MODELLING THE UNSTEADY AXIAL FORCES ON A FINITE-LENGTH CIRCULAR CYLINDER IN CROSS-FLOW

2002 ◽  
Vol 16 (5) ◽  
pp. 667-683 ◽  
Author(s):  
D.E. CAPONE ◽  
G.C. LAUCHLE
Keyword(s):  
Circular Cylinder ◽  
Finite Length ◽  
Cross Flow ◽  
Axial Forces

scholarly journals Dynamics of the Tip Vortices in the Wake Behind a Circular Cylinder of Finite Length

2020 ◽  
Vol 328 ◽  
pp. 05008
Author(s):  
Václav Uruba ◽  
Pavel Procházka
Keyword(s):  
Circular Cylinder ◽  
Finite Length ◽  
Ground Plane ◽  
Cross Flow ◽  
Cylinder Axis ◽  
Thin Boundary Layer ◽  
Time Resolved ◽  
Vortical Structures ◽  
Tip Vortices ◽  
Piv Technique

The dynamics of the tip vortices in the wake behind a wall-mounted finite-length circular cylinder of the aspect ratio 2 was studied experimentally using time resolved stereo PIV technique. The cylinder was mounted normal to a ground plane and it was subjected to a cross-flow with thin boundary layer developed on the wall, the Reynolds number based on inflow velocity and cylinder diameter was 9.7 thousands. The dynamics of tip vortices were analysed using the POD method applied to the plane perpendicular to the flow close to the cylinder. Besides the decaying power spectrum, slower that the Kolmogorov-type one, the two distinct frequencies were detected on Strouhal numbers 0.09 and 0.15. These frequencies could be linked to the vortical structures dynamics in the wake. The frequency Sh = 0.15 corresponds to predominantly spanwise vortices dynamics with anti-symmetrical patterns with respect to the cylinder axis, while the frequency Sh = 0.09 corresponds to mainly streamwise vortical structures dynamics with symmetrical patterns respectively. Thus, the von Kármán vortex street was detected on Strouhal frequency 0.15.

TRANSONIC CROSS FLOW (M∞ = 0.8) OVER A CIRCULAR CYLINDER AT HIGH REYNOLDS NUMBERS

2012 ◽  
Vol 43 (5) ◽  
pp. 589-613
Author(s):  
Vyacheslav Antonovich Bashkin ◽  
Ivan Vladimirovich Egorov ◽  
Ivan Valeryevich Ezhov ◽  
Sergey Vladimirovich Utyuzhnikov
Keyword(s):  
Circular Cylinder ◽  
Cross Flow ◽  
Reynolds Numbers ◽  
High Reynolds Numbers ◽  
High Reynolds

scholarly journals Aerodynamics of a Circular Cylinder of Finite Length

1988 ◽  
Vol 1988 (36) ◽  
pp. 27-43
Author(s):  
Yasushi UEMATSU ◽  
Motohiko YAMADA ◽  
Kaoru ISHII
Keyword(s):  
Circular Cylinder ◽  
Finite Length

The Numerical Simulation of Two-Degrees-of-Freedom Vortex-Induced Vibrations of Circular Cylinder with High Mass-Ratio

2013 ◽  
Vol 284-287 ◽  
pp. 557-561
Author(s):  
Jie Li Fan ◽  
Wei Ping Huang
Keyword(s):  
Circular Cylinder ◽  
Drag Force ◽  
Frequency Ratio ◽  
Lift Force ◽  
Degrees Of Freedom ◽  
Cross Flow ◽  
High Mass ◽  
Mass Ratio ◽  
Main Frequency ◽  
Line Amplitude

The two-degrees-of-freedom VIV of the circular cylinder with high mass-ratio is numerically simulated with the software ANSYS/CFX. The VIV characteristic is analyzed in the different conditions (Ur=3, 5, 6, 8, 10). When Ur is 5, 6, 8 and 10, the conclusion which is different from the cylinder with low mass-ratio can be obtained. When Ur is 3, the frequency of in-line VIV is twice of that of cross-flow VIV which is equal to the frequency ratio between drag force and lift force, and the in-line amplitude is much smaller than the cross-flow amplitude. The motion trace is the crescent. When Ur is 5 and 6, the frequency ratio between the drag force and lift force is still 2, but the main frequency of in-line VIV is mainly the same as that of cross-flow VIV and the secondary frequency of in-line VIV is equal to the frequency of the drag force. The in-line amplitude is still very small compared with the cross-flow amplitude. When Ur is up to 8 and 10, the frequency of in-line VIV is the same as the main frequency of cross-flow VIV which is close to the inherent frequency of the cylinder and is different from the frequency of drag force or lift force. But the secondary frequency of cross-flow VIV is equal to the frequency of the lift force. The amplitude ratio of the VIV between in-line and cross-flow direction is about 0.5. When Ur is 5, 6, 8 and 10, the motion trace is mainly the oval.

The Circular Cylinder With a Band of Uniform Pressure on a Finite Length of the Surface

1941 ◽  
Vol 8 (3) ◽  
pp. A97-A104 ◽  
Author(s):  
M. V. Barton
Keyword(s):  
Circular Cylinder ◽  
Finite Length ◽  
Infinite Series ◽  
Fundamental Problem ◽  
The Other ◽  
Complete Picture ◽  
Uniform Pressure ◽  
Uniform Tension ◽  
Special Cases ◽  
Stress And Deformation

Abstract The solution to the fundamental problem of a cylinder with a uniform pressure over one half its length and a uniform tension on the other half is found by using the Papcovitch-Neuber solution to the general equations. In this paper, the results, given analytically in terms of infinite-series expressions, are exhibited as curves giving a complete picture of the stress and deformation. The case of a cylinder with a band of uniform pressure of any length, with the exception of very small ones, is then solved by the method of superposition. The stresses and displacements are evaluated for the special cases of a cylinder with a uniform pressure load of 1 diam and 1/2 diam in length. The problem of a cylinder heated over one half its length is solved by the same means.

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