Eventos Anais de eventos
COBEM 2019
25th International Congress of Mechanical Engineering
EXPERIMENTAL MEASUREMENTS OF PRESSURE AND VELOCITY FIELDS AROUND CIRCULAR CYLINDERS ARRANGED IN PAIRS
Submission Author:
José Leandro Cardoso Rivera Vila , DF
Co-Authors:
José Leandro Cardoso Rivera Vila, Pedro Paulo Silva de Almeida, Thiago Gomes, Tiago de Melo, Jhon Goulart
Presenter: José Leandro Cardoso Rivera Vila
doi://10.26678/ABCM.COBEM2019.COB2019-0714
Abstract
In this paper the pressure field and its fluctuation around circular cylinders arranged in pairs will be measured, as well as the wake characteristics behind each cylinder. The experimental investigation is carried out in an aerodynamic channel with turbulence intensity of free stream less than 3%. The pressure and its fluctuation were gathered through a pressure transducer whereas the velocity fields were measured by using single hot-wire probes. Mathematical tools were employed to identify flow patterns in the velocity and pressure time-traces. During the experimental campaign three p/d-ratio were tested, p/d = 1.26, 2.00 and 3.00, for a constant Reynolds number, ReD = 1.78 104, based on the circular cylinder diameter, D, the free stream velocity, U, and the kinematic viscosity of the fluid,. Through the pressure measurements it was identified that the mean average pressure distribution around the cylinders departs from the that one takes place in a single cylinder as the p/d-ratio decreases. As regards the dynamic of the flow two distinguished behaviors were observed: for intermediated p/d-ratio (2 and 3), the Strouhal number was found slighted superior to 0.21, on the other hand, for the lowest p/d-ratio, the pressure spectrum did not present important peaks. Time-frequency tools were also employed to analyze the dynamic behavior of the flow velocity behind the circular cylinders showing a kind of intermittent process in the vortex shedding when the p/d-ratio decreases.
Keywords
Turbulent flow, Two cylinders side-by-side, pressure transducer, bistability, subcritical regime
