Passive Control of the Vortex Shedding Noise of a Cylinder at Low Reynolds Numbers Using Flexible Flaps

2017 ◽  
Author(s):  
Thomas F. Geyer ◽  
Laura Kamps ◽  
Ennes Sarradj ◽  
Christoph Brücker
Keyword(s):  
Vortex Shedding ◽  
Passive Control ◽  
Reynolds Numbers ◽  
Low Reynolds Numbers ◽  
Low Reynolds ◽  
Vortex Shedding Noise

Suppression of vortex shedding behind a circular cylinder by another control cylinder at low Reynolds numbers

2007 ◽  
Vol 573 ◽  
pp. 171-190 ◽  
Author(s):  
A. DIPANKAR ◽  
T. K. SENGUPTA ◽  
S. B. TALLA
Keyword(s):  
Vortex Shedding ◽  
Physical Mechanism ◽  
Grid Method ◽  
Reynolds Numbers ◽  
Accurate Solution ◽  
Navier Stokes ◽  
Navier Stokes Equation ◽  
Low Reynolds Numbers ◽  
Low Reynolds ◽  
Control Cylinder

Vortex shedding behind a cylinder can be controlled by placing another small cylinder behind it, at low Reynolds numbers. This has been demonstrated experimentally by Strykowski & Sreenivasan (J. Fluid Mech. vol. 218, 1990, p. 74). These authors also provided preliminary numerical results, modelling the control cylinder by the innovative application of boundary conditions on some selective nodes. There are no other computational and theoretical studies that have explored the physical mechanism. In the present work, using an over-set grid method, we report and verify numerically the experimental results for flow past a pair of cylinders. Apart from providing an accurate solution of the Navier–Stokes equation, we also employ an energy-based receptivity analysis method to discuss some aspects of the physical mechanism behind vortex shedding and its control. These results are compared with the flow picture developed using a dynamical system approach based on the proper orthogonal decomposition (POD) technique.

Control of vortex shedding by thermal effect at low Reynolds numbers

2000 ◽  
Vol 21 (4) ◽  
pp. 227-237 ◽  
Author(s):  
J.-C. Lecordier ◽  
L.W.B. Browne ◽  
S. Le Masson ◽  
F. Dumouchel ◽  
P. Paranthoën
Keyword(s):  
Thermal Effect ◽  
Vortex Shedding ◽  
Reynolds Numbers ◽  
Low Reynolds Numbers ◽  
Low Reynolds

Feedback control of vortex shedding at low Reynolds numbers

1993 ◽  
Vol 248 ◽  
pp. 267-296 ◽  
Author(s):  
Kimon Roussopoulos
Keyword(s):  
Feedback Control ◽  
Vortex Shedding ◽  
Single Channel ◽  
Water Channel ◽  
Open Water ◽  
Reynolds Numbers ◽  
Circular Cylinders ◽  
Low Reynolds Numbers ◽  
Wake Instability ◽  
Low Reynolds

This paper describes experiments undertaken to study in detail the control of vortex shedding from circular cylinders at low Reynolds numbers by using feedback to stabilize the wake instability. Experiments have been performed both in a wind tunnel and in an open water channel with flow visualization. It has been found that feedback control is able to delay the onset of the wake instability, rendering the wake stable at Reynolds numbers about 20% higher than otherwise. At higher flow rates, however, it was not possible to use single-channel feedback to stabilize the wake - although, deceptively, it was possible to reduce the unsteadiness recorded by a near-wake sensor. When control is applied to a long span only the region near the control sensor is controlled. The results presented in this paper generally support the analytical results of other researchers.

Sign in / Sign up

Export Citation Format

Share Document