Lift Force Generation of a Moving Circular Cylinder with a Strip-Plate Set Downstream in Cruciform Arrangement: Flow Field Improving Using Tip Ends

2018 ◽  
Vol 19 (3) ◽  
pp. 606-617
Author(s):  
Withun Hemsuwan ◽  
Kasumi Sakamoto ◽  
Tsutomu Takahashi
Keyword(s):  
Circular Cylinder ◽  
Flow Field ◽  
Lift Force ◽  
Force Generation ◽  
Strip Plate

A theory of circulation control by slot-blowing, applied to a circular cylinder

1968 ◽  
Vol 33 (3) ◽  
pp. 495-514 ◽  
Author(s):  
J. Dunham
Keyword(s):  
Boundary Layer ◽  
Circular Cylinder ◽  
Flow Field ◽  
Lift Force ◽  
Air Flow ◽  
Inviscid Flow ◽  
Boundary Layer Theory ◽  
Experimental Results ◽  
Circulation Control ◽  
Narrow Slot

Lift can be generated on a circular cylinder with its axis normal to an air flow by blowing a sheet of air tangentially round the upper surface from a narrow slot or slots. This lift force may be estimated by matching the external inviscid flow field with separation points calculated by Spalding's unified boundary-layer theory. The theory reproduces experimental results reasonably well, except in certain special conditions fully discussed.

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.

Development of a flow field structure in the vicinity of a circular cylinder in the presence of a laminar-turbulent transition

2000 ◽  
Vol 38 (5) ◽  
pp. 732-741
Author(s):  
V. A. Bashkin ◽  
I. V. Egorov ◽  
M. V. Egorova ◽  
D. V. Ivanov
Keyword(s):  
Circular Cylinder ◽  
Flow Field ◽  
Field Structure ◽  
Turbulent Transition ◽  
Laminar Turbulent Transition

scholarly journals The drag-adjoint field of a circular cylinder wake at Reynolds numbers 20, 100 and 500

2013 ◽  
Vol 730 ◽  
pp. 145-161 ◽  
Author(s):  
Qiqi Wang ◽  
Jun-Hui Gao
Keyword(s):  
Circular Cylinder ◽  
Flow Field ◽  
Unsteady Flow ◽  
Numerical Solutions ◽  
Reynolds Numbers ◽  
Adjoint Equations ◽  
Cylinder Wake ◽  
Near Wake ◽  
Navier Stokes Equation ◽  
D 20

AbstractThis paper analyses the adjoint solution of the Navier–Stokes equation. We focus on flow across a circular cylinder at three Reynolds numbers, ${\mathit{Re}}_{D} = 20, 100$ and $500$. The quantity of interest in the adjoint formulation is the drag on the cylinder. We use classical fluid mechanics approaches to analyse the adjoint solution, which is a vector field similar to a flow field. Production and dissipation of kinetic energy of the adjoint field is discussed. We also derive the evolution of circulation of the adjoint field along a closed material contour. These analytical results are used to explain three numerical solutions of the adjoint equations presented in this paper. The adjoint solution at ${\mathit{Re}}_{D} = 20$, a viscous steady state flow, exhibits a downstream suction and an upstream jet, the opposite of the expected behaviour of a flow field. The adjoint solution at ${\mathit{Re}}_{D} = 100$, a periodic two-dimensional unsteady flow, exhibits periodic, bean-shaped circulation in the near-wake region. The adjoint solution at ${\mathit{Re}}_{D} = 500$, a turbulent three-dimensional unsteady flow, has complex dynamics created by the shear layer in the near wake. The magnitude of the adjoint solution increases exponentially at the rate of the first Lyapunov exponent. These numerical results correlate well with the theoretical analysis presented in this paper.

scholarly journals Flow Field Formed Around a Horizontally Submerged Circular Cylinder in the Vicinity of Channel Bed.

1993 ◽  
Vol 13 (50) ◽  
pp. 183-194
Author(s):  
Minoru KUBOTA ◽  
Masahiko MAEJIMA ◽  
Takanori KUTSUMI
Keyword(s):  
Circular Cylinder ◽  
Flow Field

scholarly journals Experimental Studies on Fluctuating Lift Force on a Single Circular Cylinder at High Reynolds Numbers

1988 ◽  
Vol 1988 (37) ◽  
pp. 73-82
Author(s):  
K. FUJITA ◽  
Y. IKEGAMI ◽  
K. KOBAYASHI ◽  
M. OHASHI
Keyword(s):  
Circular Cylinder ◽  
Lift Force ◽  
Experimental Studies ◽  
Reynolds Numbers ◽  
High Reynolds Numbers ◽  
High Reynolds
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