Turbulent flow and heat flux analysis from validated large eddy simulations of flow past a heated cylinder in the near wake region

2020 ◽  
Vol 32 (12) ◽  
pp. 125119
Author(s):  
Arpan Sircar ◽  
Mark Kimber ◽  
Srujan Rokkam ◽  
Gerrit Botha
Keyword(s):  
Heat Flux ◽  
Turbulent Flow ◽  
Large Eddy Simulations ◽  
Flux Analysis ◽  
Wake Region ◽  
Near Wake ◽  
Heated Cylinder ◽  
Flow Past ◽  
Large Eddy

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.

Investigation of Conduit Flow Past Corrugated Structures Using Large Eddy Simulations

2019 ◽  
Author(s):  
Sushrut Kumar ◽  
Ujjwal Suri ◽  
Paras Sachdeva ◽  
Raj Kumar Singh
Keyword(s):  
Turbulent Flow ◽  
Velocity Component ◽  
Large Eddy Simulations ◽  
Three Dimensions ◽  
Scale Model ◽  
Particle Injection ◽  
Cross Sectional ◽  
Flow Past ◽  
Subsequent Decrease ◽  
Large Eddy

Abstract The present paper studies the characteristics of a fully turbulent flow of water through a conduit by use of corrugated structures. Methodologies including rough-ribbed walls and particle injection have been utilized for turbulence attenuation in the past. Screens and corrugations are yet another effective tools for reducing turbulence. The proposed investigation focuses on the application of square and hexagonal cross-sectional corrugations which are introduced in the flow for turbulence attenuation inside rectangular conduits. Large Eddy Simulations in three dimensions were performed with OpenFOAM using a pressure-implicit solver and the standard Smagorinsky subgrid-scale model. Dampening of the spanwise velocity component and a relative increase in streamwise velocity component downstream of the corrugation was observed. The power spectral densities (PSD) of the flow upstream and downstream of the corrugation were examined and compared. A significant decrease in turbulent flow power density was observed. Furthermore, characteristics including turbulence intensity contours and isosurfaces of the Q-criterion were visualized. The results conclusively indicate a subsequent decrease in the turbulent nature of flow past corrugated structures.

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.

scholarly journals Brief communication: A double Gaussian wake model

2019 ◽  
Author(s):  
Johannes Schreiber ◽  
Amr Balbaa ◽  
Carlo L. Bottasso
Keyword(s):  
Shape Function ◽  
Gaussian Model ◽  
Large Eddy Simulations ◽  
Wake Region ◽  
Near Wake ◽  
Stream Tube ◽  
Gaussian Shape ◽  
Large Eddy ◽  
Conservation Of Momentum ◽  
Wake Model

Abstract. In this paper, an analytical wake model with a double Gaussian velocity distribution is presented, improving on a similar formulation by Keane et al. The choice of a double Gaussian shape function is motivated by the behavior of the near wake region, observed in numerical simulations and experimental measurements. The method is based on the conservation of momentum principle, while stream-tube theory is used to determine the wake expansion at the tube outlet. The model is calibrated and validated using large eddy simulations replicating scaled wind turbine experiments. Results show that the tuned double Gaussian model is superior to a single Gaussian formulation in the near wake region.

scholarly journals Brief communication: A double-Gaussian wake model

2020 ◽  
Vol 5 (1) ◽  
pp. 237-244 ◽  
Author(s):  
Johannes Schreiber ◽  
Amr Balbaa ◽  
Carlo L. Bottasso
Keyword(s):  
Shape Function ◽  
Gaussian Model ◽  
Large Eddy Simulations ◽  
Wake Region ◽  
Near Wake ◽  
Stream Tube ◽  
Gaussian Shape ◽  
Large Eddy ◽  
Conservation Of Momentum ◽  
Wake Model

Abstract. In this paper, an analytical wake model with a double-Gaussian velocity distribution is presented, improving on a similar formulation by Keane et al. (2016). The choice of a double-Gaussian shape function is motivated by the behavior of the near-wake region that is observed in numerical simulations and experimental measurements. The method is based on the conservation of momentum principle, while stream-tube theory is used to determine the wake expansion at the tube outlet. The model is calibrated and validated using large eddy simulations replicating scaled wind turbine experiments. Results show that the tuned double-Gaussian model is superior to a single-Gaussian formulation in the near-wake region.

Large-eddy simulation of turbulent flow past wind turbines/farms: the Virtual Wind Simulator (VWiS)

Wind Energy ◽  
2014 ◽  
Vol 18 (12) ◽  
pp. 2025-2045 ◽  
Author(s):  
Xiaolei Yang ◽  
Fotis Sotiropoulos ◽  
Robert J. Conzemius ◽  
John N. Wachtler ◽  
Mike B. Strong
Keyword(s):  
Large Eddy Simulation ◽  
Turbulent Flow ◽  
Wind Turbines ◽  
Eddy Simulation ◽  
Flow Past ◽  
Large Eddy

scholarly journals Dynamic LES of the magnetohydrodynamic flow in a square duct with the varied wall conductance parameters

2021 ◽  
Vol 2116 (1) ◽  
pp. 012036
Author(s):  
A Blishchik ◽  
S Kenjereš
Keyword(s):  
Electrical Conductivity ◽  
Turbulent Flow ◽  
Magnetohydrodynamic Flow ◽  
Large Eddy Simulations ◽  
Scale Model ◽  
Turbulent Structures ◽  
Square Duct ◽  
Large Eddy ◽  
Side Walls

Abstract The current study is focused on the magnetohydrodynamics and demonstrates how electrical conductivity of the wall can affect the turbulent flow in the square duct. Different variations of the boundary walls have been considered including arbitrary conductive walls. The Large Eddy Simulations method with the dynamic Smagorinsky sub-grid scale model have been used for the turbulent structures resolving. Results show the significant impact of the wall conductance parameters for both Hartmann and side walls.

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