Flow Characteristics of a Circular Cylinder behind an Impinging Airfoil Near Wake with Different Lateral Spacing

2021 ◽  
Vol 14 (3) ◽  
pp. 281-288
Author(s):  
Renjing Cao ◽  
Zhouming Liu
Keyword(s):  
Circular Cylinder ◽  
Flow Characteristics ◽  
Near Wake

Influence of rotation on the near-wake development behind an impulsively started circular cylinder

1985 ◽  
Vol 158 ◽  
pp. 399-446 ◽  
Author(s):  
Madeleine Coutanceau ◽  
Christian Ménard
Keyword(s):  
Circular Cylinder ◽  
Stokes Equations ◽  
Flow Characteristics ◽  
Navier Stokes ◽  
Speed Ratio ◽  
Flow Topology ◽  
Near Wake ◽  
Navier Stokes Equations ◽  
Magnus Effect ◽  
Point Trajectories

The early phase of the establishment of the flow past a circular cylinder started impulsively into rotation and translation is investigated by visualizing the flow patterns with solid tracers and by analysing qualitatively (flow topology) and quantitatively (velocity distributions and singular-point trajectories) the corresponding photographs. The range considered corresponds to moderate Reynolds numbers (Re [les ] 1000). The rotating-to-translating-speed ratio α increases from 0 to 3.25 and the motion covers a period during which the cylinder translates 4.5 or even 7 times its diameter. The details of the mechanisms of the near-wake formation are considered in particular and the increase of the flow asymmetry with increase in rotation is pointed out. Thus the existence of two regimes has been confirmed with the creation or non-creation of alternate eddies after an initial one E1 Furthermore, the new phenomena of saddle-point transposition and intermediate-eddy coalescence have been identified in the formation or shedding of respectively the odd and even subsequent eddies Ei (i = 2,3,…) when they exist. The very good agreement between these experimental data and the numerical results of Badr & Dennis (1985), obtained by solving the Navier-Stokes equations and presented in a parallel paper, confirms their respective validity and permits the determination of the flow characteristics not accessible, or accessible only with difficulty, to the present experiments. These flow properties such as drag and vorticity are capable of providing information on the Magnus effect for the former property and on unsteady separated flows for the latter.

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.

Laminar Near Wake of a Circular Cylinder at Hypersonic Speeds

AIAA Journal ◽  
2010 ◽  
Vol 48 (1) ◽  
pp. 236-248 ◽  
Author(s):  
Gisu Park ◽  
Sudhir L. Gai ◽  
Andrew J. Neely
Keyword(s):  
Circular Cylinder ◽  
Near Wake ◽  
Hypersonic Speeds

Observations on the Near Wake of a Yawed Circular Cylinder

1993 ◽  
pp. 257-284 ◽  
Author(s):  
L. Lourenco ◽  
C. Shih ◽  
A. Krothapalli
Keyword(s):  
Circular Cylinder ◽  
Near Wake

Wavelet patterns in the near wake of a circular cylinder and a porous mesh strip

1999 ◽  
pp. 381-390 ◽  
Author(s):  
H. Hangan ◽  
G.A. Kopp ◽  
A. Vernet ◽  
R. Martinuzzi
Keyword(s):  
Circular Cylinder ◽  
Near Wake
Sign in / Sign up

Export Citation Format

Share Document