Role of Karman vortex on bluff body aerodynamics

2008 ◽  
Vol 2008 (116) ◽  
pp. 182-191 ◽  
Author(s):  
Masaru MATSUMOTO
Keyword(s):  
Bluff Body ◽  
Bluff Body Aerodynamics ◽  
Karman Vortex

What is the Role of the Stagnation Region in Karman Vortex Shedding?

2011 ◽  
Vol 18 (3) ◽  
pp. 361-370 ◽  
Author(s):  
Grzegorz Pankanin
Keyword(s):  
Vortex Shedding ◽  
Bluff Body ◽  
Flow Visualisation ◽  
Information Channel ◽  
Hot Wire ◽  
Stagnation Region ◽  
Karman Vortex ◽  
Experimental Findings ◽  
The Relationship

What is the Role of the Stagnation Region in Karman Vortex Shedding?This paper is devoted to the problem of the appearance of a stagnation region during Karman vortex shedding. This particular phenomenon has been addressed by G. Birkhoff in his model of vortices generation. Experimental results obtained by various research methods confirm the existence of a stagnation region. The properties of this stagnation region have been described based on experimental findings involving flow visualisation and hot-wire anemometry. Special attention has been paid to the relationship between the existence of a slit in the bluff body and the size of the stagnation region. The slit takes over the role of the stagnation region as an information channel for generating vortices.

Karman Vortex Effect on the Aerodynamic Forces to Rectangular Cylinders

2006 ◽  
Author(s):  
M. Matsumoto ◽  
T. Yagi ◽  
J. H. Lee ◽  
K. Hori ◽  
Y. Kawashima
Keyword(s):  
Bluff Body ◽  
Splitter Plate ◽  
Aerodynamic Forces ◽  
Vortex Effect ◽  
Side Ratio ◽  
Back Ground ◽  
Karman Vortex ◽  
Bluff Body Flow ◽  
Rectangular Cylinders

Standing on the back-ground associated with the complicated bluff body aerodynamics affected by Karman vortex, the fundamental wind tunnel tests have been carried out to clarify the role of Karman vortex on the aerostatic forces and the aerodynamic forces of 2D rectangular cylinders with various side ratios in the range from B/D=0.3 to B/D=15. For mitigation of Karman vortex, a splitter plate with suitable size was installed in a wake center. As far as stationary drag force, the sharp peak in CD-B/D diagrams, completely disappear by a splitter plate installation. On the other hand, the value of dCL/dα is significantly sensitive to the Karman vortex, in particular, even its sign changes in the range from B/D=0.6 to B/D=0.7 and B/D=3.0 to B/D=4.0, which means the significant role of the Karman vortex on the galloping instability, from the point of quasi-steady theory. Furthermore, the flutter derivatives are also drastically affected by Karman vortex in the rather wide reduced velocity far from the Karman vortex resonant reduced velocity. In summary, it would be emphasized that the substantial bluff body flow might be characterized by the side ratio of cylinders, and these fundamental flows should be significantly or slightly affected by Karman vortex depending on their side ratios of cylinders.

Basic bluff-body aerodynamics

2020 ◽  
pp. 117-154
Author(s):  
John D. Holmes ◽  
Seifu A. Bekele
Keyword(s):  
Bluff Body ◽  
Bluff Body Aerodynamics
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