Modeling of Effect of Inflow Turbulence Data on Large Eddy Simulation of Circular Cylinder Flows

2006 ◽  
Vol 129 (6) ◽  
pp. 780-790 ◽  
Author(s):  
M. Tutar ◽  
I. Celik ◽  
I. Yavuz
Keyword(s):  
Reynolds Number ◽  
Circular Cylinder ◽  
Large Eddy Simulation ◽  
Boundary Conditions ◽  
Wake Flow ◽  
Eddy Simulation ◽  
Turbulent Inflow ◽  
Large Eddy ◽  
Inflow Turbulence ◽  
Near Wall

A random flow generation (RFG) algorithm for a previously established large eddy simulation (LES) code is successfully incorporated into a finite element fluid flow solver to generate the required inflow/initial turbulence boundary conditions for the three-dimensional (3D) LES computations of viscous incompressible turbulent flow over a nominally two-dimensional (2D) circular cylinder at Reynolds number of 140,000. The effect of generated turbulent inflow boundary conditions on the near wake flow and the shear layer and on the prediction of integral flow parameters is studied based on long time average results. Because the near-wall region cannot be resolved for high Reynolds number flows, no-slip velocity boundary function is used, but wall effects are taken into consideration with a near-wall modeling methodology that comprises the no-slip function with a modified form of van Driest damping approach to reduce the subgrid length scale in the vicinity of the cylinder wall. Simulations are performed for a 2D and a 3D configuration, and the simulation results are compared to each other and to the experimental data for different turbulent inflow boundary conditions with varying degree of inflow turbulence to assess the functionality of the RFG algorithm for the present LES code and, hence, its influence on the vortex shedding mechanism and the resulting flow field predictions.

A Dynamic Procedure for Wall-Modeled Large-Eddy Simulation of High Reynolds Number Flows

2011 ◽  
Author(s):  
Soshi Kawai
Keyword(s):  
Reynolds Number ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Large Eddy Simulation ◽  
High Reynolds Number ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Wall Shear ◽  
High Reynolds ◽  
Near Wall

This paper addresses the error in large-eddy simulation with wall-modeling (i.e., when the wall shear stress is modeled and the viscous near-wall layer is not resolved): the error in estimating the wall shear stress from a given outer-layer velocity field using auxiliary near-wall RANS equations where convection is not neglected. By considering the behavior of turbulence length scales near a wall, the cause of the errors is diagnosed and solutions that remove the errors are proposed based solidly on physical reasoning. The resulting method is shown to accurately predict equilibrium boundary layers at very high Reynolds number, with both realistic instantaneous fields (without overly elongated unphysical near-wall structures) and accurate statistics (both skin friction and turbulence quantities).

scholarly journals EFFECT OF THE SPANWISE DISCRETISATION ON TURBULENT FLOW PAST A CIRCULAR CYLINDER

2021 ◽  
Vol 158 (A1) ◽  
Author(s):  
S Kim ◽  
P A Wilson ◽  
Z Chen
Keyword(s):  
Reynolds Number ◽  
Circular Cylinder ◽  
Flow Field ◽  
Large Eddy Simulation ◽  
Turbulent Flow ◽  
Three Dimensional ◽  
Scale Model ◽  
Spatial Density ◽  
Eddy Simulation ◽  
Large Eddy

The effect of the spanwise discretisation on numerical calculations of the turbulent flow around a circular cylinder is systematically assessed at a subcritical Reynolds number of 10000 in the frame of three-dimensional large-eddy simulation. The eddy-viscosity k-equation subgrid scale model is implemented to evaluate unsteady turbulent flow field. Large-eddy simulation is known to be a reliable method to resolve such a challenging flow field, however, the high computational efforts restrict to low Reynolds number flow or two-dimensional calculations. Therefore, minimum spatial density in the spanwise direction or cylinder axis direction needs to be carefully evaluated in order to reduce high computational resources. In the present study, the influence of the spanwise resolutions to satisfactorily represent three- dimensional complex flow features is discussed in detail and minimum spatial density for high Reynolds flow is suggested.

Large-Eddy Simulation of the Flow Over a Circular Cylinder at Reynolds Number 2 × 104

2013 ◽  
Vol 92 (3) ◽  
pp. 673-698 ◽  
Author(s):  
Dmitry A. Lysenko ◽  
Ivar S. Ertesvåg ◽  
Kjell Erik Rian
Keyword(s):  
Reynolds Number ◽  
Circular Cylinder ◽  
Large Eddy Simulation ◽  
Eddy Simulation ◽  
Large Eddy

Large Eddy Simulation of Turbulent Heat Transfer Around a Circular Cylinder in Crossflow

2007 ◽  
Author(s):  
Sung-Eun Kim ◽  
Hajime Nakamura
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Circular Cylinder ◽  
Large Eddy Simulation ◽  
Turbulent Heat Transfer ◽  
Turbulent Heat ◽  
Heat Transfer Characteristics ◽  
Eddy Simulation ◽  
Flow And Heat Transfer ◽  
Large Eddy

Large eddy simulation has been carried out of turbulent flow and heat transfer around a circular cylinder in crossflow at three subcritical Reynolds numbers (Re = 3,900, 10,000, 18,900) where the flow and heat transfer characteristics change rapidly with the Reynolds number. The computations were carried out using a second-order-accurate finite-volume Navier-Stokes solver that permits use of arbitrary unstructured meshes. A fully implicit, non-iterative fractional-step method was employed to advance the solution in time. The subgrid-scale (SGS) turbulent stresses and heat fluxes were modeled using the dynamic Smagorinsky model. The LES predictions were found to be in good agreement with the experimental data of Hajime and Igarashi (2004). The salient features of turbulent heat transfer in subcritical regime such as the laminar thermal boundary layer and the rapid increase with Reynolds number both in the mean and the r.m.s. Nusselt number in the separated region are closely reproduced by the predictions. The numerical results confirmed that the heat transfer characteristics are closely correlated with the structural change in the underlying flow with the Reynolds number.

An Anisotropic Subgrid Model for Large Eddy Simulation of Wall Bounded Turbulent Flows

2007 ◽  
Author(s):  
Sachin S. Badarayani ◽  
Kyle D. Squires
Keyword(s):  
Reynolds Number ◽  
Large Eddy Simulation ◽  
Velocity Profile ◽  
Turbulent Flows ◽  
Model Parameters ◽  
Wall Region ◽  
Outer Flow ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Near Wall

Large Eddy Simulation (LES) of high-Reynolds-number wall-bounded turbulent flows is prohibitively expensive if the energy-containing eddies in the near-wall region are resolved. This motivates the use of wall-layer models in which an approximate solution of the near wall dynamics is bridged to an LES of the outer flow. The main interest of the present work are wall-modeling strategies based on Detached Eddy Simulation (DES). In these approaches, the near-wall solution is closed using a Reynolds-averaged Navier Stokes model with a subgrid closure applied to the outer flow. As is well known, the original DES formulation applied directly as a wall model results in a shift in the velocity profile, corresponding to an under-estimation of the skin friction. A new formulation is proposed in this contribution in which the wall-parallel components of the modeled stress are reduced in order to lower the influence of the model and increase the resolved stress. The effectiveness of the new model is evaluated via comparison against DES predictions using the original and recently-proposed versions of the method. The effect of grid resolution and model parameters are also assessed using computations of turbulent channel flow at a Reynolds number based on friction velocity and channel halfwidth of 5000. The predictions show that the anisotropic form of the model stress yields an improved prediction of the mean velocity profile in better agreement with the logarithmic law and with larger resolved stress in the near-wall region.

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