Development of a bluff body wake under the combined influence of curvature and pressure gradient

1995 ◽  
Vol 18 (5) ◽  
pp. 311-318 ◽  
Author(s):  
E. G. Tulapurkara ◽  
V. Ramjee ◽  
Jacob George
Keyword(s):  
Pressure Gradient ◽  
Bluff Body ◽  
Bluff Body Wake

scholarly journals Pressure gradient tailoring effects on the mechanisms of bluff-body flame extinction

2020 ◽  
Vol 215 ◽  
pp. 224-237 ◽  
Author(s):  
Anthony J. Morales ◽  
Jonathan Reyes ◽  
Peter H. Joo ◽  
Isaac Boxx ◽  
Kareem A. Ahmed
Keyword(s):  
Pressure Gradient ◽  
Bluff Body ◽  
Flame Extinction

Open Loop Transient Forcing of an Axisymmetric Bluff Body Wake

2008 ◽  
Author(s):  
Stefan Siegel ◽  
Jürgen Seidel ◽  
Kelly Cohen ◽  
Selin Aradag ◽  
Thomas McLaughlin
Keyword(s):  
Bluff Body ◽  
Open Loop ◽  
Transient Forcing ◽  
Bluff Body Wake

Control of vortex shedding in an axisymmetric bluff body wake

2000 ◽  
Vol 19 (5) ◽  
pp. 789-812 ◽  
Author(s):  
Ansgar Weickgenannt ◽  
Peter A. Monkewitz
Keyword(s):  
Vortex Shedding ◽  
Bluff Body ◽  
Bluff Body Wake

scholarly journals Stochastic modelling and feedback control of bistability in a turbulent bluff body wake

2016 ◽  
Vol 802 ◽  
pp. 726-749 ◽  
Author(s):  
R. D. Brackston ◽  
J. M. García de la Cruz ◽  
A. Wynn ◽  
G. Rigas ◽  
J. F. Morrison
Keyword(s):  
Reynolds Number ◽  
Feedback Control ◽  
Symmetry Breaking ◽  
Large Scale ◽  
Bluff Body ◽  
Three Dimensional ◽  
Power Saving ◽  
Stochastic Modelling ◽  
Bluff Body Wake ◽  
Modelling Approach

A specific feature of three-dimensional bluff body wakes, flow bistability, is a subject of particular recent interest. This feature consists of a random flipping of the wake between two asymmetric configurations and is believed to contribute to the pressure drag of many bluff bodies. In this study we apply the modelling approach recently suggested for axisymmetric bodies by Rigaset al.(J. Fluid Mech., vol. 778, 2015, R2) to the reflectional symmetry-breaking modes of a rectilinear bluff body wake. We demonstrate the validity of the model and its Reynolds number independence through time-resolved base pressure measurements of the natural wake. Further, oscillating flaps are used to investigate the dynamics and time scales of the instability associated with the flipping process, demonstrating that they are largely independent of Reynolds number. The modelling approach is then used to design a feedback controller that uses the flaps to suppress the symmetry-breaking modes. The controller is successful, leading to a suppression of the bistability of the wake, with concomitant reductions in both lateral and streamwise forces. Importantly, the controller is found to be efficient, the actuator requiring only 24 % of the aerodynamic power saving. The controller therefore provides a key demonstration of efficient feedback control used to reduce the drag of a high-Reynolds-number three-dimensional bluff body. Furthermore, the results suggest that suppression of large-scale structures is a fundamentally efficient approach for bluff body drag reduction.

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