to the flow. The main objective is to analyze the effects of flow incidence angles on the bistability, employing two different schemes of positioning of the hot wire anemometers. Bistability is a phenomenon which presents two distinct behaviors for the wake under the same conditions to the flow, occurring in some specific configurations, like two parallel cylinders placed side-by-side. In the first scheme analyzed, the anemometers had a fixed distance from the center of rotation axis and in the second one was used a movable table to modify the position every time the angle was changed. The discrete wavelets transform was applied in order to reconstruct the velocity signals. The results showed the presence of bistability only for side-by-side configuration, being clearer its observation with second measuring scheme. Through the flow visualization was possible to see the flow mode changes for side-by-side configuration, and for the other angles, the presence of a narrow and a wide wake were observed, but without flow mode changes, in accordance with the results in the air flow channel.
Keywords
Turbulent flow, Hot Wires, Bistability Flow Phenomenon, wavelets, Flow Visualization
