Closure to “Discussion of ‘Effect of Wind Tunnel Walls on the Flow Past Circular Cylinders and Cooling Tower Models’” (1977, ASME J. Fluids Eng., 99, p. 785)

1977 ◽  
Vol 99 (4) ◽  
pp. 785-786
Author(s):  
C. Farell ◽  
O. Guven ◽  
S. Carrasquel ◽  
V. Patel
Keyword(s):  
Wind Tunnel ◽  
Cooling Tower ◽  
Circular Cylinders ◽  
Flow Past

Effect of Wind-Tunnel Walls on the Flow Past Circular Cylinders and Cooling Tower Models

1977 ◽  
Vol 99 (3) ◽  
pp. 470-479 ◽  
Author(s):  
Ce´sar Farell ◽  
Saul Carrasquel ◽  
Oktay Gu¨ven ◽  
V. C. Patel
Keyword(s):  
Surface Roughness ◽  
Reynolds Number ◽  
Wind Tunnel ◽  
Cooling Tower ◽  
Pressure Coefficient ◽  
Base Pressure ◽  
Circular Cylinders ◽  
Cooling Towers ◽  
Number Range ◽  
Geometry Model

The effect of wind tunnel walls on the mean pressure distributions on rough-walled circular cylinders and on cooling tower models fitted with longitudinal ribs is studied experimentally in the range of Reynolds-number independence. For circular cylinders the results are compared with analytical corrections based on formulae of Allen and Vincenti, and of Maskell, which are found to be generally applicable in this Reynolds number range. For cooling towers, a correction procedure is proposed using the base pressure coefficient, Cpb, and the dimensionless pressure rise to separation, Cpb–Cpm, where Cpm is the minimum value of the pressure coefficient. The base pressure coefficient Cpb for cooling towers is (in the Reynolds-number-independent range) a function of the boundary geometry: model shape, tunnel type (open or closed jet) and blockage, and is independent of surface roughness. The difference Cpb–Cpm, on the other hand, is mainly a function of surface roughness for both cylinders and cooling towers and is very little, if at all, affected by tunnel blockage for blockages less than, say, 15 percent.

The supersonic and low-speed flows past circular cylinders of finite length supported at one end

1962 ◽  
Vol 12 (3) ◽  
pp. 367-387 ◽  
Author(s):  
D. M. Sykes
Keyword(s):  
Mach Number ◽  
Finite Length ◽  
Central Region ◽  
Diameter Ratio ◽  
Circular Cylinders ◽  
Form Drag ◽  
Drag Coefficients ◽  
Low Speed ◽  
Flow Past ◽  
Length To Diameter Ratio

The flow past circular cylinders of finite length, supported at one end and lying with their axes perpendicular to a uniform stream, has been investigated in a supersonic stream at Mach number 1.96 and also in a low-speed stream. In both stream it was found that the flow past the cylinders could be divided into three regions: (a) a central region, (b) that near the free end of the cylinder, and (c) that near the supported end. The locations of the second and third regions were found to be almost independent of the cylinder length-to-diameter ratio, provided that this exceeded 4, while the flow within and the extent of the first region were dependent on this ratio. Form-drag coefficients determined in the central region in the supersonic flow were in close agreement with the values determined at the same Mach number by other workers. In the low-speed flow the local form-drag coefficients were dependent on length-to-diameter ratio and were always less than that of an infinite-length cylinder at the same Reynolds number.

Steady approach of unsteady low-Reynolds-number flow past two rotating circular cylinders

2013 ◽  
Vol 736 ◽  
pp. 414-443 ◽  
Author(s):  
Y. Ueda ◽  
T. Kida ◽  
M. Iguchi
Keyword(s):  
Reynolds Number ◽  
Circular Cylinder ◽  
Stokes Equations ◽  
Low Reynolds Number ◽  
Vortex Method ◽  
The Self ◽  
Circular Cylinders ◽  
Far Field ◽  
Flow Past ◽  
Low Reynolds

AbstractThe long-time viscous flow about two identical rotating circular cylinders in a side-by-side arrangement is investigated using an adaptive numerical scheme based on the vortex method. The Stokes solution of the steady flow about the two-cylinder cluster produces a uniform stream in the far field, which is the so-called Jeffery’s paradox. The present work first addresses the validation of the vortex method for a low-Reynolds-number computation. The unsteady flow past an abruptly started purely rotating circular cylinder is therefore computed and compared with an exact solution to the Navier–Stokes equations. The steady state is then found to be obtained for $t\gg 1$ with ${\mathit{Re}}_{\omega } {r}^{2} \ll t$, where the characteristic length and velocity are respectively normalized with the radius ${a}_{1} $ of the circular cylinder and the circumferential velocity ${\Omega }_{1} {a}_{1} $. Then, the influence of the Reynolds number ${\mathit{Re}}_{\omega } = { a}_{1}^{2} {\Omega }_{1} / \nu $ about the two-cylinder cluster is investigated in the range $0. 125\leqslant {\mathit{Re}}_{\omega } \leqslant 40$. The convection influence forms a pair of circulations (called self-induced closed streamlines) ahead of the cylinders to alter the symmetry of the streamline whereas the low-Reynolds-number computation (${\mathit{Re}}_{\omega } = 0. 125$) reaches the steady regime in a proper inner domain. The self-induced closed streamline is formed at far field due to the boundary condition being zero at infinity. When the two-cylinder cluster is immersed in a uniform flow, which is equivalent to Jeffery’s solution, the streamline behaves like excellent Jeffery’s flow at ${\mathit{Re}}_{\omega } = 1. 25$ (although the drag force is almost zero). On the other hand, the influence of the gap spacing between the cylinders is also investigated and it is shown that there are two kinds of flow regimes including Jeffery’s flow. At a proper distance from the cylinders, the self-induced far-field velocity, which is almost equivalent to Jeffery’s solution, is successfully observed in a two-cylinder arrangement.

Three-dimensional flow past two stationary side-by-side circular cylinders

2022 ◽  
Vol 244 ◽  
pp. 110379
Author(s):  
Weilin Chen ◽  
Chunning Ji ◽  
Md. Mahbub Alam ◽  
Yuhao Yan
Keyword(s):  
Three Dimensional ◽  
Circular Cylinders ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Flow Past

A comparison of mesh-adaptive LES with wind tunnel data for flow past buildings: Mean flows and velocity fluctuations

2009 ◽  
Vol 43 (39) ◽  
pp. 6238-6253 ◽  
Author(s):  
Elsa Aristodemou ◽  
Tom Bentham ◽  
Christopher Pain ◽  
Roy Colvile ◽  
Alan Robins ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Velocity Fluctuations ◽  
Flow Past ◽  
Wind Tunnel Data

Viscous flow past circular cylinders

1973 ◽  
Vol 1 (1) ◽  
pp. 59-71 ◽  
Author(s):  
F. Nieuwstadt ◽  
H.B. Keller
Keyword(s):  
Viscous Flow ◽  
Circular Cylinders ◽  
Flow Past
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