Variational multiscale large-eddy simulations of the flow past a circular cylinder: Reynolds number effects

2011 ◽  
Vol 47 (1) ◽  
pp. 44-50 ◽  
Author(s):  
Stephen Wornom ◽  
Hilde Ouvrard ◽  
Maria Vittoria Salvetti ◽  
Bruno Koobus ◽  
Alain Dervieux
Keyword(s):  
Reynolds Number ◽  
Circular Cylinder ◽  
Large Eddy Simulations ◽  
Variational Multiscale ◽  
Flow Past ◽  
Large Eddy ◽  
Reynolds Number Effects

A Parametric Study of Turbulent Flow Past a Circular Cylinder Using Large Eddy Simulation

2015 ◽  
Vol 137 (9) ◽  
Author(s):  
W. Sidebottom ◽  
A. Ooi ◽  
D. Jones
Keyword(s):  
Reynolds Number ◽  
Finite Difference ◽  
Circular Cylinder ◽  
Stokes Equations ◽  
Finite Difference Methods ◽  
Large Eddy Simulations ◽  
Near Wake ◽  
Flow Past ◽  
Large Eddy ◽  
Difference Methods

Flow over a circular cylinder at a Reynolds number of 3900 is investigated using large eddy simulations (LES) to assess the affect of four numerical parameters on the resulting flow-field. These parameters are subgrid scale (SGS) turbulence models, wall models, discretization of the advective terms in the governing equations, and grid resolution. A finite volume method is employed to solve the incompressible Navier–Stokes equations (NSE) on a structured grid. Results are compared to the experiments of Ong and Wallace (1996, “The Velocity Field of the Turbulent Very Near Wake of a Circular Cylinder,” Exp. Fluids, 20(6), pp. 441–453) and Lourenco and Shih (1993, “Characteristics of the Plane Turbulent Near Wake of a Circular Cylinder: A Particle Image Velocimetry Study,” private communication (taken from Ref. [2]); and the numerical results of Beaudan and Moin (1994, “Numerical Experiments on the Flow Past a Circular Cylinder at Sub-Critical Reynolds Number,” Technical Report No. TF-62), Kravchenko and Moin (2000, “Numerical Studies of Flow Over a Circular Cylinder at ReD = 3900,” Phys. Fluids, 12(2), pp. 403–417), and Breuer (1998, “Numerical and Modelling Influences on Large Eddy Simulations for the Flow Past a Circular Cylinder,” Int. J. Heat Fluid Flow, 19(5), pp. 512–521). It is concluded that the effect of the SGS models is not significant; results with and without a wall model are inconsistent; nondissipative discretization schemes, such as central finite difference methods, are preferred over dissipative methods, such as upwind finite difference methods; and it is necessary to properly resolve the boundary layer in the vicinity of the cylinder in order to accurately model the complex flow phenomena in the cylinder wake. These conclusions are based on the analysis of bulk flow parameters and the distribution of mean and fluctuating quantities throughout the domain. In general, results show good agreement with the experimental and numerical data used for comparison.

Detailed Investigation of Detached-Eddy Simulation for the Flow Past a Circular Cylinder at Re=3900

2012 ◽  
Vol 232 ◽  
pp. 471-476 ◽  
Author(s):  
Rui Zhao ◽  
Chao Yan
Keyword(s):  
Reynolds Number ◽  
Circular Cylinder ◽  
Flow Structures ◽  
Detached Eddy Simulation ◽  
Eddy Simulation ◽  
Flow Past ◽  
Large Eddy ◽  
Mesh Resolution ◽  
Physical Phenomena

The flow past a circular cylinder at a subcritical Reynolds number 3900 was simulated by the method of detached-eddy simulation (DES). The objective of this present work is not to investigate the physical phenomena of the flow but to study modeling as well as numerical aspects which influence the quality of DES solutions in detail. Firstly, four typical spanwise lengths are chosen and the results are systematically compared. The trend of DES results along the span increment is different from previous large-eddy simulation (LES) investigation. A wider spanwise length does not necessary improve the results. Then, the influence of mesh resolution is studied and found that both too coarse and over refined grids will deteriorate the performance of DES. Finally, different orders of numerical schemes are applied in the inviscid fluxes and the viscous terms. The discrepancies among different schemes are found tiny. However, the instantaneous flow structures produced by 5th order WENO with 4th order central differencing scheme are more abundant than the others. That is, for the time-averaged quantities, the second-order accurate schemes are effective enough, whereas the higher-order accurate methods are needed to resolve the transient characteristics of the flow.

Flow Dynamics and Heat Transfer of a Stranded Overhead Conductor Cable

2020 ◽  
Author(s):  
Mohamed Abdelhady ◽  
David H. Wood
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Circular Cylinder ◽  
Coherent Structures ◽  
Carrying Capacity ◽  
Orthogonal Decomposition ◽  
Flow Dynamics ◽  
Large Eddy Simulations ◽  
Large Eddy ◽  
Proper Orthogonal

Abstract Stranded overhead conductor cables are used to transfer electric power, often over large distances. Conductor geometry, as well as environmental conditions, affect the power carrying capacity. This paper studies the flow dynamics and heat transfer for one stranded conductor geometry in air at Reynolds number of 1,000, determined using dynamic Smagorinsky Large Eddy Simulations. Proper Orthogonal Decomposition was used to identify coherent structures. In comparison to a smooth circular cylinder, the conductor strands noticeably affect the flow dynamics and heat transfer, locally and globally.

Large-eddy simulations of flow past a circular cylinder near a free surface

2021 ◽  
Vol 33 (11) ◽  
pp. 115108
Author(s):  
Feng Zhao ◽  
Rui Wang ◽  
Hongbo Zhu ◽  
Huang Ping ◽  
Yan Bao ◽  
...  
Keyword(s):  
Free Surface ◽  
Circular Cylinder ◽  
Large Eddy Simulations ◽  
Flow Past ◽  
Large Eddy

Control of an Incompressible Turbulent Flow Past a Circular Cylinder Computed by Large Eddy Simulation

2002 ◽  
Author(s):  
Guillaume Fournier ◽  
Ste´phanie Pellerin ◽  
Loc Ta Phuoc
Keyword(s):  
Circular Cylinder ◽  
Turbulent Flow ◽  
Large Eddy Simulations ◽  
Control Methods ◽  
Aerodynamic Coefficients ◽  
Boundary Layer Suction ◽  
Eddy Simulation ◽  
Flow Past ◽  
Large Eddy ◽  
Cylinder Rotation

Large Eddy Simulations are performed on a turbulent flow past a circular cylinder with control using velocity-vorticity formulation. The effect of two control methods is analyzed considering aerodynamic coefficients. The influence of rotation and suction velocities is studied. The cylinder rotation and the boundary layer suction induce a lift creation and an increase of lift with control magnitude. Lift value also depends strongly on the suction location which has to be in the vicinity of the separation point.

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