Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
EXPERIMENTAL ANALYSIS OF TURBULENT TRANSVERSAL FLOW ON TWO FIXED PARALLEL CYLINDERS WITH OSCILLATORY AND ROTATIONAL FREEDOM
Submission Author:
Dolir Varela , RS
Co-Authors:
Dolir Varela, Roberta Fatima Neumeister, Gustavo Dias, Alexandre Vagtinski de Paula, Sergio Viçosa Möller
Presenter: Sergio Viçosa Möller
doi://10.26678/ABCM.COBEM2017.COB17-0956
Abstract
This paper presents an experimental study of the bistability phenomenon that occurs in the simplified geometry of two tubes arranged side by side submitted to a turbulent cross flow. In the analysis we consider the condition of fixed tubes and with a degree of freedom (rotational), submitted to different numbers of Reynolds. The experimental technique consists in the measurement of flow rate fluctuations through the aerodynamic channel hot wire anemometry and the evaluation of the stresses of the flow on the tubes with the use of a load cell. The data obtained from the measurement in the channel are treated with the use of statistical, spectral and wavelet tools. In the experimental results we observe the presence of bistability and note the non-simultaneous behavior of the phenomenon along the cylinders. The asymmetric formation of the wakes is also studied and attributed to the interaction between the vortices from wakes behind the cylinders, since, initially, the wake detachments is symmetrical. In the evaluation of the forces by means of the extensiometry technique, the steps of conditioning and acquisition of the signal were elaborated and the results of mechanical deformation presented similarity with the phenomenon observed in the experimental anemometry. For a Reynolds number of 27635 a force of 26.1 mN was found with a torque developed in the load cell of 84.95 Nmm.
Keywords
Bistable Flow, Hot wire anemometr, experimental analysis, Turbulence, Load cell
