Session: FSI-02-03 Vortex Shedding

Paper Number: 121986

121986 - Wake Flow Study on Two Tandem Circular Cylinders: Spacing Ratio and Reynolds Number Effects 

Circular cylinders positioned in tandem configuration are commonly observed in engineering applications: bridge pillars, wind energy towers, transmission lines, and buildings are some examples. The downstream cylinder in a tandem configuration is submitted to the wake flow effects from the upstream cylinder. The effects observed in the downstream cylinder vary depending on the distance between both cylinders and the flow velocity. In critical cases, the downstream cylinder may present uncontrolled vibrations if the vortex shedding frequency matches the natural frequency of the system. This article aims to investigate several L/D spacing ratios and Reynolds numbers, where L is the longitudinal distance between the cylinders with diameter D.
Two main experiments were conducted in this study in two different wind tunnels. In the first one, two accelerometers type ADXL335 were used together with two hot-wire anemometers model DANTEC 55P11 to monitor the lateral acceleration and the wake flow velocity. In the second experiment, the PIV technique was employed to observe the vortex shedding pattern.
Small (2.75<L/D<4.5) and large (7.5<L/D<12) spacing ratios with four different Reynolds numbers were tested. Both wind tunnels are made mainly of wood panels with an acrylic glass section to observe the experiment. The wind tunnels have different dimensions, however, the parameters of the experiment remained the same in both wind tunnels. The data was post-processed using MATLAB software employing discrete wavelet transform (DWT) in the lateral acceleration and wake flow velocity results.
Partial results presented a strong dependence on the spacing ratio and the lateral oscillation movement. The Reynolds number also modified the amplitude and frequency of the oscillations. Expected results regard the comprehension of the visualized wakes and their consequences in the downstream cylinder.
 

Presenting Author: Patrick Batista Habowski Universidade Federal do Rio Grande do Sul

Presenting Author Biography: Ph.D. student at Universidade Federal do Rio Grande do Sul, researching new technologies for wind energy generation, study of the fluid-structure interaction, vibration and vortex shedding control on cylindrical surfaces. Master in mechanical engineering in the Transport Phenomena area (Universidade Federal do Rio Grande do Sul, 2020), where the author studied the behaviour of the vortex wake through cylinders, contributing to the state of the art for the phenomenon of bistability and its usage in wind energy generation. Graduated in Mechanical Engineering (Universidade Federal de Santa Maria, 2017), being the exclusive student to obtain the academic award. In this opportunity, the author worked especially in the thermal area, developing projects in internal combustion engines employing computer simulations and experiments. Experience with fluid dynamic experiments, hot wire anemometry, flow visualization, wavelet transform, design of mechanical parts, fluid dynamics simulations, and internal combustion engines.

Authors:

Patrick Batista Habowski Universidade Federal do Rio Grande do Sul
Adriane Prisco Petry Universidade Federal do Rio Grande do Sul
Sergio Viçosa Möller Universidade Federal do Rio Grande do Sul
Atef Mohany Ontario Tech University